[Federal Register Volume 77, Number 67 (Friday, April 6, 2012)]
[Rules and Regulations]
[Pages 20948-20986]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2012-8088]



[[Page 20947]]

Vol. 77

Friday,

No. 67

April 6, 2012

Part III





Department of the Interior





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Fish and Wildlife Service





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50 CFR Part 17





Endangered and Threatened Wildlife and Plants; Listing of the Miami 
Blue Butterfly as Endangered Throughout Its Range; Listing of the 
Cassius Blue, Ceraunus Blue, and Nickerbean Blue Butterflies as 
Threatened Due to Similarity of Appearance to the Miami Blue Butterfly 
in Coastal South and Central Florida; Final Rule

  Federal Register / Vol. 77, No. 67 / Friday, April 6, 2012 / Rules 
and Regulations  

[[Page 20948]]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R4-ES-2011-0043; 4500030113]
RIN 1018-AX83


Endangered and Threatened Wildlife and Plants; Listing of the 
Miami Blue Butterfly as Endangered Throughout Its Range; Listing of the 
Cassius Blue, Ceraunus Blue, and Nickerbean Blue Butterflies as 
Threatened Due to Similarity of Appearance to the Miami Blue Butterfly 
in Coastal South and Central Florida

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Final rule.

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SUMMARY: We, the Fish and Wildlife Service (Service), are listing the 
Miami blue butterfly (Cyclargus thomasi bethunebakeri), as endangered 
under the Endangered Species Act of 1973, as amended (Act). We have 
determined that designation of critical habitat for the Miami blue 
butterfly is not prudent at this time. We also are listing the cassius 
blue butterfly (Leptotes cassius theonus), ceraunus blue butterfly 
(Hemiargus ceraunus antibubastus), and nickerbean blue butterfly 
(Cyclargus ammon) as threatened due to similarity of appearance to the 
Miami blue in coastal south and central Florida, and establishing a 
special rule under section 4(d) of the Act for these three species.

DATES: This final rule becomes effective on April 6, 2012.

ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and http://www.fws.gov/verobeach/. Comments and 
materials received, as well as supporting documentation used in the 
preparation of this rule, will be available for inspection, by 
appointment, during normal business hours at the U.S. Fish and Wildlife 
Service, South Florida Ecological Services Office, 1339 20th Street, 
Vero Beach, Florida 32960-3559; telephone 772-562-3909; facsimile 772-
562-4288.

FOR FURTHER INFORMATION CONTACT: Larry Williams, Field Supervisor, U.S. 
Fish and Wildlife Service, South Florida Ecological Services Office 
(see ADDRESSES above). If you use a telecommunications device for the 
deaf (TDD), call the Federal Information Relay Service (FIRS) at 800-
877-8339.

SUPPLEMENTARY INFORMATION: 

Executive Summary

    This document consists of: (1) A final rule to list the Miami blue 
butterfly (Cyclargus thomasi bethunebakeri) as endangered; and (2) a 
special rule pursuant to section 4(d) of the Act to list the cassius 
blue butterfly (Leptotes cassius theonus), ceraunus blue butterfly 
(Hemiargus ceraunus antibubastus), and nickerbean blue butterfly 
(Cyclargus ammon) as threatened due to similarity of appearance to the 
Miami blue in portions of their ranges.
    Why we need to publish a rule. Under the Act, a species or 
subspecies may warrant protection through listing if it is endangered 
or threatened throughout all or a significant portion of its range. On 
August 10, 2011, we published emergency and proposed rules to list the 
Miami blue butterfly as endangered. In those documents we explained 
that the subspecies currently exists in a fraction of its historical 
range and faces numerous threats, and therefore qualifies for listing. 
This rule finalizes the protection proposed for the subspecies, 
following careful consideration of all comments received during the 
public comment period. One of the principal threats to the subspecies 
is collection for commercial purposes. For this reason, we are also 
prohibiting the collection of the cassius, ceraunus, and nickerbean 
blue butterflies, three species which are very similar in appearance to 
the Miami blue butterfly, within the historical range of the Miami 
blue.
    The basis for our action. Under the Act, a species may be 
determined to be endangered or threatened based on any of five factors: 
(1) Destruction, modification, or curtailment of its habitat or range; 
(2) Overutilization; (3) Disease or predation; (4) Inadequate existing 
regulations; or (5) Other natural or manmade factors. The Miami blue is 
endangered due to four of these five factors. Section 4(e) of the Act 
also allows for the extension of protections to similar species under 
certain circumstances.
    Peer reviewers support our methods. We solicited opinions from 
knowledgeable individuals with scientific expertise to review the 
technical assumptions, analyses, adherence to regulations, and whether 
or not we had used the best available information in our proposed 
listing rule for the subspecies. We received 8 peer review responses, 
and 2 collaborative responses from State agencies. These peer reviewers 
generally concurred with the basis for listing the Miami blue, and 
provided additional information, clarifications, and suggestions to 
improve this final listing determination.

Acronyms Used in This Document

    We use many acronyms throughout this final rule. To assist the 
reader, we provide a list of these acronyms here for easy reference:

AME = Allyn Museum of Entomology
BHSP = Bahia Honda State Park
BNP = Biscayne National Park
CCSP = U.S. Climate Change Science Program
CITES = Convention on International Trade in Endangered Species
DJSP = Dagny Johnson Key Largo Hammock Botanical State Park
ENP = Everglades National Park
FCCMC = Florida Coordinating Council on Mosquito Control
FDEP = Florida Department of Environmental Protection
FKMCD = Florida Keys Mosquito Control District
FLMNH = Florida Museum of Natural History
FPS = Florida Park Service
FWC = Florida Fish and Wildlife Conservation Commission
GWHNWR = Great White Heron National Wildlife Refuge
INRMP = Integrated Natural Resource Management Plan
IPCC = Intergovernmental Panel on Climate Change
IRC = Institute for Regional Conservation
KWNWR = Key West National Wildlife Refuge
MIT = Massachusetts Institute of Technology
NABA = North American Butterfly Association
NAS = Naval Air Station Key West
NCSU = North Carolina State University
NEP = nonessential experimental populations
NKDR = National Key Deer Refuge
TNC = The Nature Conservancy
UF = University of Florida
UN = United Nations
USDJ = U.S. Department of Justice
USGS = U.S. Geological Survey

Previous Federal Actions

    Federal actions for the Miami blue butterfly prior to August 10, 
2011, are outlined in our emergency rule (76 FR 49542), which was 
published on that date. Publication of the proposed rule (76 FR 49408), 
concurrently published on that date, opened a 60-day comment period, 
which closed on October 11, 2011. The emergency rule provides 
protection for the Miami blue, ceraunus blue, nickerbean blue, and 
cassius blue butterflies for a 240-day period, ending on April 6, 2012. 
Because of this time constraint, and the threat of collection of these 
species if the emergency rule expires before the proposed rule is 
finalized (see Factor B, Overutilization for commercial, recreational, 
scientific, or educational purposes), this rule does not have the 
standard 30-day period

[[Page 20949]]

before becoming effective. It becomes effective upon the expiration of 
the emergency rule, April 6, 2012.

Public Comments

    We received comments from the public on the proposed listing 
action, including the proposed listing of three similar butterflies due 
to similarity of appearance and our determination that designation of 
critical habitat is not prudent. In this rule, we respond to these 
issues in a single comment section.

Background

    The Miami blue is a small, brightly colored butterfly approximately 
0.8 to 1.1 inches (1.9 to 2.9 centimeters [cm]) in length (Pyle 1981, 
p. 488), with a forewing length of 0.3 to 0.5 inches (8.0 to 12.5 
millimeters) (Minno and Emmel 1993, p. 134). Wings of males are blue 
above (dorsally), with a narrow black outer border and white fringes; 
females are bright blue dorsally, with black borders and an orange/red 
and black eyespot near the anal angle of the hindwing (Comstock and 
Huntington 1943, p. 98; Minno and Emmel 1993, p. 134). The underside is 
grayish, with darker markings outlined with white and bands of white 
wedges near the outer margin. The ventral hindwing has two pairs of 
eyespots, one of which is capped with red; basal and costal spots on 
the hindwing are black and conspicuous (Minno and Emmel 1993, p. 134). 
The winter (dry season) form is much lighter blue than the summer (wet 
season) form and has narrow black borders (Opler and Krizek 1984, p. 
112). Seasonal wing pattern variation may be caused by changes in 
humidity, temperature, or length of day (Pyle 1981, p. 489). Miami blue 
larvae are bright green with a black head capsule, and pupae vary in 
color from black to brown (Minno and Emmel 1993, pp. 134-135).
    The Miami blue is similar in appearance to three other sympatric 
(occupying the same or overlapping geographic areas, without 
interbreeding) butterfly species that occur roughly in the same 
habitats: cassius blue (Leptotes cassius theonus), ceraunus blue 
(Hemiargus ceraunus antibubastus), and nickerbean blue (Cyclargus 
ammon). The Miami blue is slightly larger than the ceraunus blue (Minno 
and Emmel 1993, p. 134), and the ceraunus blue has a different ventral 
pattern and flies close to the ground in open areas (Minno and Emmel 
1994, p. 647). The cassius blue often occurs with the Miami blue, but 
has dark bars rather than spots on the undersides of the wings (Minno 
and Emmel 1994, p. 647). The Miami blue can be distinguished from the 
ceraunus blue and cassius blue by its very broad white ventral 
submarginal band, the dorsal turquoise color of both sexes, and the 
orange-capped marginal eyespot on the hind wings (Opler and Krizek 
1984, p. 112). The nickerbean blue is also similar to the Miami blue in 
general appearance but is considerably smaller; it has three black 
spots across the basal hindwing, while the Miami blue has four (Calhoun 
et al. 2002, p. 15). The larvae and pupae of the nickerbean blue 
closely resemble the Miami blue (Calhoun et al. 2002, p. 15).
    In a comparison of Miami blue butterfly specimens within the 
Florida Museum of Natural History (FLMNH) collection, Saarinen (2009, 
pp. 42-43) found a significant difference in forewing length between 
males and females, with males having shorter forewings than females. 
However, no significant differences were found between forewing length 
in comparing wet and dry seasons, decade of collection, seven different 
regions, or between eastern mainland and Keys specimens (Saarinen 2009, 
pp. 42-43). No seasonal size differences were found between the 
mainland populations and those in the Keys (Saarinen 2009, p. 43).
    In a comparison of body size in a recent Miami blue population, 
females were significantly larger than males, and individuals sampled 
in the wet season were also significantly larger than in the dry season 
(Saarinen 2009, p. 43). In a comparison of recent Bahia Honda State 
Park (BHSP) individuals with specimens from historical collections 
(FLMNH data), BHSP individuals were significantly larger than 
historical specimens, females from BHSP were significantly larger than 
historical female specimens, and BHSP adults measured in wet seasons 
were larger than those sampled in wet seasons in museum collections 
(Saarinen 2009, p. 43). Saarinen (2009, p. 47) suggested that perhaps 
larger adults were selected for over time with larger adults being more 
capable of dispersing and finding food and mates. Limited food 
resources during larval development or abrupt termination of 
availability of food in the last larval instar can lead to early 
pupation and a smaller adult size (T.C. Emmel, pers. comm., as cited in 
Saarinen 2009, p. 47). It is possible that differences in host plant 
(e.g., nutrition) and age of specimens (e.g., freshness) may also be 
factors when comparing body size between recent specimens and those 
from historical collections.

Taxonomy

    The Miami blue belongs to the family Lycaenidae (Leach), subfamily 
Polyommatinae (Swainson). The species Hemiargus thomasi was originally 
described by Clench (1941, pp. 407-408), and the subspecies Hemiargus 
thomasi bethunebakeri was first described by Comstock and Huntington 
(1943, p. 97). Although some authors continue to use Hemiargus, Nabokov 
(1945, p. 14) instituted Cyclargus for some species, which has been 
supported by more recent research (Johnson and Balint 1995, pp. 1-3, 8-
11, 13; Calhoun et al. 2002, p. 13; K. Johnson, Florida State 
Collection of Arthropods, in litt. 2002). There are differences in the 
internal genitalic structures of the genera Hemiargus and Cyclargus 
(Johnson and Balint 1995, pp. 2-3, 11; K. Johnson, in litt. 2002). Kurt 
Johnson (in litt. 2002), who has published most of the existing 
literature since 1950 on the blue butterflies of the tribe 
Polyommatini, reaffirmed that thomasi belongs in the genus Cyclargus 
(Nabokov 1945, p. 14), not Hemiargus. Accordingly, Cyclargus thomasi 
bethunebakeri (Pelham 2008, p. 21) and its taxonomic standing is 
accepted (Integrated Taxonomic Information System 2011, p. 1).
    In 2003, questions about the taxonomic identity of Miami blues from 
BHSP were raised by a few individuals. To address these questions, the 
Service sent two pairs (male and female) of adult specimens to three 
independent taxonomists and reviewers (Dr. Jacqueline Miller, Associate 
Curator, Allyn Museum of Entomology (AME), FLMNH; Dr. Paul Opler, 
Colorado State University; and John Calhoun, Museum of Entomology, 
Florida State Collection of Arthropods) for verification. To avoid harm 
to the wild population, scientists examined moribund adults from a 
captive colony generated from individuals taken from BHSP. Each 
reviewer independently confirmed through various means (e.g., 
comparison with confirmed specimens, dissection and examination of 
genitalia) that the identities of the adult specimens examined were 
Cyclargus thomasi bethunebakeri (J. Miller, in litt. 2003; P. Opler, in 
litt. 2003; J. Calhoun, in litt. 2003a). We received an additional 
confirmation from Lee Miller, Curator (AME, FLMNH), stating that the 
identities of the adult specimens examined were Cyclargus thomasi 
bethunebakeri (L. Miller, in litt. 2003). Taxonomic verification by 
genitalic dissection of the Miami blue at Key West National Wildlife 
Refuge (KWNWR) has not occurred, but preliminary molecular evidence has 
confirmed that they are the same taxon (E.V. Saarinen, unpub. data, as 
cited in

[[Page 20950]]

Saarinen 2009, p. 18; E. Saarinen, in litt. 2011).

Life History

    Like all butterflies, the Miami blue undergoes complete 
metamorphosis, with four life stages (egg, caterpillar or larva, pupa 
or chrysalis, and adult). The generation time is approximately 30-40 
days (Carroll and Loye 2006, p. 19; Saarinen 2009, pp. 22, 76) and 
similar for both males and females (Trager and Daniels 2011, p. 35). 
Although a single Miami blue female can lay 300 eggs, high mortality 
may occur in the immature larval stages prior to adulthood (T. Emmel, 
University of Florida [UF], pers. comm. 2002). Trager and Daniels 
(2011, p. 40) indicated that larger, longer-lived females demonstrate a 
higher fecundity. Reported host plants are blackbead (Pithecellobium 
spp.), nickerbean (Caesalpinia spp.), balloonvine (Cardiospermum spp.), 
and presumably Acacia spp. (Kimball 1965, p. 49; Lenczewski 1980, p. 
47; Pyle 1981, p. 489; Opler and Krizek 1984, p. 113; Minno and Emmel 
1993, p. 134; Calhoun et al. 2002, p. 18; Cannon et al. 2010, p. 851). 
In addition, Rutkowski (1971, p. 137) observed a female laying one egg 
just above the lateral bud on snowberry (Chiococca alba). Eggs are laid 
singly near the base of young pods or just above the lateral buds of 
balloonvine and the flowers of leguminous trees (Opler and Krizek 1984, 
p. 113; Minno and Emmel 1993, p. 134); flower buds and young tender 
leaves of legumes are preferred laying sites (Minno and Minno 2009, p. 
78; M. Minno, pers. comm. 2010).
    On nickerbean plants (Caesalpinia spp.), females lay eggs on 
developing shoots, foliage, and flower buds (Saarinen 2009, p. 22; 
Trager and Daniels 2011, p. 35). Oviposition occurs throughout the day 
with females often seeking terminal growth close to the ground (<3.3 
feet [<1 meter]) or in locations sheltered from the wind (Emmel and 
Daniels 2004, p. 13). Eggs are generally laid singly, but may be 
clustered on developing leaves, shoot tips, and flower buds (Saarinen 
2009, p. 22). After several days of development, larvae chew out of 
eggs and develop through four instar stages, with total larval 
development time lasting 3 to 4 weeks, depending upon temperature and 
humidity (Saarinen 2009, p. 22). Fourth instar larvae pupate in 
sheltered or inconspicuous areas, often underneath leaf whorls or 
bracts (Saarinen 2009, p. 22). Adult butterflies eclose (emerge) after 
5 to 8 days, depending on temperature and humidity (Saarinen 2009, p. 
22).
    On blackbead plants, females lay eggs on flower buds and emerging 
leaves (Cannon et al. 2010, p. 851; Trager and Daniels 2011, p. 35). 
Oviposition on, or larval consumption of, mature blackbead leaves was 
not observed (Cannon et al. 2010, p. 851). Thus, Cannon et al. (2010, 
p. 851) suggested that abundance may be limited by the availability of 
young blackbead leaves and buds for egg-laying, even if abundant 
suitable nectar sources (see Habitat) are available year-round.
    On balloonvine, females lay single eggs near fruit (capsules) 
(Carroll and Loye 2006, p. 18). Newly hatched larvae chew distinctive 
holes through the outer walls of the capsules to access seeds (Minno 
and Emmel 1993, p. 134). After consuming seeds within the natal 
capsule, larvae must crawl to a sequence of two or three balloons 
before growing large enough to pupate. Attending ants follow through 
the same holes (see Interspecific relationships below). Miami blues 
were also observed to commonly pupate within mature capsules (sometimes 
with ants in attendance within the capsule) (Carroll and Loye 2006, p. 
20).
    The Miami blue has been described as having multiple, overlapping 
broods year-round (Pyle 1981, p. 489). Adults can be found every month 
of the year (Opler and Krizek 1984, pp. 112-113; Minno and Emmel 1993, 
p. 135; 1994, p. 647; Emmel and Daniels 2004, p. 9; Saarinen 2009, p. 
22). Opler and Krizek (1984, pp. 112-113) indicated one long winter 
generation from December to April, during which time the adults are 
probably in reproductive diapause (a period in which growth, 
development, and physiological activity is suspended or diminished); a 
succession of shorter generations was thought to occur from May through 
November, the exact number of which is unknown. Glassberg et al. (2000, 
p. 79) described the Miami blue as having occurred all year, with three 
or more broods. Researchers have noted a marked decrease of adults from 
December to early February at BHSP, indicative of a short diapause 
(Emmel and Daniels 2003, p. 3; 2004, p. 9). Saarinen also noted that 
the life cycle at BHSP slowed in winter months and suspected a slight 
diapause (E.V. Saarinen and J.C. Daniels, unpub. data, as cited in 
Saarinen 2009, p. 22). Conversely, Minno (pers. comm. 2010) noted that 
there have been records of adults in December and January and suggested 
that this tropical butterfly may not have a winter diapause, but 
rather, emergence may be delayed by cold temperatures in some years. 
Salvato and Salvato (2007, p. 163) and Cannon et al. (2010, pp. 849-
850) also reported numerous adults at BHSP and KWNWR, respectively, 
during winter months.
    Information on adult lifespan is limited. Based on field studies, 
adult Miami blues have been found to live 9 days, but most adults are 
thought to live only a few days (J. Daniels, UF, pers. comm. 2003a, 
2003b). In general, adults may survive less than a week in the wild; 
there are approximately 8-10 generations per year (Saarinen et al. 
2009a, p. 31). Generations are not completely discrete due to the 
variance in development time of all life stages (Saarinen et al. 2009a, 
p. 31). Adult longevity is not well understood. Some lycaenids have the 
ability to survive longer than mark-recapture studies indicate (Johnson 
et al. 2011, p. 8). For example, the Palos Verdes blue (Glaucopsyche 
lygdamus palosverdesensis), thought to live 10 days or less in the 
field, has been documented to have a life span of up to 38 days in the 
laboratory (T. Longcore, University of California, in litt. 2011; 
Johnson et al. 2011, p. 8). Additional field studies are needed to 
better ascertain adult Miami blue longevity in the wild.
    Range size and dispersal--At this time, it is unclear how far adult 
Miami blues can disperse and the mechanisms for dispersal (i.e., active 
[flight] or passive [wind-assisted]). Initial mark-recapture studies of 
the butterfly indicate they are nonmigratory and appear to be sedentary 
(Emmel and Daniels 2004, p. 6). Based on mark-recapture work conducted 
in 2002-2003, recaptured adults (N=39) moved an average of 6.53 +/-
11.68 feet (2.0 +/-3.6 meters), four individuals moved between 25 and 
50 feet (7.6 and 15.2 meters), and only three individuals moved more 
than 50 feet (15.2 meters) over a few days (Emmel and Daniels 2004, pp. 
6, 32-38). Few individuals were found to move between the lower and 
upper walkway locations of the south end colony sites at BHSP 
(approximately 100 feet [30.5 meters]); no movement between any of the 
smaller individual, isolated colony sites was recorded (Emmel and 
Daniels 2004, p. 6). However, Saarinen (2009, pp. 73, 78-79) found that 
genetic exchange between colonies occurred at BHSP and noted that small 
habitat patches may be crucial in providing links between 
subpopulations in an area.
    Interspecific relationships--As in many lycaenids worldwide (Pierce 
et al. 2002, p. 734), Miami blue larvae associate with ants (Emmel 
1991, p. 13; Minno and Emmel 1993, p. 135; Carroll and Loye 2006, pp. 
19-20; Trager and Daniels 2011, p. 35) in at least four

[[Page 20951]]

genera of ants in three subfamilies of Formicidae (Saarinen and Daniels 
2006, p. 71; Saarinen 2009, pp. 131, 133). Miami blues using nickerbean 
at BHSP and Everglades National Park (ENP) (reintroduced individuals) 
were variously tended by Camponotus floridanus, C. planatus, 
Crematogaster ashmeadi, Forelius pruinosus, and Tapinoma melanocephalum 
(Saarinen and Daniels 2006, p. 71; Saarinen 2009, pp. 131, 138). C. 
floridanus was the primary ant symbiont, commonly found tending larvae; 
other ant species were encountered less often (Saarinen and Daniels 
2006, p. 70; Saarinen 2009, pp. 131-132). Liquid (honeydew) exuded from 
the butterfly's dorsal nectary organ (honey gland) was actively imbibed 
by all species of ants (Saarinen and Daniels 2006, p. 70; Saarinen 
2009, p. 132).
    Late Miami blue instars were always found in association with ants, 
but early instars, prepupae, and pupae were frequently found without 
ants present (Saarinen and Daniels 2006, p. 70). Forelius pruinosus and 
Tapinoma melanocephalum were observed to derive honeydew from Miami 
blues they tended, but were not observed to actively protect them from 
any predator (Saarinen and Daniels 2006, p. 71; Saarinen 2009, p. 133). 
However, the presence of ants in the vicinity of larvae may potentially 
deter predators (Saarinen and Daniels 2006, pp. 71, 73; Saarinen 2009, 
p. 133; Trager and Daniels 2009, p. 480). Two additional ants, 
Paratrechina longicornis and P. bourbonica, have been identified as 
potential associates of the Miami blue (Saarinen and Daniels 2006, pp. 
70-71; Saarinen 2009, pp. 131, 138). P. longicornis was found near 
Miami blue larvae and appeared to tend them during brief encounters; P. 
bourbonica tended another lycaenid, martial scrub-hairstreak (Strymon 
martialis) at BHSP (Saarinen and Daniels 2006, p. 70). Cannon et al. 
(2007, p. 16) also observed two ant species attending Miami blues on 
KWNWR. Based on photographs, the ants appeared to be Camponotus 
inaequalis and P. longicornis. C. planatus was observed on blackbead.
    In the 1980s, Miami blue larvae that fed on balloonvine in the 
upper Keys were also tended by ants (Camponotus floridanus and C. 
planatus) (Carroll and Loye 2006, pp. 19-20). Carroll and Loye (2006, 
p. 20) found that Camponotus spp. raised with Miami blue larvae lived 
longer than ants raised with larvae of other lycaenid species or 
without any food source, demonstrating that larval secretions benefit 
ants.
    More recently, Trager and Daniels (2009, p. 479) most commonly 
found Camponotus floridanus and C. planatus associated with wild and 
recently released Miami blue larvae. In a comparison of Miami blue 
larvae raised with and without ants, no effect of ant presence was 
found on any measurements of larval performance (e.g., age at pupation, 
pupal mass, length of pupation, total time as an immature) (Trager and 
Daniels 2009, p. 480). Miami blue larval development was found to be 
similar to that of other conspecific lycaenid species not tended by 
ants (Trager and Daniels 2009, p. 480). Although the relationships are 
not completely understood, it appears that Miami blue larvae may 
receive some benefits from tending ants (e.g., potential defense from 
predators) without much, if any, costs incurred.

Habitat

    The Miami blue is a coastal butterfly reported to occur in openings 
and around the edges of hardwood hammocks (forest habitats 
characterized by broad-leaved evergreens), and in other communities 
adjacent to the coast that are prone to frequent natural disturbances 
(e.g., coastal berm hammocks, dunes, and scrub) (Opler and Krizek 1984, 
p. 112; Minno and Emmel 1994, p. 647; Emmel and Daniels 2004, p. 12). 
It also has been reported to use tropical pinelands (Minno and Emmel 
1993, p. 134) and open sunny areas along trails (Pyle 1981, p. 489). In 
the Keys, it was most abundant near disturbed hammocks where weedy 
flowers provided nectar (Minno and Emmel 1994, p. 647). It also 
occurred in pine rocklands (fire-dependent slash pine community with 
palms and a grassy understory) on Big Pine Key (Minno and Emmel 1993, 
p. 134; Calhoun et al. 2002, p. 18) and elsewhere in Monroe and Miami-
Dade Counties. In Miami-Dade County, it occurred locally inland, 
sometimes in abundance (M. Minno, pers. comm. 2010). Within KWNWR, all 
occupied areas had coastal strands and dunes fronted by beaches (Cannon 
et al. 2007, p. 13; Cannon et al. 2010, p. 851).
    Larval host plants include blackbead, nickerbean, balloonvine, and 
presumably Acacia spp. (Dyar 1900, pp. 448-449, Kimball 1965, p. 49; 
Lenczewski 1980, p. 47; Pyle 1981, p. 489; Calhoun et al. 2002, p. 18). 
Gray nickerbean (Caesalpinia bonduc) is widespread and common in 
coastal south Florida. Following disturbances, it can dominate large 
areas (K. Bradley, The Institute for Regional Conservation [IRC], pers. 
comm. 2002). Gray nickerbean has been recorded as far north as Volusia 
County on the east coast, matching the historical range of the Miami 
blue, and Levy County on the west coast (J. Calhoun, pers. comm. 
2003b). The Miami blue is also reported to use peacock flower 
(Caesalpinia pulcherrima) (Matteson 1930, pp. 13-14; Calhoun et al. 
2002, p. 18), a widely cultivated exotic that occurs in disturbed 
uplands and gardens (Gann et al. 2001-2012, p. 1). Rutkowski (1971, p. 
137) and Opler and Krizek (1984, p. 113) reported the use of snowberry. 
Brewer (1982, p. 22) reported the use of cat's paw blackbead 
(Pithecellobium unguis-cati) on Sanibel Island in Lee County.
    Prior to the 1970s, documented host plants for the butterfly were 
nickerbean and blackbead (J. Calhoun, pers. comm. 2003b). Balloonvine 
(Cardiospermum spp.) was not reported as a host plant until the 1970s, 
when these plants seemed to have become common in extreme southern 
Florida (J. Calhoun, pers. comm. 2003b). Subsequently, balloonvine 
(Cardiospermum halicacabum), an exotic species in Florida, was the most 
frequently reported host plant for Miami blue (e.g., Lenczewski 1980, 
p. 47; Opler and Krizek 1984, p. 113; Minno and Emmel 1993, p. 134; 
1994, p. 647; Calhoun et al. 2002, p. 18). However, Carroll and Loye 
(2006, pp. 13-15) corrected ``the common view that a principal host 
plant, balloonvine, is an exotic weed.'' They found that published 
reports of Miami blue larvae on balloonvine all identified the host as 
C. halicacabum and stated that the butterfly was instead dependent upon 
a declining native, C. corindum (Carroll and Loye 2006, pp. 14, 23). 
Bradley (pers. comm. 2002) also confirmed that C. halicacabum does not 
occur in the Keys, noting that the native balloonvine (C. corindum) is 
relatively common and widespread in the Keys and has been commonly 
mistaken as C. halicacabum in the Keys and other sites in south 
Florida.
    Calhoun (pers. comm. 2003b) suggested that the Miami blue may 
simply utilize whatever acceptable hosts are available under suitable 
conditions. According to Calhoun (pers. comm. 2003b), a review of the 
historical range of the butterfly and its host plants suggests 
balloonvine was a more recent larval host plant and temporarily 
surpassed nickerbean as the primary host plant. As native coastal 
habitats were destroyed, balloonvine readily invaded disturbed 
environments, and the Miami blue used what was most commonly available. 
Minno (pers. comm. 2010) suggested that the Miami blue used balloonvine 
on Key Largo and Plantation Key extensively in the 1970s through the 
1990s, noting that nickerbean, blackbead, and perhaps

[[Page 20952]]

other hosts were also probably used, but not documented.
    The Miami blue metapopulation (series of small populations that 
have some level of interaction) at KWNWR was found to rely upon Florida 
Keys blackbead as the singular host plant (Cannon et al. 2007, p. 1; 
Cannon et al. 2010, pp. 851-852). Blackbead was also an important 
nectar plant when in flower. High counts of Miami blues at KWNWR were 
generally associated with the emergence of flowers and new leaves on 
blackbead (Cannon et al. 2007, pp. 14-15; Cannon et al. 2010, pp. 851-
852). All sites that supported Miami blues contained blackbead (Cannon 
et al. 2007, p. 6; Cannon et al. 2010, p. 851). Limited abundance of 
blackbead within select areas of KWNWR was thought to limit abundance 
of the Miami blue (Cannon et al. 2007, p. 10; Cannon et al. 2010, p. 
850). At BHSP, the Miami blue was closely associated with gray 
nickerbean, but also used blackbead (M. Minno, pers. comm. 2010). In 
KWNWR, gray nickerbean was rare, with only a few small plants on Boca 
Grande Key and the Marquesas Keys (Cannon et al. 2010, p. 851).
    Adult Miami blues have been reported to feed on a wide variety of 
nectar sources, including Spanish needles (Bidens alba), Leavenworth's 
tickseed (Coreopsis leavenworthi), scorpionstail (Heliotropium 
angiospermum), turkey tangle fogfruit or capeweed (Lippia nodiflora), 
buttonsage (Lantana involucrata), snow squarestem (Melanthera nivea [M. 
aspera]), blackbead, Brazilian pepper (Schinus terebinthifolius), false 
buttonweed (Spermacoce spp.), and seaside heliotrope (Heliotropium 
curassavicum) (Pyle 1981, p. 489; Opler and Krizek 1984, p. 113; Minno 
and Emmel 1993, p. 135; Emmel and Daniels 2004, p. 12). Emmel and 
Daniels (2004, p. 12) reported that the Miami blue uses a variety of 
flowering plant species in the Boraginaceae, Asteraceae, Fabaceae, 
Polygonaceae, and Verbenaceae families for nectar. Cannon et al. (2010, 
p. 851) found the butterfly uses nine plant species as nectar sources 
within KWNWR, including: blackbead, snow squarestem, coastal searocket 
(Cakile lanceolata), black torch (Erithalis fruticosa), yellow joyweed 
(Alternanthera flavescens), bay cedar (Suriana maritime), sea lavender 
(Argusia gnaphalodes), seaside heliotrope, and sea purslane (Sesuvium 
portulacastrum).
    Nectar sources must be near potential host plants since the 
butterflies are presumably sedentary and may not travel between patches 
of host and nectar sources (Emmel and Daniels 2004, p. 13). This may 
help explain the absence of the Miami blue from areas in which host 
plants are abundant and nectar sources are limited (J. Calhoun, pers. 
comm. 2003b). Emmel and Daniels (2004, p. 13) argued that it is 
potentially critical that sufficient available adult nectar sources be 
directly adjacent to host patches and also important that a range of 
potential nectar sources be available in the event one plant species 
goes out of flower or is adversely impacted by environmental factors. 
Cannon et al. (2010, p. 851) suggested that the growth stage of 
blackbead, coupled with abundant nectar from herbaceous plants, likely 
influenced Miami blue abundance; the highest counts occurred when 
blackbead was flowering profusely and producing new leaves.

Historical Distribution

    The Miami blue butterfly (Cyclargus thomasi bethunebakeri) is 
endemic to Florida with additional subspecies occurring in the 
Caribbean (Smith et al. 1994, p. 129; Hernandez 2004, p. 100; Saarinen 
2009, pp. 18-19, 28). Field guides and other sources differ as to 
whether C. thomasi bethunebakeri occurs in the Bahamas. Clench (1963, 
p. 250), who collected butterflies in the West Indies, indicated that 
the subspecies occurred only in Florida. Riley (1975, p. 110) and 
Calhoun et al. (2002, p. 13) indicated that the Miami blue of Florida 
rarely occurs as a stray in the Bahamas. Minno and Emmel (1993, p. 134; 
1994, p. 647) and Calhoun (1997, p. 46) considered the Miami blue to 
occur only in Florida (endemic to Florida, with other subspecies found 
in the Bahamas and Greater Antilles). Smith et al. (1994, p. 129) 
indicated that the Miami blue occurs in southern Florida, but noted it 
has been recorded from the Bimini Islands in the Bahamas. However, in a 
recent comprehensive study of museum specimens, Saarinen (2009, p. 28) 
found no specimens in current museum holdings to verify this. Overall, 
the majority of historical records pertaining to this subspecies' 
distribution are dominated by Florida occurrences, with any peripheral 
occurrences in the Bahamas possibly being ephemeral in nature.
    Although information on distribution is somewhat limited, it is 
clear that the historical range of the Miami blue has been 
significantly reduced. The type series (i.e., the original set of 
specimens on which the description of the species is based) contains 
specimens ranging from Key West up the east coast to Volusia County 
(Comstock and Huntington 1943, p. 98; J. Calhoun, pers. comm., 2003b). 
Opler and Krizek (1984, p. 112) showed its historical range as being 
approximately from Tampa Bay and Cape Canaveral southward along the 
coasts and through the Keys. It has also been collected in the Dry 
Tortugas (Forbes 1941, pp. 147-148; Kimball 1965, p. 49; Glassberg and 
Salvato 2000, p. 2). Lenczewski (1980, p. 47) noted that it was 
reported as extremely common in the Miami area in the 1930s and 1940s. 
Calhoun et al. (2002, p. 17) placed the historical limits of the 
subspecies' northern distribution at Hillsborough and Volusia Counties, 
extending southward along the coasts to the Marquesas Keys (west of Key 
West).
    The Miami blue was most common on the southern mainland and the 
Keys, especially Key Largo and Big Pine Key (Calhoun et al. 2002, p. 
17) and other larger keys with hardwood hammock (Monroe County) (M. 
Minno, pers. comm. 2010). The subspecies was recorded on at least 10 
islands of the Keys (Adams Key, Big Pine Key, Elliott Key, Geiger Key, 
Key Largo, Lignumvitae Key, Old Rhodes Key, Plantation Key, Stock 
Island, Sugarloaf Key) (Minno and Emmel 1993, p. 134). On the Gulf 
coast, it was reportedly more localized and tended to occur on more 
southerly barrier islands (J. Calhoun, pers. comm. 2003b). According to 
Calhoun et al. (2002, p. 17), the Miami blue occupied areas on the 
barrier islands of Sanibel, Marco, and Chokoloskee, along the west 
coast into the 1980s (based upon Brewer 1982, p. 22; Minno and Emmel 
1994, pp. 647-648). Lenczewski (1980, p. 47) reported that the Miami 
blue historically occurred at Chokoloskee, Royal Palm (Miami-Dade 
County), and Flamingo (Monroe County) within ENP, but that the 
subspecies has not been observed in ENP since 1972.
    Based upon examination of specimens from museum collections (N = 
689), Saarinen (2009, pp. 42, 55-57) found a large, primarily coastal, 
geographic distribution for the butterfly. Most specimens from an 11-
county area from 1900 to 1990 were collected in Miami-Dade and Monroe 
Counties (Saarinen 2009, pp. 42, 58). Records from Miami-Dade County (N 
= 212) were most numerous in the 1930s and 1940s; records from Monroe 
County (N = 387) (including all of the Florida Keys) were most numerous 
in the 1970s (Saarinen 2009, pp. 42, 58). Saarinen (2009, p. 47) was 
not able to quantify issues of collector bias and noted that collecting 
restrictions, inaccessibility of certain islands, and targeted interest 
in certain areas may have been factors influencing the relative 
abundance (and distribution) of specimens collected. For example, it is 
unclear whether Key

[[Page 20953]]

Largo represented a ``central hotspot,'' a spot simply heavily visited 
by lepidopterists, or both (Saarinen 2009, p. 47). Still, it is clear 
that specimens were common in museum collections from the early 1900s 
to the 1980s, suggesting that the butterfly was abundant, at least in 
local patches, during this time period (Saarinen 2009, p. 46). This is 
consistent with the work of Carroll and Loye (2006, pp. 15-18), who, in 
a compilation of location data for specimens (N = 209), found that most 
collections were from the Upper Keys; those from peripheral sites were 
generally less recent and only single specimens. Examination of museum 
records further verified the Miami blue's wide distribution in southern 
Florida through time (Carroll and Loye 2006, pp. 15-18; Saarinen 2009, 
p. 46).
    By the 1990s, very few Miami blue populations were known to 
persist, and the butterfly had not been seen on the western Florida 
coast since 1990, where it was last recorded on Sanibel Island (Calhoun 
et al. 2002, p. 17). One of the few verifiable reports (prior to 
rediscovery in 1999) was on Big Pine Key in March 1992 (Glassberg et 
al. 2000, p. 79; Glassberg and Salvato 2000, p. 1; Calhoun et al. 2002, 
p. 17). Following Hurricane Andrew in 1992, there were a few 
unsupported reports from Key Largo and Big Pine Key and the 
southeastern Florida mainland from approximately 1993 to 1998 
(Glassberg and Salvato 2000, p. 3; Calhoun et al. 2002, p. 17). In 
1996, four adult Miami blues were observed in the area of Dagny Johnson 
Key Largo Hammock Botanical State Park (DJSP) by Linda and Byrum Cooper 
(L. Cooper, listowner of LEPSrUS Web site, pers. comm. 2002; Calhoun et 
al. 2002, p. 17). However, a habitat restoration project apparently 
eradicated that population (L. Cooper, pers. comm. as cited in Calhoun 
et al. 2002, p. 17).
    The Miami blue was presumed to be extirpated until its rediscovery 
in 1999 by Jane Ruffin, who observed approximately 50 individuals at a 
site in the lower Keys (Bahia Honda) (Ruffin and Glassberg 2000, p. 3; 
Calhoun et al. 2002, p. 17). Additional individuals were located at a 
site within 0.5 mile (mi) (0.8 kilometers (km)) of where Ruffin had 
discovered the population (Glassberg and Salvato 2000, p. 3). Glassberg 
and Salvato (2000, p. 1) stated that more than 15 highly competent 
butterfly enthusiasts had failed to find any populations of the Miami 
blue from 1992 until 1999, despite more than 1,000 hours of search 
effort in all sites known to harbor former colonies and other potential 
sites throughout south Florida and the Keys. In May 2001, there was an 
additional sighting by Richard Gillmore of a single Miami blue in the 
hammocks in North Key Largo (Calhoun et al. 2002, p. 17; J. Calhoun, 
pers. comm. 2003b).

Current Distribution

    Numerous searches for the Miami blue have occurred in the past 
decade by various parties. The Miami blue was not observed on 105 
survey dates at 11 locations on the southern Florida mainland from 1990 
to 2002 (Edwards and Glassberg 2002, p. 4). In the Keys, surveys during 
the same time period also produced no sightings of the Miami blue at 29 
locations for 224 survey dates (Edwards and Glassberg 2002, p. 4). In 
2002, the Service initiated a status survey, contracting researchers at 
the UF, to search areas within the subspecies' historical range, 
concentrating on the extreme south Florida mainland and throughout the 
Keys. Despite surveys at 45 sites during 2002-2003, adults or immature 
stages were found only at a single site near BHSP on West Summerland 
Key (Emmel and Daniels 2004, pp. 3-6; 21-25) (approximately 1.9 mi [3 
km]) west of BHSP). The Miami blue was not found on the mainland, 
including Fakahatchee Strand, Charles Deering Estate, ENP, Marco 
Island, or Chokoloskee (Emmel and Daniels 2004, pp. 5-6, 25). It was 
also absent from the following locations in the Keys: Elliott, Old 
Rhodes, Totten, and Adams Key in Biscayne National Park (BNP) and Key 
Largo and Plantation Key in the Upper Keys; Lignumvitae, Lower 
Matecumbe, Indian, and Long Keys in the Middle Keys; and Little Duck, 
Missouri, Ohio, No Name, Big Pine, Ramrod, Little Torch, Wahoo, Cudjoe, 
Sugarloaf, and Stock Island in the Lower Keys (Emmel and Daniels 2004, 
pp. 3-5; 21-24).
    Based upon an additional independent survey in 2002, the Miami blue 
was also not found at 18 historical locations where it had previously 
been observed or collected in Monroe, Broward, Miami-Dade, and Collier 
Counties into the 1980s (D. Fine, unpub. data, pers. comm. 2002). These 
were: Cactus Hammock (Big Pine Key), County Road (Big Pine Key), Grassy 
Key, John Pennekamp Coral Reef State Park (Key Largo), Windley Key, 
Crawl Key, Stock Island, Plantation Key, and Lower Matecumbe Key in 
Monroe County; Hugh Taylor Birch State Park and Coral Springs (2 
locations) in Broward County; Redlands, Frog City, Card Sound Road, and 
an unidentified road in Miami-Dade County; and Marco Island and 
Fakahatchee Strand State Preserve in Collier County.
    In 2003, the Service contracted the North American Butterfly 
Association (NABA) to perform systematic surveys in south Florida and 
the Keys to identify all sites at which 21 targeted butterflies, 
including the Miami blue, could be found. Despite considerable survey 
effort (i.e., 187 surveys performed), the Miami blue was not located at 
any location except BHSP (NABA 2005, pp. 1-7). In addition, the Miami 
blue was not present within the J.N. Ding Darling National Wildlife 
Refuge or on Sanibel-Captiva Conservation Foundation properties (both 
on Sanibel Island), during annual surveys conducted from 1998 to 2009 
(M. Salvato, pers. comm. 2011a). Monthly or quarterly surveys of Big 
Pine Key, conducted from 1997 to 2010, failed to locate Miami blues (M. 
Salvato, pers. comm. 2011b). Minno and Minno (2009, pp. 77, 123-193) 
failed to locate the subspecies during butterfly surveys throughout the 
Keys conducted from August 2006 to July 2009.
    Although two fourth-instar larvae were documented on West 
Summerland Key in November 2003, on unprotected land approximately 2.2 
mi (3.6 km) west of BHSP (Emmel and Daniels 2004, pp. 3, 24, 26), none 
have been seen there since. According to Daniels (pers. comm. 2003c), 
an adult (or adults) was likely blown to this key from BHSP by strong 
winds or was at least partially assisted by the wind.
    In November 2006, Miami blues were discovered on islands within 
KWNWR (Cannon et al. 2007, p. 2). This discovery was significant 
because it was a new, geographically separate population, and doubled 
the known number of metapopulations remaining (to 2). During the period 
from 1999 to 2009, the Miami blue was consistently found at BHSP 
(Ruffin and Glassberg 2000, p. 29; Edwards and Glassberg 2002, p. 9; 
Emmel and Daniels 2009, p. 4; Daniels 2009, p. 3). However, this 
population may now be extirpated. Thus, islands of KWNWR appear to 
support the only known extant population.
    Overall, the Miami blue has undergone a substantial reduction in 
its historical range, with an estimated >99 percent decline in area 
occupied (Florida Fish and Wildlife Conservation Commission [FWC] 2010, 
p. 11). In 2009, metapopulations existed at two main locations: BHSP 
and KWNWR, roughly 50 mi (80 km) apart. The metapopulation at BHSP is 
now possibly extirpated with the last adult documented in July 2010 (A. 
Edwards, Florida Atlantic University, pers. comm. 2011). It is feasible 
that additional occurrences exist in the Keys, but these may be 
ephemeral and low in

[[Page 20954]]

population number (Saarinen 2009, p. 143). In 2010, the Service funded 
an additional study with UF to search remote areas for possible 
presence; this study has not identified any new populations. The 
subspecies was not located in limited surveys conducted in the Cape 
Sable area of ENP in March 2011 (P. Halupa, pers. obs. 2011; M. Minno, 
pers. comm. 2011a) nor December 2011 (J. Daniels, pers. comm. 2011).

Bahia Honda State Park

    BHSP is a small island at the east end of the lower Keys, 
approximately 7.0 mi (11.3 km) west of Vaca Key (Marathon) and 2.0 mi 
(3.2 km) east of Big Pine Key. The amount of suitable habitat (habitat 
supporting larval host plants and adjacent adult nectar sources) within 
BHSP is approximately 1.5 acres (ac) (0.6 hectares [ha]). Of the 
suitable habitat available at BHSP, approximately 85 percent (1.3 ac 
[0.5 ha]) was occupied by the Miami blue (Emmel and Daniels 2004, p. 
12). The metapopulation comprised 13 distinct colonies, with the core 
comprising 3 or 4 colonies, located at the southwestern end (Emmel and 
Daniels 2004, pp. 6, 27). This area contained the largest contiguous 
patch of host plants, although the size was estimated to be 0.8 ac 
(0.32 ha) (Emmel and Daniels 2004, p. 12). The second largest colony 
occurred at the opposite (northeast) end of BHSP and was based solely 
on the presence of two to three small, isolated patches of nickerbean 
directly adjacent to an existing nature trail and parking area (Emmel 
and Daniels 2004, p. 6). The remaining colonies were isolated, with 
most occurring in close proximity to the main park road (Emmel and 
Daniels 2004, pp. 13, 27). Isolated colonies used very small patches of 
nickerbean (e.g., one was estimated to be 10 by 10 feet [3 by 3 
meters]) (Emmel and Daniels 2003, p. 3), often adjacent to paved roads 
(Emmel and Daniels 2004, pp. 6, 12, 27).

Key West National Wildlife Refuge

    Efforts to define the limits of the KWNWR metapopulation were 
conducted from November 2006 to July 2007 (Cannon et al. 2007, pp. 10-
11; 2010, p. 849). Miami blues were found at seven sites on five 
islands in the Marquesas Keys, approximately 18 to 23 mi (29 to 37 km) 
west of Key West, and on Boca Grande Key, approximately 12 mi (19 km) 
west of Key West (Cannon et al. 2007, pp. 1-24; 2010, pp. 847-848). The 
eight sites occupied by Miami blues ranged from approximately 0.25 to 
37.10 ac (0.1-15.0 ha) (Cannon et al. 2007, p. 6; 2010, p. 848). The 
combined amount of upland habitat of occupied sites (within KWNWR) was 
roughly 59 ac (23.8 ha) (Cannon et al. 2010, p. 848). Miami blues were 
not found on Woman Key, approximately 10.1 mi (16.2 km) west of Key 
West, or Man Key, approximately 6.8 mi (10.9 km) west of Key West; 
these sites had abundant nectar plants, but few host plants (Cannon et 
al. 2007, pp. 5, 12; 2010, pp. 848-850). In addition, the Miami blue 
was not found on six islands in the Great White Heron National Wildlife 
Refuge (GWHNWR); these sites contained limited amounts of, or were 
lacking, either host plants or nectar plants (Cannon et al. 2007, pp. 
5, 12; 2010, pp. 847, 850-851).
    In a separate study, Daniels also found four of the sites 
previously occupied within KWNWR to support the Miami blue variously 
from 2008 to 2010 (Emmel and Daniels 2008, pp. 7-10; 2009, pp. 9-13; 
Daniels 2008, pp. 1-6; Daniels 2010, pp. 3-5; J. Daniels, pers. comm. 
2010a). Survey effort, however, was limited. Some previously occupied 
islands were not searched, and no new occupied areas were identified.
    Followup presence and absence surveys by KWNWR in 2009 showed that 
the Miami blue was present on two sites in the Marquesas, but not on 
Boca Grande (P. Cannon, pers. comm. 2010a). In 2010, similar surveys 
indicated that the Miami blue was present on Boca Grande and one site 
in the Marquesas; it was still not located on Woman Key (P. Cannon, 
pers. comm. 2010b; T. Wilmers, pers. comm. 2010a). In March and April 
2011, Miami blues were still present on five of seven sites where 
previously found in KWNWR (T. Wilmers pers. comm. 2011a; Haddad and 
Wilson 2011, p. 2).

Reintroductions

    Although Miami blue butterflies were successfully reared in 
captivity, reintroductions have been unsuccessful. Since 2004, 
approximately 7,140 individuals have been released (J. Daniels, pers. 
comm. as cited in FWC 2010, p. 8). Initially, larvae were released in 
the vicinity of Flamingo at multiple locations within ENP (J. Daniels, 
pers. comm. 2012). Between August 2007 and November 2008, 
reintroduction events were carried out at BNP and DJSP 12 times 
resulting in the release of 3,553 individuals (276 adults/3,277 larvae) 
(Emmel and Daniels 2009, p. 4). Monitoring efforts have been limited; 
19 days were spent monitoring reintroduction sites (Emmel and Daniels 
2009, p. 4). To date, no evidence of colony establishment has been 
found (Emmel and Daniels 2009, p. 4). It is not clear why 
reintroductions were unsuccessful. Numerous factors may have been 
involved (e.g., predation, parasitism, insufficient host plant or 
larval sources). Due to limited resources and other constraints, 
standard protocols were not employed to help identify factors that may 
have influenced reintroduction success. Research with surrogate species 
may be helpful to better establish protocols and refine techniques for 
the Miami blue prior to future propagation and reintroduction efforts.

Population Estimates and Status

Bahia Honda State Park Metapopulation

    Prior to its apparent extirpation, the metapopulation at BHSP was 
monitored regularly from 2002 to 2009 (Emmel and Daniels 2009, p. 4). 
Pollard transects (fixed-route transects walked weekly under favorable 
weather conditions) at the south-end colony site (largest) yielded 
annual peak counts of approximately 175, 84, 112, and 132, from 2002 to 
2005 (prior to hurricanes), and 82, 81, 120, and 38, from 2006 to 2009 
(Emmel and Daniels 2009, p. 4). From October 2002 to September 2003, 
abundance estimates using mark-release-recapture (Schnabel method) 
ranged from a low of 19.7 in February 2003 to a high of 114.5 in June 
2003 (Emmel and Daniels 2004, p. 9).
    Counts ranged from 6 to 100 adults during surveys by the NABA, 
conducted from February 2004 to January 2005 (NABA 2005, unpub. data). 
Monthly (2003 to 2006) or bimonthly (2007) monitoring by Salvato (pers. 
comm. 2011c) at the south-end colony produced annual average counts of 
129, 58, 46, 6, and 8, respectively, from 2003 to 2007. Salvato (pers. 
comm. 2011c) observed 21, 10, and 0 Miami blues from 2008 to 2010, 
respectively, based on limited surveys.
    Due to the differences in methodologies and other factors, the 
above estimates cannot be compared. Although abundance of select 
butterflies may change frequently, their overall geographic 
distribution from year-to-year is often more consistent. Given that the 
Miami blue has overlapping generations and, at times, capacity for 
explosive growth, it may be useful to report population status in terms 
of occupied habitat, as has been done for other butterflies (Longcore 
et al. 2010, pp. 335-346; T. Longcore, in litt. 2011).
    In general, early (dry) season numbers were low in most years and 
were attributed to a persistent south Florida drought (Emmel and 
Daniels 2009, p. 4). Abundance trends indicated that there was a marked 
decrease in the number of

[[Page 20955]]

individuals during the winter months (November to February) (Emmel and 
Daniels 2004, p. 9; 2009, p. 4). Higher abundances during the summer 
wet season may relate to production of a large quantity of new terminal 
growth on the larval host plants (nickerbean) and availability of 
nectar sources from spring rainfall (Emmel and Daniels 2004, pp. 9-11).
    Four hurricanes affected habitat at BHSP in 2005, resulting in 
reduced abundance of Miami blue following subsequent storms that 
continued throughout 2006 (Salvato and Salvato 2007, p. 160). Although 
no quantitative measurements were taken, a significant portion of the 
nickerbean in the survey area (> 35 percent of the area of available 
habitat) was damaged by the storms; roughly 60-80 percent of the 
vegetation on the southern side of the island was visually estimated to 
have been heavily damaged, including large stands of host and nectar 
plants (Salvato and Salvato 2007, p. 156). Despite a decline in 
abundance after the hurricanes, the Miami blue had appeared to rebound 
toward pre-storm abundance by the summer months of 2007 (Salvato and 
Salvato 2007, p. 160). However, peaks remained below those found prior 
to the 2005 hurricane season (Emmel and Daniels 2009, p. 4).
    Although it is unclear when iguanas became established at BHSP, 
effects of herbivory on the host plant were apparent by late 2008 or 
early 2009 (Emmel and Daniels 2009, p. 4; Daniels 2009, p. 5; P. 
Cannon, pers. comm. 2009; A. Edwards, pers. comm. 2009; P. Hughes, 
pers. comm. 2009; M. Salvato, pers. comm. 2010a). Defoliation was 
mostly limited to the south-end colony site (Emmel and Daniels 2009, p. 
4). Cooperative eradication efforts to address this problem began in 
2009 and continue today; however, iguanas continue to impact terminal 
nickerbean growth (see Summary of Factors Affecting the Species) (Emmel 
and Daniels 2009, p. 4; Daniels 2009, p. 5; E. Kiefer, BHSP, pers. 
comm. 2011a). From 2006 through 2009, adult or immature Miami blues 
were found at several colony sites; however, one colony became 
relatively unproductive in 2005 (pre-hurricane) (Emmel and Daniels 
2009, p. 4). No Miami blues have been found at any roadway nickerbean 
patches within BHSP since 2005, prior to the advent of profound iguana 
herbivory and damages from hurricanes (Emmel and Daniels 2009, p. 4).
    The metapopulation has diminished in recent years likely due to the 
combined effects of small population size, drought, cold temperatures, 
and iguanas (see Summary of Factors Affecting the Species). In 2010, 
few Miami blues were observed at BHSP. On January 23, 2010, a 
photograph was taken of a pair of Miami blues mating (Olle 2010, p. 5). 
On February 12, 2010, a photograph was taken of a single adult (C. 
DeWitt, pers. comm. 2011). In March 2010, Daniels found one larva, but 
no adults (D. Cook, FWC, pers. comm. 2010a). In July 2010, a single 
adult was observed and photographed (A. Edwards, pers. comm. 2011). No 
Miami blue adults have been located during quarterly surveys conducted 
in 2010 by Salvato (pers. comm. 2010b, 2011c). No Miami blue 
butterflies of any life stage were subsequently seen despite frequent 
searches (D. Cook, pers. comm. 2010a; P. Cannon, pers. comm. 2010c, 
2010d, 2010e, 2010f; M. Salvato, pers. comm. 2011c, 2011d; Jim 
Duquesnel, BHSP, pers. comm. 2011a, 2011b).

Key West National Wildlife Refuge Metapopulation(s)

    The metapopulation at KWNWR yielded counts of several hundred, at 
various times, in 2006-2007. Checklist counting, a method where 
suitable habitat is initially screened to determine the presence of 
target species, was used during surveys conducted between November 2006 
and July 2007 to document the distribution and abundance of Miami blues 
(Cannon et al. 2007, p. 5; 2010, p. 848). Within the seven sites 
occupied in the Marquesas Keys, the highest counts ranged from 8 to 
521, depending upon site and sampling date (Cannon et al. 2007, p. 7; 
2010, p. 848). The highest count on Boca Grande was 441 in February 
2007 (Cannon et al. 2007, p. 7; 2010, p. 848). Highest counts occurred 
when blackbead flowered profusely and produced new leaves (Cannon et 
al. 2010, p. 851). In March and April, blackbead was observed to yield 
little new growth and no flowering, and oviposition by Miami blues was 
not observed (Cannon et al. 2007, p. 8). Partial searches on two 
islands in May and June revealed few Miami blues; little new leaf 
growth and no flowering of blackbead was observed at these locations 
after February 2007 (Cannon et al. 2010, p. 850). Seasonality observed 
on KWNWR was different than that described for the BHSP metapopulation 
(above). Hurricane Wilma (October 2005) heavily damaged or killed 
blackbead stands at most sites, but it also likely enhanced foraging 
habitat, if only temporarily, on select islands within the KWNWR 
(Cannon et al. 2007, p. 10; 2010, p. 851) (see Summary of Factors 
Affecting the Species).
    Periodic surveys at KWNWR in 2008 and 2009 suggested relatively 
lower levels of abundance, based upon limited effort (Emmel and Daniels 
2008, pp. 7-10; 2009, pp. 9-13) and using different methodologies. In 
February 2008, researchers recorded 3 adults on Boca Grande and a total 
of 32 adults at two islands within the Marquesas; lack of rainfall 
resulted in very limited adult nectar sources and limited new growth of 
larval host plants (Emmel and Daniels 2008, pp. 7-8). In April 2008, 
one adult was recorded on Boca Grande; one adult was also recorded at 
another island (Emmel and Daniels 2008, p. 8). In June 2008, no adults 
were located on Boca Grande, and a total of 27 were recorded from two 
other islands (Emmel and Daniels 2008, p. 9). In August 2008, no adults 
were found at Boca Grande, and five adults were recorded at another 
island (Emmel and Daniels 2008, p. 10). In March 2009, no adults were 
recorded on Boca Grande; habitat conditions were deemed very poor, with 
limited new host growth and available nectar resources (Emmel and 
Daniels 2009, p. 12). In April 2009, researchers found a total of 22 
adults from 2 islands within the Marquesas (Emmel and Daniels 2009, p. 
13).
    Based upon limited data and observations, the Miami blue persisted 
on various islands within the KWNWR in 2010. From April through July 
2010, the Miami blue was observed on 5 of 10 dates at one location 
within the Marquesas, although in limited numbers during brief surveys 
(T. Wilmers, pers. comm. 2010b). On July 28, 2010, researchers recorded 
19 adults from 3 islands within the Marquesas, in limited surveys; 
another 25 adults were recorded on Boca Grande in less than 1 hour of 
survey work (J. Daniels, pers. comm. 2010a). On September 30, 2010, 
dozens of Miami blues were observed on Boca Grande; this may have 
represented an actual population size in the hundreds (N. Haddad, North 
Carolina State University [NCSU]), pers. comm. 2010). On November 24, 
2010, researchers positively identified 48 Miami blue adults on Boca 
Grande in less than 3 hours of surveys, noting that assessment was 
difficult due to the many hundreds or possibly thousands of cassius 
blues, which were also present (P. Cannon, pers. comm. 2010b; T. 
Wilmers, pers. comm. 2010a). In March and April 2011, researchers 
observed Miami blue adults at five sites within KWNWR in numbers 
similar to those reported above (Haddad and Wilson 2011, p. 2). In July 
2011, fewer adults were observed (P. Hughes, pers. comm. 2011a). In 
September 2011,

[[Page 20956]]

Refuge staff observed 14 adults on Boca Grande (P. Hughes, pers. comm. 
2011b). In December 2011, 88 adults were found in roughly 4 hours (P. 
Cannon, pers. comm. 2012). In January 2012, Refuge staff observed 20 
adults on Boca Grande and 14 adults at one site in the Marquesas during 
brief surveys under windy conditions (A. Morkill, pers. comm. 2012).
    At this time, both the size of the metapopulation at KWNWR and its 
dynamics are unclear. However, available data (given above) suggest 
wide fluctuations of adults within and between years and sites. The 
frequency of dispersal between islands is also not known (Cannon et al. 
2010, p. 852). Due to the distance between the Marquesas and Boca 
Grande (i.e., about 7 mi [11 km]) and the species' apparent limited 
dispersal capabilities, it is possible that two (or more) distinct 
metapopulations exist within KWNWR (J. Daniels, pers. comm. 2010b). In 
September 2010, the Service initiated a new study with researchers from 
NCSU to conduct a comprehensive examination of potential habitat within 
KWNWR and GWHNWR, quantify current distribution and habitat use, and 
develop a monitoring protocol to estimate detectability, abundance, and 
occupancy parameters.

Gene Flow and Genetic Diversity Within Contemporary Populations

    Saarinen (2009, pp. 15, 29-33, 40, 44) and Saarinen et al. (2009b, 
pp. 242-244) examined 12 polymorphic microsatellite loci (noncoding 
regions of chromosomes) to assess molecular diversity and gene flow of 
wild and captive-reared Miami blue butterflies. In addition, one of 
these microsatellite loci was successfully amplified from a subset of 
the museum specimens. Although results from historical specimens should 
be interpreted with caution (due both to small sample size and the 
single microsatellite locus), Saarinen (2009, pp. 15, 50-51) reported 
some loss of diversity in the contemporary populations, though less 
than had been expected. Even with small sample sizes, historical 
populations were significantly more diverse (with generally higher 
effective numbers of alleles and observed levels of heterozygosity) 
than BHSP; KWNWR population values were between historical values and 
BHSP values (Saarinen 2009, pp. 44-46).
    Both historical and contemporary populations showed evidence of a 
metapopulation structure with interacting subcolonies (E.V. Saarinen 
and J.C. Daniels, unpub. data as cited in Saarinen 2009, p. 49). 
However, the metapopulations at BHSP and KWNWR are separated by a 
distance of more than 43 mi (70 km). Given the Miami blue's dispersal 
capabilities (E.V. Saarinen and J.C. Daniels, unpub. data as cited in 
Saarinen 2009, p. 22), it is unlikely that they interacted. Saarinen's 
work showed no gene flow and a clear distinction between the BHSP and 
KWNWR metapopulations (Saarinen 2009, pp. 36, 74, 89) (see Summary of 
Factors Affecting the Species).
    Studies addressing molecular diversity at BHSP showed the effective 
number of alleles remained relatively constant over time, at both a 
monthly (generational) and annual scale (Saarinen 2009, pp. 71, 84). 
Allelic (gene) richness was also stable over time in BHSP, with values 
ranging from 2.988 to 3.121, when averaged across the 12 microsatellite 
loci from September 2005 to October 2006. These values were lower than 
those in KWNWR [3.790] (Saarinen 2009, p. 71). However, data showed 
that the BHSP metapopulation retained an adequate amount of genetic 
diversity to maintain the population in 2005 and 2006, despite 
perceived changes in overall population size (Saarinen 2009, p. 77). No 
significant evidence of a recent genetic bottleneck was found in the 
BHSP generations analyzed; however, there may have been a previous 
bottleneck that was undetectable with the methods used (Saarinen 2009, 
pp. 72, 85, 141).
    To explore the level of gene flow and connectivity between discrete 
habitat patches at BHSP, Saarinen (2009, pp. 64-65) conducted analyses 
at several spatial scales, analyzing BHSP as a single population (with 
no subdivision), as individual colonies occupying discrete habitat 
patches (as several groups acting in a metapopulation structure), and 
as a division of clumped colonies versus other, more spatially distant 
colonies. Analyses of microsatellite frequencies were also used to 
assess gene flow between habitat patches (Saarinen 2009, p. 72). While 
some subpopulations were well linked, others showed more division 
(Saarinen 2009, p. 73). High levels of gene flow (and relatively little 
differentiation) were apparent even between distant habitat patches on 
BHSP, and the smaller patches appeared to be important links in 
maintaining connectivity (Saarinen 2009, pp. 78, 141). Overall, gene 
flow between habitat patches on BHSP was considered crucial to 
maintaining genetic diversity and imperative for the Miami blue's long-
term persistence at this location (Saarinen 2009, p. 141).
    The metapopulation structure on KWNWR is more extensive than that 
which occurred at BHSP (Saarinen 2009, p. 49). Due to small sample 
sizes from Boca Grande, only samples from the Marquesas Keys were used 
for genetic analysis of KWNWR, and results were limited (Saarinen 2009, 
pp. 66, 72). Overall, this metapopulation was found to have higher 
genetic diversity (mean observed heterozygosity of 51 percent versus 
39.5 percent) than the BHSP population (Saarinen 2009, p. 49). Allelic 
richness (3.790 in February 2008) was also higher in KWNWR (Saarinen 
2009, pp. 71, 75). Accordingly, KWNWR is a particularly important 
source of variation to be considered for future conservation efforts 
for this taxon (Saarinen 2009, pp. 71, 75), especially now if this is 
the only extant metapopulation(s) remaining. The KWNWR metapopulation 
showed signs of a bottleneck and may support the hypothesis that it is 
a newly founded population (Saarinen 2009, pp. 76, 141). Further work 
is needed to better understand the metapopulation dynamics and genetic 
implications in this population.

Summary of Comments and Recommendations

    In the proposed rule published on August 10, 2011 (76 FR 49408), we 
requested that all interested parties submit written comments on the 
proposal by October 11, 2011. We also contacted appropriate Federal and 
State agencies, scientific experts and organizations, and other 
interested parties and invited them to comment on the proposal. 
Newspaper notices inviting general public comment were published in The 
Miami Herald, Orlando Sentinel, Tampa Tribune, The Daytona Beach News-
Journal, and the Key West Citizen on Sunday, August 21, 2011. We did 
not receive any requests for a public hearing.
    During the comment period for the proposed rule, we received 37 
comment letters (from 35 entities) directly addressing the proposed 
listing of the Miami blue butterfly with endangered status and the 
proposed listing of the cassius blue, ceraunus blue, and nickerbean 
blue butterflies as threatened under similarity of appearance. With 
regard to listing the Miami blue butterfly as endangered, 25 comments 
were in support, 2 were in opposition, and 10 were neutral. With regard 
to listing the other 3 butterflies under similarity of appearance, 4 
comments were in support, and 16 comments were in opposition. Of those 
comments in opposition, six suggested alternatives that were more 
limited in scope (e.g., applying similarity of appearance provisions to 
the Miami blue's current

[[Page 20957]]

or historical range). All substantive information provided during the 
comment period has either been incorporated directly into this final 
determination or addressed below.

Peer Review

    In accordance with our peer review policy published on July 1, 1994 
(59 FR 34270), we solicited expert opinion from 14 individuals with 
specialties that include scientific expertise with butterflies, 
particularly lycaenids, and general expertise with ecology and 
conservation. We received independent responses from eight of the peer 
reviewers. We also received two collaborative responses from State 
governmental agencies, which had been solicited as part of this 
process. We address these under Comments from the State.
    We reviewed all comments received from peer reviewers for 
substantive and new information regarding the listing of the Miami blue 
butterfly as endangered and the cassius blue, ceraunus blue, and 
nickerbean blue butterflies as threatened under similarity of 
appearance. The peer reviewers concurred with the conclusion to list 
the Miami blue butterfly as endangered and provided additional 
information, clarifications, and suggestions to improve the final rule. 
In general, the majority of peer reviewers opposed Federal listing of 
the three other butterflies due to similarity of appearance; however, 
one reviewer agreed with the original proposal, and three suggested 
applying the similarity of appearance listing only to select areas 
where the butterflies may co-occur with the Miami blue.

Peer Reviewer Comments

    (1) Comment: One peer reviewer indicated that the Miami blue 
butterfly should remain in the genus Hemiargus, as originally 
described, citing Comstock and Huntington (1943), Nabokov (1945), and 
Vila et al. (2011) as relevant taxonomic papers. The reviewer noted 
that only limited phylogenetic analyses have been conducted to 
determine if the genus Hemiargus should be split into a variety of 
additional genera, such as Cyclargus. In his view, the Miami blue is 
well characterized and easily recognized, but should continue to be 
treated as Hemiargus thomasi bethunebakeri and listed as such, rather 
than Cyclargus thomasi bethunebakeri.
    Our Response: We acknowledge that some sources continue to place 
the Miami blue in the genus Hemiargus. However, our basis for using 
Cyclargus is founded on published and unpublished literature, separate 
confirmation of specimens from independent taxonomists or reviewers, 
and other accepted taxonomic sources (see Taxonomy). We note that 
several Web sites (e.g., Butterflies of America, Catalog of the 
Butterflies of the United States and Canada, and the Integrated 
Taxonomic Information System), widely regarded as definitive sources, 
also continue to place the Miami blue as Cyclargus thomasi 
bethunebakeri. We determined that this is the most appropriate 
nomenclature because it is more widely accepted by the scientific 
community. Therefore, we have used the genus Cyclargus in this final 
rule.
    (2) Comment: Two peer reviewers and five commenters expressed 
concern over the Service's determination that critical habitat is not 
prudent, disagreed with this decision, or otherwise suggested that we 
reconsider this determination. Two commenters supported our 
determination. Comments in opposition to our not prudent determination 
were largely based on the potential benefits of designating critical 
habitat and skepticism that increased risk and harm to the Miami blue 
would occur with designation, as ample detail is already available for 
poachers to locate remaining populations.
    Our Response: We determined that designating critical habitat for 
the Miami blue is not prudent. We recognize that designation of 
critical habitat can provide benefits to listed species (see Benefits 
to the Subspecies From Critical Habitat Designation, below, as well as 
discussion later in this response); however, for the Miami blue, 
increased threats (see Increased Threat to the Subspecies by 
Designating Critical Habitat, below) outweigh the benefits (see 
Increased Threat to the Subspecies Outweighs the Benefits of Critical 
Habitat Designation, below).
    We do not dispute the arguments of the two peer reviewers and some 
commenters who suggested that industrious or unethical collectors have 
enough information to be able to locate the remaining populations. We 
acknowledge that general location information is provided within the 
rule, and more specific location information can be found through other 
sources. However, we maintain that designation of critical habitat 
would more widely publicize the potential locations of the butterfly 
and its essential habitat to poachers, collectors, vandals, and 
mischievous individuals, thereby exacerbating the already significant 
threats of collection, vandalism, disturbance, fire, and other harm 
from humans.
    One commenter, who agreed with our decision that designating 
critical habitat is not prudent, provided additional references 
(Hoekwater 1997, Kleiner 1995, O'Neill 2007) showing that individuals 
poach rare and imperiled taxa for profit, even to the point of driving 
a species to extinction in order to increase the value of individual 
specimens (Laufer 2009). We want to stress that our reasons for not 
designating critical habitat go beyond the potential increased threat 
of collection, but also involve potential associated increased risks to 
sensitive and important habitats (see also Inadvertent and Purposeful 
Impacts From Humans, below). Designation of unoccupied habitat could 
also alienate any affected private landowners and stakeholders, thus 
limiting reintroduction and recovery options (see also Response to 
Comment 24 below).
    We agree that designation of critical habitat can provide some 
benefits to listed species (e.g., a tool to restore and manage habitat 
on Federal lands, greater awareness and education by the public, 
increased cooperation by other agencies to improve habitat). With the 
Miami blue, substantial efforts at education and active conservation 
efforts from Federal, State, and local agencies are already underway, 
so potential added benefits from designation would likely be minimal.
    (3) Comment: One peer reviewer stated that the status of the Miami 
blue is grave and that extinction is a distinct possibility. Another 
peer reviewer stated that the Miami blue has an extremely high 
likelihood of becoming extinct unless active conservation measures are 
applied immediately.
    One commenter indicated that the Miami blue is one of the rarest 
butterflies in the United States and in the world. The commenter 
specifically stated that it may be the single rarest butterfly species, 
and is rarer than at least 14 species that are listed under the Act. He 
indicated that understanding spatial and population structure and 
dispersal are keys to recovery, as are restoration and reintroduction. 
Another commenter, certified by the International Union for the 
Conservation of Nature to evaluate extinction risk, stated that the 
Miami blue meets all five criteria for listing under the Act. Another 
commenter urged immediate action to address threats and the development 
of a ``functional'' recovery plan, with the assistance of experts. 
Another commenter encouraged the Service to take all possible steps to 
recover the subspecies, stressing the importance of future 
reintroductions in the best possible habitats.
    Our Response: We agree. The threats to the Miami blue pose a 
significant risk

[[Page 20958]]

to the subspecies and were the basis of our emergency determination, 
which immediately put forth conservation measures (see Available 
Conservation Measures, below). We are actively working with 
stakeholders and partners to implement additional conservation actions 
now to prevent extinction. We fully intend to actively engage others 
and implement actions that will help ensure survival and long-term 
recovery. We will work closely with scientific experts, land managers, 
stakeholders, and others to ensure that any future captive propagation 
and reintroduction efforts do not harm the wild population, and occur 
in optimal habitat to increase the likelihood of persistence.
    (4) Comment: One peer reviewer stated that the largest threat to 
the Miami blue is the small size of the single remaining 
metapopulation. He contended that, if the subspecies is to survive, the 
priority needs to be on improving the quality of existing habitats, 
enlarging breeding areas, and creating new breeding habitats, if 
possible. One commenter estimated numbers at the peak of the Miami 
blue's flight period in the hundreds, stating that conservation 
biologists agree that numbers should be many thousands to counteract 
the negative effects of inbreeding, genetic drift, and environmental 
catastrophes. This commenter also stated the small area currently 
occupied is ``frighteningly small'' and that additional and more 
widespread sites are needed to provide insurance against the extinction 
of a localized population. This reviewer and other commenters believed 
that reestablishment at other locations is a priority because of the 
substantial risk of extinction due to stochastic events and other 
threats.
    Our Response: We agree that several of the most important threats 
to the Miami blue are currently small population size, few populations, 
and restricted range. We concur that the actions specified are needed 
and acknowledge that other actions to reduce threats are also needed 
for survival and recovery (see Determination of Status, below).
    (5) Comment: One peer reviewer suggested that poaching is a more 
accurate term than collection. This reviewer viewed poaching as a 
potential threat to the Miami blue and indicated that to spend ``two 
full pages discussing hypothetical threats sounds biased'' in his view. 
One commenter stated that the Miami blue has no protection from 
poachers and suggested that listing may invite poachers to offshore 
islands. She indicated that she has been contacted by someone 
interested in acquiring rare butterflies. Another commenter noted that 
listing would call additional attention from commercial traders to the 
Miami blue and related species.
    Our Response: We provided a thorough and detailed description of 
the threat posed by collection in the proposed rule. In addition, we 
believe that it is necessary to fully discuss the many activities that 
go beyond collection, and include other illegal and illicit activities. 
Because we do not have evidence of collection of the Miami blue, we 
outline illegal and illicit activities involving other listed or 
imperiled butterflies on various protected lands and the established 
markets for specimens. We have determined that poaching is a potential 
and significant threat that could occur at any time, but poaching is 
only a subset of the activities that threaten the Miami blue. The 
generic term ``collection'' is more easily understood by the public and 
better encompasses the breadth of activities related to this threat.
    We recognize that listing may inadvertently increase the threat of 
collection and trade (i.e., raise value, create demand). However, we 
have determined, based upon the best available scientific information, 
that the subspecies meets the criteria for Federal protection. 
Accordingly, it is our obligation to take protective action through 
Federal listing to help safeguard the subspecies.
    (6) Comment: Two peer reviewers indicated that a better 
understanding of host plants will be essential for effective Miami blue 
conservation. One noted that there is considerable ambiguity as to the 
breadth of host plant use and plant-herbivore interactions. Another 
peer reviewer noted the general preference of the Palos Verdes blue 
butterfly for fresh growth on host plants (citing Johnson et al. 2011). 
This reviewer suggested that not all available host plant mass at a 
given location may be appropriate for use (larval and female egg-
laying) and that the actual available suitable host plant may be far 
less than the total mass at any given site. One commenter suggested 
that no natural populations of the Miami blue are known to feed on 
balloonvine, despite its availability. Another commenter noted that the 
Miami blue was originally associated with balloonvine, but subsequently 
adapted to using gray nickerbean due to efforts to control balloonvine.
    Our Response: We agree that further studies into historical and 
current Miami blue host plant preferences are essential to best 
conserve and recover the subspecies. Available scientific literature 
documents a variety of host plants for the Miami blue (see--Life 
History and Habitat under Background, above). This is consistent with 
recent host plant use in contemporary Miami blue populations. The last 
Miami blues observed on northern Key Largo in 1996 fed on balloonvine; 
those at BHSP fed on nickerbean and blackbead; and those within KWNWR 
rely primarily on blackbead. We note that balloonvine was not reported 
as a host plant until the 1970s, and that host plant use appears to 
have changed through time depending upon availability (see Habitat for 
complete discussion). Balloonvine was likely only one of several 
legumes used by historical Miami blue populations.
    We agree that not all available host plants at a given location may 
be appropriate for larval use and that actual available suitable host 
plant mass may be far less than the total present. This is consistent 
with findings from available research. For example, when the Miami blue 
occurred at BHSP, only a small portion of available habitat on the 
island appeared occupied, and higher abundances were found when there 
was a large quantity of new terminal growth of nickerbean and when more 
nectar sources were available (Emmel and Daniels 2004, pp. 9-12).
    (7) Comment: One peer reviewer recommended several clarifications 
regarding the description of the Miami blue (wing-chord length) and 
aspects of its life history (four instars, not five).
    Our Response: We have replaced the term ``wing-chord length'' with 
the more frequently used measure of ``forewing.'' The term fifth-instar 
was a typographical error and has been corrected with fourth-instar. We 
also made other suggested minor clarifications. These changes are set 
forth in the Background section of this final rule.
    (8) Comment: Two peer reviewers questioned the maximum adult life 
span of the Miami blue and how this was determined and suggested that 
adults likely live more than 9 days. These reviewers suggested that 
older individuals may be more likely to disperse and that finding them 
once dispersed may be difficult. One reviewer cited research showing 
that older females may be prone to longer movements (Bergman and Landin 
2002, p. 361).
    Our Response: We agree that the maximum 9-day life span as 
discussed in the emergency rule is unclear and may be an underestimate 
of natural adult life span. We have clarified the text in this final 
rule accordingly. Additional field studies are needed to

[[Page 20959]]

better ascertain adult Miami blue longevity in the wild and to 
determine dispersal capabilities.
    (9) Comment: Three peer reviewers and one commenter questioned the 
degree to which the Miami blue is sedentary, suggesting that it may be 
less sedentary than described. One reviewer suggested that the 
subspecies may be sedentary at certain stages of its life, but that the 
Miami blue's historical range (i.e., central Florida to the Keys and 
Dry Tortugas) is evidence that it disperses over wide areas of water 
over long periods of time. Another suggested that it only takes a 
wayward gravid female to colonize a new habitat. Another suggested that 
a butterfly surviving in a metapopulation due to habitat structure such 
as the Miami blue must have stronger dispersal capabilities than 
described in the rule, at least in a small fraction of the population.
    One commenter stated that, although the butterfly appears to be 
sedentary now, it once occurred widely in the Keys and coastal areas of 
central and southern Florida and that it is capable of dispersing and 
colonizing new areas, including islands.
    Commenters suggested that keys to designing a recovery strategy 
include a clear focus on basic life history, population dynamics, and 
an improved understanding of dispersal. One commenter indicated that a 
well-informed recovery plan would include a strategy for multiple 
interconnected populations that buffer the subspecies when some 
localized populations are lost and that more information is needed 
about dispersal capacity.
    Our Response: We agree that the Miami blue may be less sedentary 
than described and have made clarifications to the text. At this time, 
it is unclear how far the butterfly can disperse and the mechanisms for 
dispersal (i.e., active [flight] or passive [wind-assisted]). We 
acknowledge that wayward individuals and gravid females can colonize 
new areas. Clearly, additional study is needed to better understand the 
Miami blue's dispersal capabilities and mechanisms. We agree that 
improved understanding of basic life history and population dynamics, 
including dispersal, will be key components to an effective recovery 
strategy. An effective recovery strategy will likely provide for 
multiple, interconnected populations that enable genetic exchange and 
facilitate recolonization in the event of local extirpations.
    (10) Comment: One peer reviewer indicated that diapause can be 
difficult to detect. He suggested that the Miami blue, like other 
closely related species, could enter diapause as third instars rather 
than as adults, in response to photoperiod, temperature, or changes in 
host plants.
    Our Response: We acknowledge that there is some uncertainty 
regarding diapause (see Life History). We believe that the Miami blue's 
life history requires further study in order to better determine if any 
life stages undergo a dormant period.
    (11) Comment: One peer reviewer expressed his opposition of mark-
recapture methods for lycaenids, particularly small blues, such as the 
Miami blue butterfly.
    Our Response: We acknowledge that not enough information is known 
about the influence of mark-recapture on butterflies and that it can be 
harmful, depending upon the species, techniques employed, skill of 
handlers, and other factors. There have been several studies of various 
mark-recapture techniques with conflicting results regarding the impact 
on butterflies. Recently, Haddad et al. (2008, p. 938) reviewed several 
types of monitoring techniques and suggested that mark-recapture is not 
appropriate for small and/or imperiled butterflies. Researchers are not 
employing mark-recapture techniques on the Miami blue at this time.
    (12) Comment: One peer reviewer indicated that disturbance factors 
may be beneficial to the host plants and that conservationists have a 
tendency to remove disturbances from protected lands, which can work 
against species dependent upon early successional plants (citing 
Longcore and Osborne 2010 and Longcore et al. 2010). One commenter 
indicated that trampling of host plants has occurred within KWNWR.
    Our Response: We agree that periodic natural disturbances may 
benefit the habitat, thereby increasing the vigor or distribution of 
important host plants. However, human-related disturbances (e.g., 
vandalism, trampling, camping, fire pits) can present significant risk 
to the Miami blue (especially larval stages) and important stands of 
host plants (see Inadvertent and Purposeful Impacts from Humans). Given 
the butterfly's overall vulnerability to extinction, we acknowledge 
that it will be important to minimize human-related and other 
controllable threats, especially in areas of known occupied habitat. 
Reducing threats will help safeguard the subspecies and its habitat.
    (13) Comment: One peer reviewer stressed the importance of ant 
associations among lycaenids and provided various examples and 
citations. This reviewer stated that he believed that carpenter ants, 
Camponotus spp., may be extremely important in the reintroduction and 
long-term survival of the Miami blue at specific locations and that 
successful establishment may be dependent upon presence of these ants. 
Another peer reviewer cited a new paper by Trager and Daniels (2011) on 
mating and egg production in the Miami blue, noting that incorporating 
that study into the background does not change the outcome or 
conclusions of the proposed and emergency rules. Two commenters also 
noted interactions (mutualistic, predatory) between the Miami blue and 
ants and suggested further investigation.
    Our Response: We agree that ant associations may be an important 
component of the Miami blue's life history and that further studies of 
ant and Miami blue larval interactions are needed. Studies focusing on 
remaining populations would be useful. However, it may also be helpful 
to examine ant-larval interactions using surrogate species at 
historical Miami blue locations (e.g., BHSP or Key Largo) or in the 
laboratory. We have included information from the Trager and Daniels 
(2011) paper in the Background (see Life History, above) and agree that 
this paper does not alter the conclusions of our proposed and emergency 
rules. It also does not alter the conclusions of this final rule.
    (14) Comment: One peer reviewer cautioned against comparisons of 
Pollard transect counts with mark-recapture abundance estimates, noting 
that these two different methods of estimating population size can be 
compared with similar methods but not necessarily with each other. This 
reviewer suggested that, because the Miami blue has overlapping 
generations and presumably the capacity for explosive growth, it might 
be more productive to report population status in terms of area 
occupied (citing Longcore et al. 2010).
    Our Response: We agree. We understand that there are a variety of 
techniques to measure abundance and monitor butterfly populations and 
have clarified discussion of available data (see Population Estimates 
and Status, above). Researchers are currently refining methods and 
techniques to most effectively gauge population size within KWNWR, 
including seasonality, as part of an ongoing study the Service funded 
in 2010. Gauging overall status in terms of occupied habitat, as has 
been done for other butterflies, may be more meaningful (Longcore et 
al. 2010, pp. 335-346; T. Longcore, in litt. 2011).
    (15) Comment: One peer reviewer noted that Clench only made one 
collecting trip to the West Indies (the

[[Page 20960]]

Bahamas before 1941) (see Clench 1941).
    Our Response: We have clarified the text in this final rule 
accordingly.
    (16) Comment: One peer reviewer was concerned about a proposed 
project to develop a zip-line course at Crane Point in the City of 
Marathon and suggested that the Service work closely with the City to 
minimize potentially adverse impacts of such a development to the 
recovery of the Miami blue.
    Our Response: We were not aware of this particular project, but we 
are coordinating with agencies and partners regarding various 
development projects within Monroe County to avoid and minimize impacts 
to the Miami blue and other federally listed species. We will work 
closely with the City of Marathon and others on this potential project 
as well.
Comments Relating to Similarity of Appearance Butterflies
    (17) Comment: Six peer reviewers and ten commenters opposed listing 
the other butterflies due to similarity of appearance, as proposed, for 
a variety of reasons. The proposed action was generally opposed because 
it was thought to be overly restrictive or not needed because the 
similar butterflies are common and can be readily differentiated from 
the Miami blue based upon clear morphological differences.
    Some reviewers and commenters supported the listing of the similar 
butterflies as proposed. Other reviewers, commenters, and FWC suggested 
alternatives for application of the similarity of appearance provision 
of the Act. These alternatives consisted of limiting application to 
only areas where the butterflies are sympatric with the Miami blue 
(potential or occupied habitat), only within critical habitat (if 
designated), only within specified counties, or only within counties 
within the Miami blue's historical range.
    Those in opposition generally believed that listing similar 
butterflies would impede research and discourage cooperation or 
scientific support for future listing actions. Several commenters 
indicated that it would negatively and needlessly impact collectors, 
hobbyists, and those who collect insects for educational purposes. One 
commenter stated that there should not be any restrictions on the sale, 
purchase, or gifts of legally obtained cassius, ceraunus, or nickerbean 
blue butterflies. One commenter warned that the ``unnecessary ban on 
collection and commerce'' of the three ``similar'' species could 
ultimately harm the butterflies by impeding research and future 
discoveries, and also harm the relationships between the Service and 
hobbyist collectors, researchers, and naturalists. The same commenter 
suggested that careful monitoring and patrolling of occupied and 
historical suitable sites may be a more effective protective measure 
than enforcing a ban on collection and commercial transactions 
involving these taxa at a state or national level.
    Another commenter noted that the action was not necessary because 
those seeking to collect the Miami blue or similar species on protected 
conservation lands would theoretically already possess the necessary 
permits. Some commenters suggested that listing due to similarity of 
appearance was inconsistent with other butterfly listings that have 
similar species that more closely resemble each other and do not have 
similarity of appearance provisions.
    Our Response: We carefully considered all of the comments received 
and agree that prohibiting collection, possession, and trade of these 
similar butterflies throughout their national and international ranges 
could result in unnecessary restrictions and regulatory burdens. After 
careful review of the needs of the Miami blue and the potential impacts 
of the special 4(d) rule as originally proposed, we have reconsidered 
this aspect of the proposed rule and have made significant changes 
regarding its application. Consequently, in this final rule, only 
collection of these similar butterflies within the current and 
historical range of the Miami blue butterfly will be prohibited. See 
Summary of Changes from Proposed Rule, below, for more detail.
    We maintain that the Miami blue, due to its small population size 
and few populations, faces a significant threat from collection, and 
that prohibiting collection of similar butterflies within the 
historical range of the Miami blue is in the best interest of the 
subspecies. We have determined that limiting application of the special 
4(d) rule to only the act of collecting and only within the historical 
range of the Miami blue is sufficient to protect the subspecies from 
threats faced due to collection pressure on the three similar 
butterflies. The proposed restrictions on trade and commerce have been 
removed, thus eliminating unnecessary restrictions and reducing 
regulatory burdens for most potentially affected parties (i.e., 
elsewhere in Florida, other countries). We value relationships and are 
committed to working cooperatively with stakeholders to relieve 
unnecessary burdens while safeguarding the subspecies.
    With regard to concerns regarding research, studies can be 
conducted on the similarity of appearance butterflies in the vast 
majority of their ranges (i.e., outside of Florida, outside of the 
affected counties in Florida). For research in south and central 
Florida, many scientific activities involving the similar butterflies 
will only need prior written authorization (e.g., a letter) from the 
Service. See Special Rule Under Section 4(d) of the Act below for more 
information.
    We agree that increased patrols and monitoring may be helpful in 
deterring collection of the Miami blue. However, due to limited 
resources, this may not be feasible.
    We disagree with views that listing the other butterflies due to 
similarity of appearance is unnecessary because those seeking to 
collect the Miami blue or similar species on conservation lands would 
already possess the necessary permits. We are aware of cases where 
federally listed species have been collected from conservation lands 
illegally or without permits (see Collection, below) and acknowledge 
that listing may increase demand for specimens. We have determined that 
the similarity of appearance provisions will help deter potential 
collection of Miami blues (purposeful or inadvertent) in all areas 
within its historical range, including those areas that are not 
conserved or those in private ownership.
    Finally, we acknowledge that similarity of appearance has not been 
previously applied to arthropods (including insects, such as 
butterflies) prior to this listing, but it is a tool available to us 
under the Act. Similarity of appearance protections can be effective in 
situations where collection is a primary threat and population sizes 
are extremely low, as in the case of the Miami blue butterfly. We have 
determined that a special rule listing the additional three butterflies 
is necessary in this instance to protect the subspecies from collection 
throughout its current and historical range.
    (18) Comment: One peer reviewer indicated that, if listing creates 
demand for collectors, then listing of the other similarity of 
appearance butterflies will increase the likelihood of intentional or 
unintentional collection of the Miami blue. Another reviewer and a 
commenter suggested that listing would increase their values to 
collectors. Other reviewers and commenters believed that the issue of 
illegal collection of the Miami blue is unlikely to be deterred by 
listing the three additional co-occurring, common butterflies.

[[Page 20961]]

    Our Response: Although we agree that listing may create demand for 
some collectors, we find that prohibiting collection of the similarity 
of appearance butterflies within the Miami blue's historical range will 
help reduce the threat of collection for the Miami blue. Through this 
action, the public and all stakeholders will be aware that the 
collection of the Miami blue and other similar blue butterflies in 
coastal south and central Florida is prohibited and illegal.
    (19) Comment: One peer reviewer questioned if the other similarity 
of appearance butterflies would remain listed should the Miami blue 
butterfly become extinct.
    Our Response: If the Miami blue becomes extinct, the similarity of 
appearance butterflies will remain listed until the Miami blue becomes 
delisted, or we deem that the similarity of appearance protections are 
no longer necessary. In either of these scenarios, the Service would 
need to have adequate scientific data suggesting these actions are 
warranted, and then proceed with the normal rulemaking process (i.e., 
publish proposed and final rules in the Federal Register).

Comments From the State

    Section 4(i) of the Act states, ``the Secretary shall submit to the 
State agency a written justification for his failure to adopt 
regulations consistent with the agency's comments or petition.'' 
Comments received from the State are addressed below.
    (20) Comment: The FWC stated that it did not have any additional 
data or other information that would lead to different conclusions 
regarding the Miami blue's threats, life history, or other ecological 
attributes. The FWC supported our decision not to designate critical 
habitat. With regard to listing the other three blues as threatened due 
to similarity of appearance, the FWC supported the listing of the other 
blues, but suggested that it need only apply to the counties within the 
Miami blue's historical range. The FWC also encouraged the use of their 
management plan as a basis for the Federal recovery plan and other 
management and recovery actions.
    Our Response: We agree with the FWC's recommendation to apply 
similarity of appearance protection only in the counties within the 
Miami blue's historical range and have modified this final rule 
accordingly in response to these and other comments received. See 
Summary of Changes from Proposed Rule, below.
    We intend to draw upon the State's management plan for the Miami 
blue and all other relevant sources during recovery planning and 
implementation efforts. We will be soliciting input from the State and 
other stakeholders, who are integral in the conservation of the 
subspecies, during recovery planning.
    (21) Comment: The Florida Department of Environmental Protection 
(FDEP) found the proposed rule to be comprehensive and suggested no 
changes. The FDEP noted the thorough evaluation of research by Zhong et 
al. (2010), which demonstrated that a single treatment within normal 
mosquito control operations can kill substantial Miami blue larvae in 
targeted residential areas and, to a lesser extent, in adjacent 
nontarget areas. The FDEP suggested this research may indicate that 
normal mosquito control operations may have played a role in the 
historical decline of the Miami blue and other Keys insect fauna. The 
FDEP recommended that research be continued to better understand the 
impacts of mosquito control and exotic fire ants.
    Our Response: We agree that additional research will be helpful in 
developing a more thorough understanding of impacts from mosquito 
control, fire ants, and other threats. We are interested in working 
with others to better understand and address threats.

Federal Agency Comments

    (22) Comment: The Naval Air Station Key West (NAS) expressed its 
commitment to work proactively with the Service to address potential 
issues should the Miami blue be listed as endangered. The commenter was 
concerned that, if critical habitat was designated, this would have 
significant impacts on the Navy's ability to conduct mission-essential 
activities.
    Our Response: We appreciate the Navy's assistance in the 
conservation of the Miami blue and acknowledge their concerns. We have 
worked cooperatively with the Navy regarding their Integrated Natural 
Resource Management Plan (INRMP) for NAS and realize it affords many 
provisions for successful ecosystem management and protections for 
listed species. We will coordinate with NAS to incorporate conservation 
actions for the Miami blue into their INRMP.

Public Comments

Comments Relating to Critical Habitat
    (23) Comment: Several commenters encouraged the designation of 
critical habitat, emphasizing the need and importance of such 
designation, especially for reintroduction and recovery. One commenter 
stated that there is unquestionably habitat on the Keys and in south 
Florida that is critical to the butterfly's recovery. Another commenter 
stated that critical habitat designations are required to ensure 
successful reintroductions of Miami blue populations elsewhere in its 
historical range. These commenters indicated that such designation is 
imperative for achieving recovery goals for the Miami blue and 
recommended that high-quality target areas for reintroduction be listed 
as critical habitat. One commenter suggested that designating critical 
habitat has the benefit of doubling the likelihood that an endangered 
species will recover.
    Our Response: We acknowledge that there are benefits to designating 
critical habitat, as the commenters suggest (see Benefits to the 
Subspecies From Critical Habitat Designation, below). For the Miami 
blue, we have determined that increased harm to the subspecies and its 
habitat outweighs the benefits that critical habitat may provide (see 
Increased Threat to the Subspecies by Designating Critical Habitat and 
Increased Threat to the Subspecies Outweighs the Benefits of Critical 
Habitat Designation, below).
    We disagree that designation of critical habitat is required or 
needed for successful reintroductions of the Miami blue, or that it is 
imperative for achieving recovery. Landowner permission is needed to 
reintroduce endangered species, even if unoccupied critical habitat is 
present. Some private property owners in the Keys have reportedly 
threatened to clear vegetation from undeveloped parcels to avoid 
restrictions regarding the butterfly (M. Minno, in litt. 2011b; N. 
Pakhomoff-Spencer, consultant, pers. comm. 2011). Designation of 
critical habitat would also preclude the use of nonessential 
experimental populations (NEPs) under section 10(j) of the Act, a tool 
that could be useful to help reintroduce the subspecies in select areas 
within its historical range in the future. Section 10(j)(2) of the Act 
prohibits the use of NEPs where critical habitat is designated (the two 
are mutually exclusive). Overall, we believe that successful 
reintroductions and recovery will be dependent upon improved captive 
propagation and reintroduction techniques, removal of controllable 
threats, and cooperation of landowners, stakeholders, and partners.
    Finally, with regard to the recommendation to include targeted 
high-quality reintroduction sites as critical habitat, there is 
currently no accepted, established list of high-quality reintroduction 
sites, as implied.

[[Page 20962]]

Preliminary assessments to determine the best potential reintroduction 
sites are outdated. Since originally assessed, additional populations 
of the Miami blue (using a different host plant) have been found, we 
have a better understanding of threats, and the captive colony no 
longer exists. We expect to reevaluate potential reintroduction sites 
to determine those most suitable with the help of our partners and 
prior to future captive propagation, reintroduction, and monitoring 
efforts.
    (24) Comment: Two commenters suggested that it is not feasible to 
eliminate all threats throughout the Miami blue's historical range, but 
that designating critical habitat will have the benefit of identifying 
focused management zones for persistence. One commenter suggested that 
critical habitat should provide additional benefits in that spraying 
for mosquitoes would be prohibited, host plants would be completely 
protected, and invasive species would be removed. He argued that 
without designating critical habitat there are few regulatory 
mechanisms that will mitigate illicit activities contributing to 
habitat destruction at potential reintroduction sites within the 
historical range.
    Another commenter acknowledged the value of designating critical 
habitat for conservation and management purposes and suggested that the 
limited amount of remaining vital habitat be identified for the Miami 
blue. He suggested that site assessments conducted during the 
unsuccessful reintroduction efforts could help identify this habitat. 
This commenter indicated that designating all undeveloped coastal areas 
as critical habitat is too sweeping and ignores the potential for more 
specific environmental requirements, which may help explain the failure 
of the reintroduction efforts. Additional studies to identify habitat 
requirements were recommended.
    Our Response: We agree that it is not possible to eliminate all 
threats throughout the Miami blue's historical range and acknowledge 
that designating critical habitat could help focus management actions. 
However, we determined that designation of critical habitat is not 
prudent for the Miami blue for the reasons stated below (see Critical 
Habitat and Prudency Determination and explanatory sections that 
follow).
    With regard to threats, it is not realistic to assume that critical 
habitat designation would remove threats such as mosquito-control 
pesticides, completely protect host plants, or guarantee that invasive 
species would be removed, as one commenter purports. Critical habitat 
only provides protections where there is a Federal nexus (i.e., actions 
that come under the purview of section 7 of the Act) (see Benefits to 
the Subspecies from Critical Habitat Designation, below). Mosquito 
control activities are not normally considered Federal projects, and 
would therefore not typically be subject to section 7 review. 
Furthermore, a landowner is not obligated to conduct conservation 
actions, such as the removal of invasive plants, when critical habitat 
is designated.
    We disagree with the view that there are few regulatory mechanisms 
that will mitigate activities contributing to habitat destruction 
within the subspecies' historical range. Sections 7, 9, and 10 of the 
Act (see Available Conservation Measures, below) can provide useful 
regulatory mechanisms that will help conserve the Miami blue in its 
current and historical range. In addition, listing facilitates 
proactive programs and partnerships that can help protect and restore 
habitats and implement recovery actions (e.g., section 4 and 6 of the 
Act; see Available Conservation Measures, below). In short, some 
commenters may have overestimated the potential benefits of critical 
habitat designation and underestimated the regulatory protections that 
the Act confers simply when a species is listed as endangered.
    Finally, we agree that additional studies to identify specific 
habitat requirements are needed. Such studies would be helpful to both 
understanding the Miami blue's specific physical and biological habitat 
needs and for increasing the likelihood of successful reintroductions 
in the future. These actions will likely be undertaken with researchers 
and others during recovery planning and implementation.
    (25) Comment: One commenter stated that the conditions given under 
50 CFR 424.12(a)(1) for a not prudent determination would apply to most 
endangered species, especially insects that maintain small populations. 
The commenter contended that the increased threat to the Miami blue 
from designating critical habitat would be minimal because most 
suitable habitat exists within protected State and Federal lands.
    Our Response: We disagree that a ``not prudent'' determination 
would apply to most endangered species. However, we acknowledge that it 
may often apply to endangered insects and plants that are highly sought 
after by collectors, hobbyists, and enthusiasts (e.g., butterflies, 
tiger beetles, orchids, cacti). Although we acknowledge that most 
suitable habitat for the Miami blue is on State, Federal, or other 
conservation land, we do not agree with the commenter's view that 
increased threat to the butterfly from designation would be minimal. In 
fact, we find that the increased threat may be substantial in that it 
could exacerbate the already serious threats of collection, vandalism, 
disturbance, fire, and other harm from humans (see Increased Threat to 
the Subspecies by Designating Critical Habitat, below).
    (26) Comment: Two commenters suggested that since high-quality 
target areas for reintroduction are all located on Federal, State, or 
conservation lands, there would not be significant economic consequence 
to designating critical habitat.
    Our Response: We agree that the majority of suitable and potential 
habitat for the Miami blue occurs on Federal, State, or conservation 
lands. Our determination is that critical habitat designation for the 
Miami blue is not prudent. Therefore, an economic analysis was not 
required by the Act and was not conducted.
Comments Related to Taxonomy and Current Distribution
    (27) Comment: The National Environmental and Planning Agency of 
Jamaica provided comments prepared by the Scientific Authority of 
Jamaica regarding the relative abundance and distribution of the 
cassius blue butterfly in that country. It indicated that it did not 
have data to support the suspected decline in Jamaica and had 
insufficient evidence to concur with the proposal. The agency suggested 
a population and distribution study was needed to determine 
conservation status in Jamaica.
    Our Response: We appreciate the comments provided. However, the 
proposed rule did not suggest listing the cassius blue butterfly on the 
basis of imperilment. Rather, it proposed threatened status for the 
cassius blue solely due to its similarity in appearance to the Miami 
blue, and to provide greater protection for the Miami blue. In response 
to comments received during the public comment period, the similarity 
of appearance aspect of the final rule has been modified. The Service 
no longer sees a need to list the cassius blue, ceraunus blue, or 
nickerbean blue butterflies as threatened throughout their ranges. 
Rather, we believe that prohibiting collection of these similar 
butterflies only in the historical range of the Miami blue in Florida 
is sufficient for minimizing the threat of collection of the Miami 
blue.

[[Page 20963]]

Therefore, the cassius blue will not be listed under the similarity of 
appearance provision of the Act in Jamaica (see Summary of Changes from 
Proposed Rule, below.).
    (28) Comment: Five commenters expressed concern regarding taxonomy 
and current distribution. Another commenter stated that the question of 
taxonomic status has been settled since multiple, independent 
researchers have verified the unique standing of the Miami blue by 
genitalic dissection (See also Comment 29 and Response below).
    One commenter, who had previously identified captive-reared BHSP 
specimens as Cyclargus thomasi bethunebakeri, noted limitations in 
contemporary specimens and available literature about Cyclargus taxa. 
This commenter indicated that there are morphological and genetic 
differences between historical and contemporary populations of C. 
thomasi in Florida [noting Saarinen (2009)] and suspected that these 
disparities may indicate the presence of a Cuban entity now in the 
lower Keys. However, he acknowledged that he was unaware of any 
detailed morphological or genetic investigations of the Cuban entity. 
Considering Florida's proximity to other West Indian populations, he 
suggested that it is possible that multiple genetic entities of C. 
thomasi have occurred (or do occur) in Florida, and the presence of a 
more genetically diverse metapopulation within the KWNWR may be the 
result of more recent immigrations from Cuba. Further, this commenter 
noted an unconfirmed report that captive-bred Miami blue larvae did not 
readily accept balloonvine, reinforcing his notion that historical and 
contemporary populations are not the same entity.
    Another commenter stated that the Service does not have the 
necessary information to determine if Cyclargus thomasi bethunebakeri 
is globally endangered or not since C. thomasi has recently been 
reported from Cuba and appears to be secure there. He indicated that it 
has not been determined if the entity in Cuba is different from the 
subspecies in Florida and that it is possible that these are the same 
subspecies. He also noted that C. thomasi bethunebakeri has been 
reported from the Bimini Islands in the western Bahamas. In his view, 
the entity in Cuba may be the same subspecies and it may be secure; 
therefore, the Florida taxon is not endangered, and should not be 
listed at this time.
    Another commenter noted that the Cyclargus thomasi complex was not 
well defined, citing Johnson and Balint (1995). This commenter 
recommended that the taxonomic status be clarified.
    Another commenter indicated the differences between photographs she 
had taken from BHSP with those she had discovered within KWNWR. She 
suggested the possibility that the KWNWR colonies may more closely 
resemble those of Cuba and elsewhere, rather than those from mainland 
Florida. She noted that the range of the butterfly does not seem well 
documented in recent years, and that the full range outside of the 
known locations should be determined.
    Our Response: We understand the commenters' questions and 
uncertainty regarding taxonomy and distribution. We disagree with the 
comment that the subspecies is not well defined or described. The best 
scientific and commercial information and evidence indicates that 
Cyclargus thomasi bethunebakeri is a distinct, well-described and 
examined taxon (see Taxonomy, above) and that its distribution is 
limited (see Historical Distribution and Current Distribution).
    Some concerns over the taxonomy and current distribution are based 
on discussion of a similar looking blue butterfly recently documented 
in Cuba. Historically, the nickerbean blue, Cyclargus ammon, was 
reported from Cuba. However, Hernandez (2004, p. 100) indicated that an 
undetermined subspecies of Cyclargus thomasi is now also known to occur 
on the island. Craves (2004, p. 43) indicated that she observed C. 
thomasi commonly at two locations in Cuba: Cayo Paredon and Santiago de 
Cuba. Based on examination of photographs, she suggested that these 
appeared to be C. t. bethunebakeri. However, no specimens were 
collected and, to our knowledge, there have been no additional studies 
of the Cuban C. thomasi. Craves (2004, p. 43) suggested the possibility 
that C. t. bethunebakeri recolonized Florida from Cuba.
    We acknowledge the concerns raised by some commenters regarding 
taxonomy, but we do not have any scientific evidence to suggest that 
Cyclargus thomasi bethunebakeri also now occurs in Cuba or that it 
recently immigrated from Cuba to Florida. Other subspecies of C. 
thomasi occur in the Caribbean (Smith et al. 1994, p. 129), and it is 
possible that the unidentified C. thomasi in Cuba is one of these 
subspecies, another subspecies that has not yet been described, or 
possibly C. t. bethunebakeri. Additional work to better understand the 
full range of the Miami blue outside of the known locations would be 
helpful. Surveys of remote areas in Florida are ongoing; additional 
surveys in the Bahamas (and Cuba) would be helpful. Additional research 
could help determine if other Caribbean taxa are also imperiled.
    It is unlikely that Cyclargus thomasi has only recently established 
in the lower Keys, as one commenter suggested. There were few 
historical surveys for butterflies at BHSP or KWNWR; therefore, it is 
unknown how long the Miami blue occurred at these locations prior to 
their discoveries. By contrast, many of the other islands in the lower 
Keys have been continually monitored for butterflies for several 
decades. If the Miami blue had recently colonized the lower Keys, it 
seems likely that it would have attempted to establish at numerous 
locations along the chain of islands, thereby being observed and 
reported prior to ultimately colonizing BHSP and KWNWR.
    The concern that captive Miami blue larvae may not have readily 
accepted balloonvine as the basis of historical and contemporary 
populations being different entities seems unfounded. Captive 
individuals and artificial conditions may produce responses that are 
different than those occurring in the wild. Available scientific 
literature documents a variety of host plants for the Miami blue (see 
Life History and Habitat under Background--and response to Comment 
6, above). Balloonvine was likely only one of several legumes 
used by historical Miami blue populations.
    Based on the best scientific information, including recent genetic 
work, we find that Cyclargus thomasi bethunebakeri is a distinct and 
unique entity, that it is limited in distribution (i.e., Florida, 
possibly Bahamas), that it is imperiled, and that listing is warranted. 
We lack any substantial information or evidence that the Cuban entity 
is the same taxon and have no information on that entity's abundance or 
status.
    (29) Comment: In support of our determination, one commenter, who 
had conducted her dissertation on the taxon, unequivocally stated that 
the Florida subspecies, Cyclargus thomasi bethunebakeri, is unique and 
imperiled. In addition to the work by multiple, independent scientists 
who have verified the unique standing of the Miami blue through 
dissection, this commenter cited her own additional genetic analyses, 
which compared genetic sequence data of a mitochondrial gene useful in 
elucidating species distinctions, and her finding of sequence 
differences between multiple specimens of C. thomasi from Florida, 
Cuba, and the Bahamas. The sequence data and genitalic dissections

[[Page 20964]]

make it possible to separate the bethunebakeri from others in the C. 
thomasi complex. This commenter definitively stated that C. thomasi 
bethunebakeri is unique and imperiled. She noted that other Caribbean 
taxa are also unique and recommended research to determine if these are 
also imperiled. Sequencing of specimens at additional mitochondrial and 
nuclear markers would be helpful in more fully understanding the 
relationship between Floridian and other Caribbean taxa of Cyclargus 
thomasi.
    Our Response: We agree. Based on the best scientific information, 
including recent genetics work, we find that Cyclargus thomasi 
bethunebakeri is a distinct and unique entity, that it is limited in 
distribution (i.e., Florida, possibly Bahamas), that it is imperiled, 
and that listing is warranted. We agree with the commenter's suggestion 
for additional research to help determine if other Caribbean taxa are 
also imperiled.
Comments Related to Threats
    (30) Comment: One commenter provided considerable new information 
on exotic green iguanas within KWNWR, potential impacts on the Miami 
blue, and prospects for eradication. This commenter identified studies 
to determine if green iguanas are eating blackbead in KWNWR as an 
immediate research need. He also noted that, worldwide, there are no 
known cases in which an exotic reptile, once established in an area, 
has been eradicated (citing G.H. Rodda, pers. comm. 2011).
    Our Response: We have incorporated new information pertaining to 
green iguanas within KWNWR into the text of this final rule (see 
Summary of Factors Affecting the Species, Factor E). We agree that 
determining iguana food sources, both at KWNWR and within habitat 
formerly occupied by Miami blues, is a crucial first step in preventing 
further harm to the Miami blue from this exotic species. Because Miami 
blues have historically fed on a variety of legumes, studies are needed 
to determine iguana seasonal dietary preferences in south Florida and 
the Keys. We are working with the U.S. Geological Survey (USGS), the 
State, researchers, and others to analyze gut contents of iguanas 
removed from current and historical locations. Preliminary gut content 
analyses conducted by FDEP and researchers have confirmed ingestion of 
at least one host plant (nickerbean) in the lower Keys (Jim Duquesnel, 
pers. comm. 2012).
    We agree that there is an urgent need to better understand the 
extent of threat to the Miami blue and its host plants posed by iguanas 
at KWNWR and elsewhere. Efforts to better understand this threat and 
control or contain iguanas in select areas of Miami blue habitat are 
continuing. The State and other partners have been actively working to 
reduce the presence and impact of iguanas at BHSP. Efforts by FWC and 
the FDEP appear to have helped control impacts to host plants at BHSP.
    Iguanas are well-established throughout the islands of KWNWR. While 
efforts have been made to assess this potential threat at the Refuge, 
we acknowledge the difficulties with controlling iguanas and likelihood 
that broad eradication efforts will be unsuccessful. In the short term, 
extensive iguana eradication or containment efforts may need to be 
focused in select occupied areas, future reintroduction sites, or other 
areas with greatest habitat potential, where damage to host plant is 
evident. Given the current distribution of iguanas in the Keys, any 
island has the potential to be quickly colonized or recolonized by 
iguanas, despite substantial control and containment efforts.
    (31) Comment: Two commenters indicated that the role of fire in 
pine rockland habitats does not need to be discussed, because the Miami 
blue is a coastal butterfly that does not currently occur in fire-
maintained habitats.
    Our Response: Historically, the Miami blue was documented from a 
variety of habitat types, including pine rocklands (Calhoun et al. 
2000, pp. 17-18) (see Habitat). We believe discussion of pine rocklands 
and the need to maintain this habitat with natural or prescribed fires 
is applicable, and have kept it in the final rule.
    (32) Comment: One commenter indicated that mismanagement has been 
an ongoing problem and that the Miami blue is thriving at remote 
locations because humans have not burned, sprayed, cleared, or 
developed habitat. She believed that Federal listing will do nothing to 
save the Miami blue.
    Our Response: We acknowledge that the Miami blue faces numerous 
threats (see Summary of Factors Affecting the Species) and that its 
persistence on a Refuge may be, in part, due to the absence of some 
threats. Protections under the Act (through sections 7, 9, and 10) and 
the recognition that immediately became available to the subspecies 
with Federal emergency listing (and will continue with permanent 
listing) will increase the likelihood that extinction can be prevented, 
and the subspecies can ultimately be recovered (see Available 
Conservation Measures, below).
    (33) Comment: One commenter stated that the most likely threats to 
the Miami blue are exotic predatory ants and the fragmentation and loss 
of critical breeding areas.
    Our Response: We acknowledge that the Miami blue faces numerous 
threats (see Summary of Factors Affecting the Species). Habitat loss 
and fragmentation and predation are two of many threats affecting the 
butterfly.
    Forys et al. (2001, p. 256) found high mortality among immature 
giant swallowtails (Papilio cresphontes) from red imported fire ant 
(Solenopsis invicta) predation in experimental trials and suggested 
other butterflies in southern Florida might also be influenced. 
Similarly, Cannon (2006, p. 7) reported high mortality of giant and 
Bahamian (Papilio andraemon) swallowtail eggs from an exotic species of 
twig ant on Big Pine Key. Salvato and Salvato (2010, p. 95) extensively 
monitored the immature stages of the Federal candidate Florida leafwing 
(Anaea troglodyta floridalis) and reported mortality from a number of 
exotic and native predators, including ants.
    We are not aware of any studies that have been conducted to 
specifically examine the role of exotic ants on the natural history of 
the Miami blue. Therefore, while we agree that exotic ants, as well as 
other invasive species, have likely played a role in the decline of the 
Miami blue, to date, no field studies have identified exotic ants as 
specific predators of this subspecies.
    (34) Comment: Other commenters acknowledged that the Miami blue 
requires an active plan for reintroduction and that novel 
reintroduction schemes will be an important part of its recovery.
    Our Response: We agree that captive propagation and reintroduction 
may be important components of the subspecies' survival and recovery, 
and that innovative methods may be needed. Actions need to be carefully 
planned, implemented, and monitored. Any future efforts should only be 
initiated after it has been determined that such actions will not harm 
the wild population, rigorous standards are met, and commitments are in 
place to increase the likelihood of success and maximize knowledge 
gained. Research with surrogate species may be helpful to better 
establish protocols and refine techniques for the Miami blue prior to 
propagation and reintroduction efforts.
    (35) Comment: One commenter stated that listing will hamper 
conservation efforts and research because of legal

[[Page 20965]]

restrictions. He claimed that some private property owners in the Keys 
have already threatened to clear vegetation from undeveloped properties 
to avoid any restrictions. He cited inconsistent funding for research 
and restoration, lack of cooperation between Federal and State agencies 
in recent times, and hindrances from permitting requirements and 
reporting efforts. This commenter suggested that the successful 
reintroductions of the Atala hairstreak (Eumaeus atala) be studied as 
an example of cooperative efforts, which were only possible because 
that butterfly was not listed.
    Our Response: We disagree with the commenter's view that listing 
will impede conservation efforts and research due to legal 
restrictions. Federal listing will increase the likelihood that 
extinction can be prevented and that the Miami blue may ultimately be 
recovered (see Available Conservation Measures, below). Funding under 
section 4 and section 6 of the Act may help implement actions that may 
be difficult to undertake otherwise. The need for a section 10 permit 
under the Act to conduct research on a species is dependent upon the 
nature of the activity and the likelihood for incidental take. Some 
research activities may require a permit; others may not. However, the 
reporting requirements of a section 10 permit provide additional 
benefit by ensuring the Service receives the most recent and best 
available scientific information. With the Miami blue population at 
critically low numbers, section 10 permits also allow us to control the 
amount of take allowed for research, which might otherwise threaten the 
subspecies through overutilization.
    We agree with the commenter's view that funding can be 
inconsistent. In general, Federal funding is limited. However, Federal 
listing increases potential funding opportunities and funding sources.
    We disagree with the commenter's assertion that State and Federal 
agencies have not worked cooperatively in recent times. Agencies 
regularly coordinate on Miami blue butterfly issues, needs, and 
actions. For example, State agencies have provided vessel 
transportation for researchers and staff conducting federally funded 
surveys in remote areas. Federal agencies have supported previous 
captive propagation efforts and more recently assisted in the formation 
of a State management plan.
    While we agree that Atala hairstreak releases throughout Florida 
demonstrate how volunteer organizations can galvanize to work locally 
towards conservation, we question its applicability to the Miami blue 
situation. It is our understanding that Atala hairstreaks were 
reintroduced to numerous areas, including locations where they had not 
historically occurred. Any reintroduction efforts for the Miami blue 
would focus on the most suitable habitat within its historical range, 
with the cooperation of landowners.
    There have been several successful reintroductions for endangered 
blue butterflies elsewhere in the United States, such as the Karner 
(Plebejus samuelis) or Mission blue (Plebejus icarioides missionensis). 
We are hopeful that researchers and other conservation partners will 
draw on guidance from these and other successful reintroductions prior 
to undertaking future captive propagation and reintroduction efforts 
for the Miami blue. State and Federal funding has been provided in 
support of previous captive propagation efforts for the Miami blue. Due 
to the subspecies' precarious status, it is imperative to identify the 
potential causes of failure from previous efforts before future efforts 
are undertaken.
    (36) Comment: One commenter contended that mosquito control 
activities have had minimal impact on the Miami blue butterfly. A 
second commenter stated that the record clearly demonstrates that 
mosquito control adulticides (insecticides targeting adult mosquitos) 
have not been a primary cause (or even a substantial contributory 
secondary cause) to mortality in the Miami blue and ``its sibling 
species.'' A third commenter stated that mosquito spraying is not an 
issue because the remaining Miami blue colonies in the KWNWR are not 
sprayed.
    Our Response: No comprehensive studies have been completed that 
examine the impact of current or historical mosquito control activities 
on Miami blue butterflies in the wild. Although there is no evidence of 
mosquito control impacts on wild Miami blue populations, potential 
impacts over the subspecies' historical range have never been examined. 
Recent research has shown that exposure to mosquito control chemicals 
in sufficient quantities can impact various butterfly species, 
including captive-bred Miami blue (Zhong et al. 2010 pp. 1967-1968; 
Hoang et al. 2011 pp. 1000-1002). Based on these findings, the Service 
determined that mosquito control pesticides can be a threat to the 
Miami blue.
    (37) Comment: One commenter stated that Hennessey and Habeck (1991) 
found no adverse effect on insect populations due to pesticide drift. A 
second commenter stated that no harm was demonstrated in Hennessey and 
Habeck (1989), Hennessey and Habeck (1991), and Hennessey et al. (1992) 
when mosquito control chemicals drifted 750 meters into protected no-
spray zones.
    Another commenter cited two studies (Davis and Peterson 2008, 
Breidenbach and Szalay 2010) that demonstrated few deleterious effects 
on insect communities following mosquito control chemical application.
    Our Response: With regard to the first comment relating to 
pesticide drift, the results of the aforementioned field study (all 
three references detail activities associated with just one field 
study) did not provide conclusive findings regarding the effects of 
mosquito control spraying on the two butterfly species examined 
(Florida leafwing and Bartram's hairstreak [Strymon acis bartrami]). A 
greater number of adult Florida leafwing butterflies was observed in 
untreated areas during one year of the study, but this difference was 
not observed in the second year of the study (Hennessey and Habeck 
1991, p. 14). Additionally, the study revealed that one of the 
reference locations received adulticide deposition through aerial 
drift, thus compromising the utility of the location to be used as a 
reference site and making it difficult to discern any pesticide effects 
(Hennessey and Habeck 1991, pp. 29-30).
    With regard to deleterious effects of pesticides, we agree with the 
other commenter's assertion that the two studies cited did not show 
dramatic effects on insect communities following mosquito control 
activities. There were exceptions in both studies where insect numbers 
declined following treatment events (Davis and Peterson 2008, pp. 274-
276; Breidenbach and Szalay 2010, pp. 594-595). It also did not appear 
that any butterfly families were included in the study, thus making it 
difficult to draw any conclusions about mosquito control effects on 
butterflies.
    (38) Comment: Two commenters stated that current mosquito control 
application methods are improved when compared to methods used in the 
Hennessey and Habeck (1991) study that documented drift of mosquito 
control chemicals. One of the commenters specifically stated that 
mosquito spray optimization utilizing smaller and more uniform 
insecticide aerosol droplets has been shown to mitigate exposure to 
nontarget organisms. Two studies are cited (Zhong et al. 2003, 2004) in 
support of this assertion. This same commenter also stated that the 
small droplets degrade rapidly and leave little or no residue at ground 
level.

[[Page 20966]]

    Our Response: We acknowledge that mosquito control spraying 
technology has advanced in recent years. Despite these advances, recent 
research (Pierce 2009, pp. 2-15; Zhong et al. 2010, pp. 1966-1967; 
Pierce 2011, pp. 6-11; T. Bargar, USGS, pers. comm. 2011) has still 
documented quantifiable residues of mosquito control chemicals on 
filter pads and foliage in nontarget areas.
    (39) Comment: Two commenters addressed the results of Zhong et al. 
(2010), a paper that assessed exposure and acute toxicity of late 
instar Miami blue larvae to aerially applied mosquito control 
adulticides in the field. One commenter noted that he has heard and 
read multiple comments regarding the mortality level of Miami blue 
caterpillars within a mosquito control spray zone from the Zhong et al. 
(2010) study, cited in the emergency rule. This same commenter noted 
that Miami blue caterpillar mortality in the ``drift zone'' did not 
differ statistically from control organisms that were 11 mi (18 km) 
from mosquito control chemical application. The second commenter noted 
that larval mortality was insignificant in the ``drift zone'', despite 
the fact that naled (organophosphate insecticide) residues were 
detected at least once in each of those locations. This commenter 
stated that these results may indicate that other variables need to be 
studied. Vitality of the larvae, uneven distribution of naled residue, 
and the effects of distance from the spray line on butterfly mortality 
under various wind conditions and spray drift offsets are all suggested 
as additional studies.
    Our Response: The naled residues that were observed in the drift 
zone were lower in concentration than the residues in the spray zone 
(Zhong et al. 2010, p. 1966); therefore, it is not surprising that 
caterpillar mortality in the drift zone was significantly lower than in 
the spray zone. The mortality trend observed in mosquitoes placed in 
the spray, drift, and control zones also followed a clear dose-response 
similar to that of the butterfly caterpillars (Zhong et al. 2010, p. 
1969). The vitality of the larvae used in the study is confirmed by the 
fact that no larval mortality was observed in the control zone (Zhong 
et al. 2010, p. 1969). The Service agrees with the second commenter's 
suggestion that naled residue distribution and the effects of distance 
from the spray line on butterfly mortality under various wind 
conditions and spray drift offsets should be studied further.
    (40) Comment: One commenter provided quotes from a lepidopterist 
with experience studying butterflies in Florida. The lepidopterist 
presented a theory, based upon unpublished field observations, that 
mosquito control spraying may benefit butterfly species by decreasing 
parasitoids.
    Our Response: The theory presented in this comment appears to be 
based solely on an individual's qualitative observations. No 
quantitative methods or data are given or cited. Concrete evidence in 
support of such a theory would need to be provided for further 
consideration.
    (41) Comment: One commenter stated that risk-based assessments to 
address the probability of injury, based on actual field exposure, 
rather than hazard-based assessments that simply indicate the potential 
to cause injury and do not take into account environmentally relevant 
exposure scenarios, should be used when examining pesticide impacts to 
threatened and endangered species. They maintain these assessments 
should be made in terms of long-term population-level effects, rather 
than localized effects upon individual organisms. This would allow for 
``inadvertent take'' provisions of the Act to be used.
    Our Response: The Service agrees that risk-based assessments that 
take into account actual field exposure scenarios are an effective way 
to evaluate risk to threatened and endangered species. For example, in 
a recent study, field deposition values for naled on the National Key 
Deer Refuge (NKDR), Big Pine Key, were incorporated into a 
probabilistic risk assessment that predicted significant risk to common 
butterflies (Bargar 2012, pp. 1-7). Such risk assessments would examine 
direct effects on individual organisms, but would also be interpreted 
at the population level. This could be used to estimate take and 
incidental take under the Act.
    (42) Comment: One commenter stated his support for recommendations 
made by the Imperiled Species Subcommittee of the Florida Coordinating 
Council on Mosquito Control, which include requiring buffers for known 
Miami blue populations, allowing for incidental take in areas receiving 
mosquito control, and supporting additional research into nontarget 
impacts from mosquito control. The commenter also indicated that it is 
important to definitively map populations of Miami blues to ensure that 
mosquito control activities are not unnecessarily curtailed.
    Our Response: The Service supports the aforementioned 
recommendations of the Imperiled Species Subcommittee and was 
instrumental in the development of the recommendations. It is helpful 
to identify important Miami blue habitat to help reduce threats to the 
subspecies and to not unnecessarily restrict mosquito control 
operations. Mapping potential suitable habitat would be more inclusive 
and likely provide broader conservation benefits than mapping 
populations since populations can fluctuate seasonally (or even more 
frequently) based upon habitat quality, availability, and other 
factors.
    (43) Comment: One commenter believed that the Service should not 
regulate the sale, purchase, or gifts of specimens of the Miami blue 
legally obtained before the rule was enacted. With regard to the 
exception for properly documented antique specimens, he noted that the 
butterfly was not even described until 1941 and that there are not 
likely to be many specimens at least 100 years old; if such specimens 
exist, these are probably the property of major museums, not private 
collectors.
    Our Response: We disagree. We have determined that prohibiting the 
sale and purchase of Miami blue specimens obtained before this rule is 
enacted (but not specimens documented to be over 100 years old) will 
help deter collection and help safeguard the subspecies. This 
prohibition of sale or offering for sale automatically applies to all 
pre-Act specimens of species listed as endangered under the Act. Some 
authorized activities, with proper permits and documentation, would 
still be allowed (e.g., exchange of museum specimens among permitted 
institutions). We agree that it is not likely that many exempted 
specimens of at least 100 years are in existence.

Summary of Changes From Proposed Rule

    After consideration of the comments received during the public 
comment period (see above), we made changes to the final listing rule. 
Many small, nonsubstantive changes and corrections, not affecting the 
determination (e.g., updating the Background section in response to 
comments, minor clarifications) were made throughout the document. All 
substantial changes relate to similarity of appearance under section 
4(e) of the Act and applicable prohibitions and exceptions under 
section 4(d) of the Act.
    These include the following:
    (1) We reduced prohibitions for the similarity of appearance 
butterflies to include collection only. We have removed prohibitions 
regarding possession and trade for the similarity of appearance 
butterflies.
    (2) We limited the collection prohibition for the similarity of 
appearance butterflies to only portions

[[Page 20967]]

of their ranges. Collection of the similarity of appearance butterflies 
is prohibited only within the historical range of the Miami blue.
    (3) We modified the special rule under section 4(d) for the 
similarity of appearance butterflies to specify that prohibitions apply 
only to the act of collecting them in coastal south and central Florida 
within the historical range of the Miami blue butterfly.
    (4) We modified our similarity of appearance determination to 
reflect the changes outlined above (see Determination of Status).
    (5) We modified our discussion regarding the effects of the rule to 
reflect the changes outlined above (see Effects of the Rule).
    See Similarity of Appearance, Special Rule Under Section 4(d) of 
the Act, Determination of Status, and Effects of the Rule below.

Summary of Factors Affecting the Species

    Section 4 of the Act (16 U.S.C. 1533), and its implementing 
regulations at 50 CFR part 424, set forth the procedures for adding 
species to the Federal Lists of Endangered and Threatened Wildlife and 
Plants. Under section 4(a)(1) of the Act, we may determine a species to 
be endangered or threatened due to one or more of the following five 
factors: (A) The present or threatened destruction, modification, or 
curtailment of its habitat or range; (B) overutilization for 
commercial, recreational, scientific, or educational purposes; (C) 
disease or predation; (D) the inadequacy of existing regulatory 
mechanisms; or (E) other natural or manmade factors affecting its 
continued existence. Listing actions may be warranted based on any of 
the above threat factors, singly or in combination. Each of these 
factors is discussed below.
A. The Present or Threatened Destruction, Modification, or Curtailment 
of Its Habitat or Range
    The Miami blue has experienced substantial destruction, 
modification, and curtailment of its habitat and range (see Background, 
above), with an estimated >99 percent decline in area occupied (FWC 
2010, p. 11). Although many factors likely contributed to its decline, 
some of which may have operated synergistically, habitat loss, 
degradation, and fragmentation are undoubtedly major forces that 
contribute to its imperilment (Calhoun et al. 2002, pp. 13-19; Saarinen 
2009, p. 36).

Human Population Growth and Development

    The geographic range of this butterfly once extended from the Dry 
Tortugas north along the Florida coasts to about St. Petersburg and 
Daytona. It was most common on the southern mainland and the Keys, and 
more localized on the Gulf coast. Examination of museum collections 
indicated that specimens were common from the early 1900s to the 1980s; 
the butterfly was widely distributed, existing in a variety of 
locations in southern Florida for decades (Saarinen 2009, p. 46). 
However, through time, much of this subspecies' native habitat has been 
lost, degraded, or fragmented, especially on the mainland, largely from 
development and urban growth (Lenczewski 1980, p. 47; Minno and Emmel 
1994, pp. 647-648; Calhoun et al. 2002, p. 18; Carroll and Loye 2006, 
p. 25).
    On the east coast of Florida, the entire coastline in Palm Beach, 
Broward, and Miami-Dade Counties (as far south as Miami Beach) is 
densely urban, with only small remnants of native coastal vegetation 
conserved in fragmented natural areas. Most of the Gulf Coast barrier 
islands that previously supported the Miami blue, including Marco and 
Chokoloskee Islands, have experienced intense development pressure and 
undergone subsequent habitat loss (Calhoun et al. 2002, p. 18). In an 
independent survey of historical sites where the Miami blue had 
previously been observed or collected, half were found to be developed 
or no longer supporting host plants in 2002 (D. Fine, unpub. data, 
pers. comm. 2002).
    Significant land use changes have occurred through time in south 
Florida. Considering political and economic structure and changes, 
Solecki (2001, pp. 339-356) divided Florida's land-use history into 
three broad eras: frontier era (1870-1930), development era (1931-
1970), and globalization era (1971-present). Within the development 
era, Solecki (2001, p. 350) noted that: ``Tremendous change took place 
from the early 1950s to the early and mid-1970s. Between 1953 and 1973, 
nearly 5,800 km\2\ (2,300 mi\2\) (28,997 ha/year or 11,735 ac/year) of 
natural areas were lost to agricultural and urban land uses (Solecki 
and Walker, 2001).'' During this time, ``an almost continuous strip of 
urban development became present along the Atlantic coast'' and ``urban 
land uses became well established in the extreme southeastern part of 
the region, particularly around the cities of Miami and Fort 
Lauderdale, and along the entire coastline heading northward to West 
Palm Beach.''
    Saarinen (2009, pp. 42, 46) examined museum collections in the 
context of Solecki's development eras and found that Miami blue records 
for Miami-Dade County were highest in the 1930s and 1940s, prior to 
massive land use changes and urbanization. Records from Monroe County 
(including the Keys) were most numerous in the 1970s (Saarinen 2009, p. 
46). Calhoun (pers. comm. 2003b) suggested the butterfly reached peak 
abundance when balloonvine invaded clearings associated with the 
construction boom of the 1970s and 1980s in the northern Keys and 
southern mainland and became available as a suitable host plant. If so, 
this may have represented a change in primary host plant at a time when 
the subspecies was beginning to decline due to continued development 
and destruction of coastal habitat. Saarinen (2009, p. 46) could not 
correlate decreases in natural land areas with changes in the numbers 
collected (or abundance), due to several confounding factors (e.g., 
increased pesticide use, exotic species). Calhoun et al. (2002, p. 13) 
also attributed the butterfly's decline to loss of habitat due to 
coastal development, but acknowledged that other factors such as 
succession, tropical storms, and mosquito control also likely 
exacerbated the decline (see Factor E).
    Habitat loss and human population growth in coastal areas on the 
mainland and the Keys is continuing. The human population in south 
Florida has increased from less than 20,000 people in 1920 to more than 
4.6 million by 1990 (Solecki 2001, p. 345). Monroe County and Miami-
Dade County, two areas where the Miami blue was historically abundant, 
increased from less than 30,000 and 500,000 people in 1950, 
respectively, to more than 73,000 and 2.5 million in 2009 (http://quickfacts.census.gov). All available vacant land in the Keys is 
projected to be consumed by human population increases (i.e., 
developed) by 2060, including lands not accessible by automobile (Zwick 
and Carr 2006, p. 14). Scenarios developed by Massachusetts Institute 
of Technology (MIT) urban studies and planning department staff 
(Vargas-Moreno and Flaxman 2010, pp. 1-8) included both trend and 
doubling population estimates combined with climate change factors (see 
below) and show significant impacts on remaining conservation lands, 
including the refuges, within the Keys. While the rate of development 
in portions of south Florida has slowed in recent years, habitat loss 
and

[[Page 20968]]

degradation, especially in desirable coastal areas, continues and is 
expected to increase.
    Although extensive loss and fragmentation of habitat has occurred, 
significant areas of suitable larval host plants still remain on 
private and public lands. Results from surveys (2002-2003) within south 
Florida and the Keys showed that numerous areas still contained host 
plants (Emmel and Daniels 2004, pp. 3-6). Results from similar surveys 
in 2007-2009 suggested that 14 of 16 sites on the mainland and 20 of 22 
in the Keys contained suitable habitat (Emmel and Daniels 2009, pp. 6-
8). Other researchers noted that larval host plants are common in the 
Keys (Carroll and Loye 2006, p. 24; Minno and Minno 2009, p. 9). A 
search of IRC's database suggests that 79 conservation areas in south 
Florida contain Caesalpinia spp., 39 areas contain Cardiospermum spp., 
and 77 contain Pithecellobium spp. (www.regionalconservation.org/ircs/database/search). With significant areas of host plants still remaining 
in portions of the butterfly's range, there is potential for additional 
populations of the Miami blue to exist.
    Acute habitat fragmentation appears to have severely diminished the 
Miami blue's ability to repopulate formerly inhabited sites or to 
successfully locate host plants in new areas (Calhoun et al. 2002, p. 
18). Although larval host plants remain locally common, the 
disappearance of core populations and extent of habitat fragmentation 
may now prevent the subspecies from colonizing new areas (J. Calhoun, 
pers. comm. 2003b). The Miami blue appears sedentary and is not known 
to travel far from pockets of larval host plants and adult nectar 
sources (J. Calhoun, pers. comm. 2003b; Emmel and Daniels 2004, pp. 6, 
13). The presence of adult nectar sources proximal to larval host 
plants is critical to the Miami blue and may help explain its absence 
from areas that contain high larval host plant abundance but few nectar 
sources (J. Calhoun, pers. comm. 2003b; Emmel and Daniels 2004, p. 13).

Land Management Practices

    Land management practices that remove larval host plants and nectar 
sources can be a threat to the Miami blue. Some actions on public 
conservation lands may have negatively affected occupied habitat, but 
the extent of this impact is not known. For example, the Miami blue had 
been sighted in DJSP in 1996, but following removal of balloonvine as 
part of routine land management, no adults were observed (L. Cooper, 
pers. comm. 2002; J. Calhoun, pers. comm. 2003b; M. Salvato, pers. 
comm. 2003). In 2001, following the return of balloonvine, a single 
adult was observed (J. Calhoun, pers. comm. 2003b). Calhoun noted that 
the silver-banded hairstreak (Chlorostrymon simaethis), which also 
feeds on balloonvine, had also returned to the site. The silver-banded 
hairstreak has rebounded substantially on northern Key Largo within 
disturbed areas of DJSP; if any extant Miami blues remain on the 
island, reestablishment in this area is possible.
    Removal of nickerbean as part of trail maintenance and impacts to a 
tree resulting from placement of a facility may have impacted the south 
colony at BHSP in 2002 (J. Daniels, pers. comm. 2002; P. Halupa, pers. 
obs. 2002). The tree was an apparent assembly area for display by 
butterflies during courtship (J. Daniels, pers. comm. 2002). Damage to 
host plant and nectar sources from trimming and mowing during the dry 
season and herbivory by iguanas (see Factor E) impacted habitat 
conditions at BHSP in 2010 (D. Olle, NABA, pers. comm. 2010). More 
recently, the FDEP has worked to improve habitat conditions at BHSP 
through plantings, modification of its mowing practices, removal of 
iguanas, protection of sensitive areas, and other actions (R. Zambrano, 
FWC, pers. comm. 2010; D. Cook, pers. comm. 2010a, 2010b; Janice 
Duquesnel, Florida Park Service [FPS], pers. comm. 2010a, 2010b; Jim 
Duquesnel, pers. comm. 2010, 2011b; E. Kiefer, pers. comm. 2011a).
    Maintenance, including pruning of host vegetation along trails and 
roadsides, use of herbicides, and impacts from other projects could 
lead to direct mortality in occupied habitats (Emmel and Daniels 2004, 
p. 14). Habitat previously supporting immature stages of the butterfly 
on West Summerland Key is subject to periodic mowing for road 
maintenance by the Florida Department of Transportation (J. Daniels, 
pers. comm. 2003c); the butterfly no longer occurs at this location 
(Emmel and Daniels 2004, p. 3; 2009, p. 8). Since Miami blues appear 
sedentary with limited dispersal capabilities, alteration of even small 
habitat patches may be deleterious.
    Removal of host plants from conservation lands does not appear to 
be occurring on any large scale at this time. IRC has conducted 
extensive plant inventories on conservation lands within south Florida 
and is not aware of any attempts to eradicate balloonvine and noted 
that gray nickerbean has only rarely been controlled (i.e., 
purposefully removed or pruned, followed with herbicide treatment) (K. 
Bradley, pers. comm. 2002). Nickerbean is reported to occur in all of 
the State parks in the Keys. It is not removed, but where it is a 
safety hazard for visitors, such as when overgrowing into trails, it is 
trimmed (Janice Duquesnel, pers. comm. 2003). Removal of host plants in 
or near occupied habitat remains a concern, given the subspecies' small 
population size, isolated occurrences, and limited dispersal 
capabilities (see Factor E).
    Lack of prescribed fire on public lands may have adversely affected 
the Miami blue through time, but impacts are unclear. In addition to 
being found within coastal areas and hardwood hammocks, the Miami blue 
was also reported within tropical pinelands, a fire-dependent habitat 
(Minno and Emmel 1993, p. 134; Calhoun et al. 2002, p. 18). Calhoun et 
al. (2002, p. 18) reported that, until the early 1990s, the Miami blue 
most commonly occurred within pine rocklands on Big Pine Key. In the 
absence of fire, pine rockland often progresses to hardwood hammock. 
Lack of fire may have resulted in habitat loss; however, the extent to 
which this condition occurred is unclear and difficult to assess. Since 
the Miami blue is presumably sedentary, changes in vegetation due to 
this and other land management practices may have exacerbated the 
effects of fragmentation.
    As part of its listing process, the FWC has completed a biological 
status review and management plan for the subspecies (FWC 2003, pp. 1-
26). This management plan was recently revised (FWC 2010, pp. ii-39). 
Although the management plan is a fundamental step in outlining 
conservation needs, it may be insufficient for achieving conservation 
goals and long-term persistence. Recommended conservation strategies 
and actions within the plan are voluntary and dependent upon adequate 
funding, staffing, and the cooperation and participation of multiple 
agencies and private entities, which may or may not be available or 
able to assist. Conservation strategies include suggested actions to 
maintain, protect, and monitor known metapopulations; establish new 
metapopulations; and conduct additional research to support 
conservation (FWC 2010, pp. 17-26).
    In summary, a variety of land management practices on public lands 
(e.g., removal of host plants, mowing of nectar sources, and lack of 
prescribed fires) may have adversely affected the Miami blue and its 
habitat historically and continues to do so currently.

Climate Change and Sea Level Rise

    Our analyses under the Act include consideration of ongoing and 
projected

[[Page 20969]]

changes in climate. The terms ``climate'' and ``climate change'' are 
defined by the Intergovernmental Panel on Climate Change (IPCC). 
``Climate'' refers to the mean (average) and variability of different 
types of weather conditions over time, with 30 years being a typical 
period for such measurements, although shorter or longer periods also 
may be used (IPCC 2007, p. 78). The term ``climate change'' thus refers 
to a change in the mean or variability of one or more measures of 
climate (e.g., temperature or precipitation) that persists for an 
extended period, typically decades or longer, whether the change is due 
to natural variability, human activity, or both (IPCC 2007, p. 78). 
Various types of changes in climate can have direct or indirect effects 
on species. These effects may be positive, neutral, or negative and 
they may change over time, depending on the species and other relevant 
considerations, such as the effects of interactions of climate with 
other variables (e.g., habitat fragmentation) (IPCC 2007, pp. 8-14, 18-
19). In our analyses, we use our expert judgment to weigh relevant 
information, including uncertainty, in our consideration of various 
aspects of climate change.
    Climatic changes, including sea level rise, are major threats to 
south Florida, including the Miami blue and its habitat. In general, 
the IPCC reported that the warming of the world's climate system is 
unequivocal based on documented increases in global average air and 
ocean temperatures, unprecedented melting of snow and ice, and rising 
average sea level (IPCC 2007, p. 2; 2008, p. 15). On a global scale, 
sea level rise results from the thermal expansion of warming ocean 
water, water input to oceans from the melting of ice sheets, glaciers, 
and ice caps, and the addition of water from terrestrial systems 
(United Nations (UN) 2009, p. 26). Sea level rise is the largest 
climate-driven challenge to low-lying coastal areas and refuges in the 
subtropical ecoregion of southern Florida (U.S. Climate Change Science 
Program [CCSP] 2008, pp. 5-31, 5-32). The long-term record at Key West 
shows that sea level rose on average 0.088 inches (0.224 cm) annually 
between 1913 and 2006 (National Oceanographic and Atmospheric 
Administration [NOAA] 2008, p. 1). This equates to approximately 8.76 
inches (22.3 cm) in 100 years (NOAA 2008, p. 1).
    In a technical paper following its 2007 report, the IPCC (2008, p. 
28) emphasized it is very likely that the average rate of sea level 
rise during the 21st century will exceed that from 1961 to 2003, 
although it was projected to have substantial geographical variability. 
Partial loss of the Greenland and Antarctic ice sheets could result in 
many feet (several meters) of sea level rise, major changes in 
coastlines, and inundation of low-lying areas (IPCC 2008, pp. 28-29). 
Low-lying islands and river deltas will incur the largest impacts (IPCC 
2008, pp. 28-29). According to CCSP (2008, p. 5-31), much of low-lying, 
coastal south Florida ``will be underwater or inundated with salt water 
in the coming century.'' This means that most occupied, suitable, and 
potential habitat for Miami blue will likely be either submerged or 
affected by increased flooding.
    The 2007 IPCC report found a 90 percent probability of an 
additional 7 to 23 inches (18-58 cm) and possibly as high as many feet 
(several meters) of sea level rise by 2100 in the Keys. This would 
cause major changes to coastlines and inundation of low-lying areas 
like the Keys (IPCC 2008, pp. 28-29). The IPCC (2008, pp. 3, 103) 
concluded that climate change is likely to increase the occurrence of 
saltwater intrusion as sea level rises. Since the 1930s, increased 
salinity of coastal waters contributed to the decline of cabbage palm 
forests in southwest Florida (Williams et al. 1999, pp. 2056-2059), 
expansion of mangroves into adjacent marshes in the Everglades (Ross et 
al. 2000, pp. 9, 12-13), and loss of pine rockland in the Keys (Ross et 
al. 1994, pp. 144, 151-155).
    Hydrology has a strong influence on plant distribution in these and 
other coastal areas (IPCC 2008, p. 57). Such communities typically 
grade from salt to brackish to freshwater species. In the Keys, 
elevational differences between such communities are very slight (Ross 
et al. 1994, p. 146), and horizontal distances are also small. Human 
developments will also likely be significant factors influencing 
whether natural communities can move and persist (IPCC 2008, p. 57; 
CCSP 2008, p. 7-6). For the Miami blue, this means that much of the 
butterfly's habitat in the Keys, as well as habitat in other parts of 
its historical range, will likely change as vegetation changes. Any 
deleterious changes to important host plants and nectar sources could 
further diminish the likelihood of the subspecies' survival and 
recovery.
    The Nature Conservancy (TNC) (2010, pp. 1-4) used Light Detection 
and Ranging (LIDAR) remote sensing technology to derive digital 
elevation models and project future shorelines and distribution of 
habitat types for Big Pine Key based on sea level rise projections by 
2100, ranging from the best case to worst case scenarios described by 
current scientific literature. In the Keys, models projected that sea 
level rise will first result in the conversion of habitat and 
eventually the complete inundation of habitat. In the best case 
scenario, a rise of 7 inches (18 cm) would result in the inundation of 
1,840 ac (745 ha) (34 percent) of Big Pine Key and the loss of 11 
percent of the island's upland habitat (TNC 2010, p. 1). In the worst 
case scenario, a rise of 4.6 feet (140 cm) would result in the 
inundation of about 5,950 ac (2,409 ha) (96 percent) and the loss of 
all upland habitat (TNC 2010, p. 1). If modeling is accurate, under the 
worst case scenario, even upland habitat on Big Pine Key will become 
submerged, thereby making the butterfly's potential recolonization or 
survival at this and other low-lying locations in the Keys very 
unlikely.
    Similarly, using a spatially explicit model for the Keys, Ross et 
al. (2009, p. 473) found that mangrove habitats will expand steadily at 
the expense of upland and traditional habitats as sea level rises. Most 
of the upland and transitional habitat in the central portion of 
Sugarloaf Key is projected to be lost with a 0.2-meter rise (0.7-foot 
rise) in sea level; a 0.5-meter rise (1.6-foot rise) in sea level can 
result in a 95 percent loss of upland habitat by 2100 (Ross et al. 
2009, p. 473). Furthermore, Ross et al. (2009, pp. 471-478) suggested 
that interactions between sea level rise and pulse disturbances (e.g., 
storm surges or fire [see Factor E]) can cause vegetation to change 
sooner than projected based on sea level alone.
    Scientific evidence that has emerged since the publication of the 
IPCC Report (2007) indicates an acceleration in global climate change. 
Important aspects of climate change seem to have been underestimated 
previously, and the resulting impacts are being felt sooner. For 
example, early signs of change suggest that the 1 [deg]C of global 
warming the world has experienced to date may have already triggered 
the first tipping point of the Earth's climate system--the 
disappearance of summer Arctic sea ice. This process could lead to 
rapid and abrupt climate change, rather than the gradual changes that 
were forecasted. Other processes to be affected by projected warming 
include temperatures, rainfall (amount, seasonal timing, and 
distribution), and storms (frequency and intensity) (see Factor E). The 
MIT scenarios combine various levels of sea level rise, temperature 
change, and precipitation differences with population, policy 
assumptions, and conservation funding changes. All of the scenarios, 
from small climate change shifts to major changes, will have 
significant effects on the Keys.

[[Page 20970]]

    Several recent scientific publications have also addressed problems 
that the IPCC's approach had in accounting for the observed level of 
sea level rise in the late 20th and early 21st centuries, and yielded 
new projections which reflect the possibility of rapid contributions 
from ice sheet dynamics beyond surface melting (see summaries by Church 
et al. 2010, Rahmstorf 2010, and Nicholls et al. 2011). The ranges of 
recent projections of global sea level rise (Pfeffer et al., 2008, p. 
1340, Vermeer & Rahmstorf 2009, p. 21530, Grinsted et al., 2010, pp. 
469-470, Jevrejeva et al., 2010, L07703, p. 4, (GCCUS) 2009, p. 25) all 
indicate substantially higher levels than the projection by the IPCC in 
2007, suggesting that the impact of sea level rise on south Florida 
could be even greater than indicated above. These recent studies also 
show a much larger difference (approximately 3 to 4 ft (0.9 to 1.2 m)) 
from the low to the high ends of the ranges, which indicates the 
magnitude of global mean sea level rise at the end of this century is 
still quite uncertain.
    Rising sea level is an acute threat to all sites known to currently 
support the Miami blue (Cannon et al. 2010, p. 852), and it appears 
that habitat is now being lost (T. Wilmers, pers. comm. 2012a). Most 
occupied sites are <1 meter (1.09 yd) above sea level, and none are >2 
meter (2.18 yd) above sea level (Cannon et al. 2010, p. 852). Prominent 
beach erosion and narrowing of dunes and coastal strands have been 
documented within Boca Grande and at least one island within the 
Marquesas (Cannon et al. 2010, p. 852). Considerable blackbead on one 
island has eroded into the sea (T. Wilmers, pers. comm. 2012a).

Summary of Factor A

    We have identified a number of threats to the habitat of the Miami 
blue which have operated in the past, are impacting the subspecies now, 
and will continue to impact the subspecies in the future. The decline 
of butterflies in south Florida is primarily the result of the long-
lasting effects of habitat loss, degradation, and modification from 
human population growth and associated development and agriculture. 
Environmental effects resulting from climatic change, including sea 
level rise, are expected to become severe in the future and result in 
additional habitat losses. Although efforts have been made to restore 
habitat in some areas, the long-term effects of large-scale and wide-
ranging habitat modification, destruction, and curtailment will last 
into the future. Therefore, based on our analysis of the best available 
information, present and future loss and modification of the 
subspecies' habitat is a significant threat to the subspecies 
throughout all of its range.
B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes
Collection
    Rare butterflies and moths are highly prized by collectors, and an 
international trade exists in specimens for both live and decorative 
markets, as well as the specialist trade that supplies hobbyists, 
collectors, and researchers (Collins and Morris 1985, pp. 155-179; 
Morris et al. 1991, pp. 332-334; Williams 1996, pp. 30-37). The 
specialist trade differs from both the live and decorative market in 
that it concentrates on rare and threatened species (U.S. Department of 
Justice [USDJ] 1993, pp. 1-3; United States v. Skalski et al., Case No. 
CR9320137, U.S. District Court for the Northern District of California 
[USDC] 1993, pp. 1-86). In general, the rarer the species, the more 
valuable it is; prices can exceed $25,000 for exceedingly rare 
specimens. For example, during a 4-year investigation, special agents 
of the Service's Office of Law Enforcement executed warrants and seized 
more than 30,000 endangered and protected butterflies and beetles, with 
a total wholesale commercial market value of about $90,000 in the 
United States (USDJ 1995, pp. 1-4). In another case, special agents 
found at least 13 species protected under the Act, and another 130 
species illegally taken from lands administered by the Department of 
the Interior and other State lands (USDC 1993, pp. 1-86; Service 1995, 
pp. 1-2). Law enforcement agents routinely see butterfly species 
protected under the Convention on International Trade in Endangered 
Species of Wild Fauna and Flora (CITES) during port inspections in 
Florida, often without import declarations or the required CITES 
permits (E. McKissick, Service Law Enforcement, pers. comm. 2011).
    Several listings of butterflies as endangered or threatened species 
under the Act have been based, at least partially, on intense 
collection pressure. Notably, the Saint Francis' satyr (Neonympha 
mitchellii francisci) was emergency-listed as endangered on April 18, 
1994 (59 FR 18324). The Saint Francis' satyr was demonstrated to have 
been significantly impacted by collectors in just a 3-year period (59 
FR 18324). The Callippe and Behren's silverspot butterflies (Speyeria 
callippe callippe and Speyeria zerene behrensii) were listed as 
endangered on December 5, 1997 (62 FR 64306), partially due to 
overcollection. The Blackburn's sphinx moth (Manduca blackburni) was 
listed as endangered on February 1, 2000 (65 FR 4770), partially due to 
overcollection by private and commercial collectors. The Schaus 
swallowtail (Heraclides [Papilio] aristodemus ponceanus), the only 
other federally listed butterfly in Florida, was reclassified from 
threatened to endangered in 1984 due to its continued decline (49 FR 
34501). At the time of its original listing, some believed that 
collection represented a threat. As the Schaus decreased in 
distribution and abundance, collection was estimated to be a greater 
threat than at the time of listing (49 FR 34501).
    Collection was cited as a threat to the Miami blue in both the 
original and subsequent petitions for emergency listing. The State's 
management plan for the Miami blue acknowledges that butterfly 
collecting may stress small, localized populations and lead to the loss 
of individuals and genetic variability, but also indicates that there 
is no evidence or information on current or past collection pressure on 
the Miami blue (FWC 2010, p. 13). Butterflies in small populations are 
vulnerable to harm from collection (Gall 1984, p. 133). A population 
may be reduced to below sustainable numbers (Allee effect) by removal 
of females, reducing the probability that new colonies will be founded. 
Collectors can pose threats to butterflies because they may be unable 
to recognize when they are depleting colonies below the thresholds of 
survival or recovery (Collins and Morris 1985, pp. 162-165). There is 
ample evidence of collectors impacting other imperiled and endangered 
butterflies (Gochfeld and Burger 1997, pp. 208-209), host plants (Cech 
and Tudor 2005, p. 55), and even contributing to extirpations (Duffey 
1968, p. 94). For example, the federally endangered Mitchell's satyr 
(Neonympha mitchellii mitchellii) is believed to have been extirpated 
from New Jersey due to overcollecting (57 FR 21567; Gochfeld and Burger 
1997, p. 209).
    Although we do not have evidence of collection of the Miami blue, 
we do have evidence of illegal collection of other butterflies from 
Federal lands in south Florida, including the endangered Schaus 
swallowtail. In 1993, three defendants were indicted for conspiracy to 
violate the wildlife laws of the United States, including the Act, the 
Lacey Act, and 18 U.S.C. 371 (USDC 1993, p. 1). Violations involved 
numerous listed, imperiled, and common species from many locales; 
defendants later pled guilty to the felonies (Service 1995, p. 1). As 
part of the evidence cited in the case, defendants exchanged 
butterflies

[[Page 20971]]

taken from County and Federal lands in Florida and acknowledged that it 
was best to trade ``under the table'' to avoid permits and ``extra red 
tape'' because some were on the endangered species list (USDC 1993, p. 
9). Acknowledging the difficulties in obtaining Schaus swallowtail, 
defendants indicated that they would traffic amongst each other to 
exchange a Schaus for other extremely rare butterflies (USDC 1993, p. 
10). These defendants engaged in interstate commerce, exchanging a male 
Schaus in 1984 in the course of a commercial activity (USDC 1993, p. 
11). One defendant also trafficked with a collector in Florida, dealing 
the federally listed San Bruno elfin butterfly (Callophrys mossii 
bayensis) (USDC 1993, p. 67).
    Illegal collection of butterflies on State, Federal, and other 
lands in Florida appears ongoing, prevalent, and damaging. As part of 
the aforementioned case, one defendant, who admitted getting caught 
collecting within ENP and Loxahatchee National Wildlife Refuge, stated 
that he ``got away with it each time, simply claiming ignorance of the 
laws * * *.'' (USDC 1993, p. 13). Another defendant detailed his 
poaching in Florida and acquisition of federally endangered 
butterflies, acknowledging that he had ``fared very well, going 
specifically after rare stuff'' (USDC 1993, pp. 28-29). The same 
defendant offered to traffic atala hairstreaks (Eumaeus atala), noting 
that he did not do very well and had only taken about ``600 bugs in 9 
days'' and that this number seemed poor for Florida (USDC 1993, p. 46). 
He further stated that collecting had become difficult in Florida due 
to restrictions and extreme loss of habitat, admitting that he needed 
to poach rare butterflies from protected parks (USDC 1993, p. 45). 
Methods to poach wildlife and means to evade wildlife regulations, 
laws, and law enforcement were given as part of the evidence (USDC 
1993, pp. 32-33). In a separate incident in 2008, an individual was 
observed attempting to take butterflies from Service lands in the Keys 
(D. Pharo, pers. comm. 2008). When confronted by a FWC officer, he lied 
about his activities; a live swallowtail butterfly (unidentified) was 
found in an envelope on his person, a collapsible butterfly net was 
found in a nearby area, and a cooler containing other live butterfly 
species was in his car (D. Pharo, pers. comm. 2008).
    Additionally, we are aware of and have documented evidence of 
interest in the collection of other imperiled butterflies in south 
Florida. In the aforementioned indictment, one defendant noted that 
there was a ``huge demand for Florida stuff,'' that he knew ``exactly 
where all the rare stuff is found,'' that he ``can readily get 
material,'' and that in most cases he would ``have to poach the 
material from protected parks'' (USDC 1993, p. 44). More recently, one 
commenter stated that she has been contacted by someone interested in 
acquiring rare butterflies (see Comment 5 and Response above). 
In addition, Salvato (pers. comm. 2011e) has also been contacted by 
several individuals requesting specimens of two Federal candidates, the 
Florida leafwing and Bartram's hairstreak, or seeking information 
regarding locations where they may be collected in the field. In 
addition, interest in the collection of the Florida leafwing was posted 
by two parties on at least one Web site in 2010 along with advice on 
where and how to bait trap, despite the fact that this butterfly mainly 
occurs on Federal lands within ENP. Thus, there is established and 
ongoing collection pressure for rare butterflies, including two other 
highly imperiled candidate species in south Florida.
    We are also aware of multiple Web sites that offer or had offered 
specimens of south Florida butterflies for sale that are candidates for 
listing under the Act (M. Minno, pers. comm. 2009; C. Nagano, pers. 
comm. 2011; D. Olle, pers. comm. 2011). Until recently, one Web site 
offered male and female Florida leafwing specimens for [euro]110.00 and 
[euro]60.00 (euros), respectively (approximately $144 and $78). It is 
unclear from where the specimens originated or when these were 
collected, but this butterfly is now mainly restricted to ENP. The same 
Web site offered specimens of Bartram's hairstreak for [euro]10.00 
($13). Although the specifics on its collection are not clear, this 
butterfly now mainly occurs on protected Federal, State, and County 
lands. The same Web site offers specimens of other butterflies similar 
in appearance to the Miami blue; the cassius blue is available for 
[euro]4.00-10.00 ($5-$13). Additionally, other subspecies of Cyclargus 
thomasi that occur in foreign countries are also for sale. It is clear 
that a market currently exists for both imperiled species and those 
similar in appearance to the Miami blue.
    The potential for unauthorized or illegal collection of the Miami 
blue (eggs, larvae, pupae, or adults) exists, despite its State-
threatened status and the protections provided on Federal (and State) 
land. Illegal collection could occur without detection at remote 
islands of KWNWR because these areas are difficult to patrol. The 
localized distribution and small population size render this butterfly 
highly vulnerable to impacts from collection. At this time, removal of 
any individuals may have devastating consequences to the survival of 
the subspecies. Although the Miami blue is no longer believed to be 
present at BHSP, its return is possible. At BHSP, the butterfly, like 
other wildlife and plant species within the Florida park system, is 
protected from unauthorized collection (Chapter 62 D-2.013(5)) (see 
Factor D). However, because BHSP is so heavily used, continual 
monitoring for illegal collections is a challenge. Daniels (pers. comm. 
2002) believed that additional patrols would be helpful because 
unauthorized collection of specimens is possible, even though 
collection is prohibited. In addition, any colonies that might be found 
or become established outside of BHSP or other protected sites would 
also not be patrolled and would be at risk of collection.
    Although the Miami blue's status as a State-threatened species 
provides some protection, this protection does not include provisions 
for other species of blues that are similar in appearance. Therefore, 
it is quite possible that collectors authorized to collect similar 
species may inadvertently (or purposefully) collect the Miami blue 
butterfly thinking it was, or planning to claim they thought it was, 
the cassius blue, nickerbean blue, or ceraunus blue, which can also 
occur in the same general geographical area and habitat type. Federal 
listing of other similar butterflies can partially reduce this threat 
(see Similarity of Appearance below) and provide added protective 
measures for the Miami blue above those afforded by the State.
    In summary, due to the few metapopulations, small population size, 
restricted range, and remoteness of occupied habitat, we have 
determined that collection is a significant threat to the subspecies 
and could potentially occur at any time. Even limited collection from 
the small population in KWNWR (or other populations, if discovered) 
could have deleterious effects on reproductive and genetic viability 
and thus could contribute to its extinction.

Scientific Research and Conservation Efforts

    Some techniques (e.g., capture, handling) used to understand or 
monitor the Miami blue have the potential to cause harm to individuals 
or habitat. Visual surveys, transect counts, and netting for 
identification purposes have been performed during scientific research 
and conservation efforts with the potential to disturb or

[[Page 20972]]

injure individuals or damage habitat. Mark-recapture, a common method 
used to determine population size, has been used by some researchers to 
monitor Miami blue populations. This method has received some 
criticism. While mark-recapture may be preferable to other sampling 
estimates (e.g., count-based transects) in obtaining demographic data 
when used in a proper design on appropriate species, such techniques 
may also result in deleterious impacts to captured butterflies (Mallet 
et al. 1987, pp. 377-386; Murphy 1988, pp. 236-239; Haddad et al. 2008, 
pp. 929-940). Although effects may vary depending upon taxon, 
technique, or other factors, some studies suggest that marking may 
damage or kill butterflies or alter their behaviors (Mallet et al. 
1987, pp. 377-386; Murphy 1988, pp. 236-239). Murphy (1988, p. 236) and 
Mattoni et al. (2001, p. 198) indicated that studies on various 
lycaenids have demonstrated mortality and altered behavior as a result 
of marking. Conversely, other studies have found that marking did not 
harm individual butterflies or populations (Gall 1984, pp. 139-154; 
Orive and Baughman 1989, p. 246; Haddad et al. 2008, p. 938). No 
studies have been conducted to determine the potential effects of 
marking on the Miami blue. Although data are lacking, researchers 
permitted to use such techniques have been confident in their abilities 
to employ the techniques safely with minimal effect on individuals 
handled. Researchers currently studying the population within KWNWR 
have opted not to use mark-release-recapture techniques due to the 
potential for damage to this small, fragile butterfly (Haddad and 
Wilson 2011, p. 3).
    Captive propagation and reintroduction activities may present risks 
if wild populations are impacted or if the species is introduced to new 
or inappropriate areas outside of its historical range (65 FR 56916-
56922, September 20, 2000). Although butterflies were successfully 
reared in captivity at the UF with the support of State and Federal 
agencies, efforts to reintroduce the Miami blue to portions of its 
historical range did not result in the establishment of any new 
populations (Emmel and Daniels 2009, pp. 4-5; FWC 2010, p. 8). While 
some monitoring occurred following releases, it is not clear why 
captive-reared individuals did not persist in the wild. Perhaps 
experiments using surrogate species (e.g., other lycaenids) and more 
structured and intense monitoring following releases can help elucidate 
possible causes for failure and improve chances for reestablishment in 
the future.
    Declines in the captive colony in 2005 and 2006 were attributed to 
a baculovirus; consequently, this captive colony was terminated after 
30 generations and another was started with new stock from BHSP 
(Saarinen 2009, p. 92). Baculovirus infections are capable of 
devastating both laboratory and wild butterfly populations (Saarinen 
2009, pp. 99, 119). Irrevocable consequences may occur if a pathogen is 
transferred from laboratory-reared to wild populations. Genetic 
diversity within the captive colony was lost over time (between 
generations) (Saarinen 2009, p. 100). At one point, the captive colony 
was not infused with new genetic material for approximately 1 year due 
to low numbers within the wild population. As a result, decreases in 
genetic diversity, allelic richness, and number of individuals produced 
occurred during this time (Saarinen 2009, p. 100). While captive 
propagation and reintroduction efforts offer enormous conservation 
potential, there can be associated risks and ramifications to both wild 
and captive-reared individuals and populations.
    The use of captive-reared Miami blues in pesticide-use and life-
history studies can be questioned and has been criticized by some (FWC 
2010, p. 10). All experiments were conducted with captive-reared 
individuals; no wild individuals were used. Individuals used in 
experiments were not intended for release back into the wild or were 
reared specifically for this purpose. Researchers involved with the 
captive colony and others conducting scientific studies or other 
conservation efforts were authorized by appropriate agencies to conduct 
such work.

Summary of Factor B

    Collection interest of imperiled butterflies is high, and there are 
ample examples of collection pressure contributing to extirpations. 
Although we do not have information indicating that Miami blues are 
being collected, we consider collection to be a significant threat to 
the subspecies due to the few remaining metapopulations, small 
population size, restricted range, and remoteness of occupied habitat, 
and because collection could potentially occur at any time. Even 
limited collection from the remaining metapopulation could have 
deleterious effects on reproductive and genetic viability of the 
subspecies and could contribute to its extinction.
    Captive propagation and reintroduction may be important components 
of the subspecies' survival and recovery, but such actions need to be 
carefully planned, implemented, and monitored. Any future efforts 
should only be initiated after it has been determined that such actions 
will not harm the wild population, rigorous standards are met, and 
commitments are in place to increase the likelihood of success and 
maximize knowledge gained.
    Based on our analysis of the best available information, there is 
no evidence to suggest that its vulnerability to collection and risks 
associated with scientific or conservation efforts will change in the 
future.
C. Disease or Predation
    The effects of disease or predation are not well known. Because the 
Miami blue is known from only a few locations and population size 
appears low, disease and predation could pose a threat to its survival.

Disease

    A baculovirus was confirmed within the captive colony, and 
infection caused the death of Miami blue larvae in captivity (see 
Factor B above) (Saarinen 2009, p. 120). Pathogens have affected other 
insect captive-breeding programs, however, this was the first time a 
baculovirus was found to affect a captive colony of an endangered 
Lepidopteran (Saarinen 2009, p. 120). A baculovirus or other disease or 
pathogens have the potential to destroy wild populations (Saarinen 
2009, p. 99). Nice et al. (2009, p. 3137) identified widespread 
infection from the endosymbiotic bacterial Wolbachia within western 
populations of the endangered Karner blue (Lycaeides samuelis) and 
indicated the bacteria may also pose a significant threat towards other 
endangered arthropods. Plant pathogens could also negatively impact 
host plant survival, host growth, or the production of terminal host 
growth available to developing larvae (Emmel and Daniels 2004, p. 14). 
At this time, there is no information to suggest that disease or 
pathogens are affecting Miami blue butterflies or host plants in the 
wild.

Predation

    Predation of adults or immature stages was not observed during 
monitoring at BHSP, despite the presence of potential predators (Emmel 
and Daniels 2004, p. 12; Trager 2009, p. 152). Several species of 
social wasps, specifically paper wasps (Polistes) and yellow jackets 
(Vespula), are known to depredate Lepidoptera on nickerbean and 
surrounding vegetation at BHSP and other sites with suitable habitat, 
but

[[Page 20973]]

predation on Miami blue larvae was not observed (Trager 2009, p. 152). 
Carroll and Loye (2006, p. 18) encountered a parasitic wasp, 
Lisseurytomella flava, during their studies of the balloonvine insects 
on northern Key Largo during the late 1980s. No wasp parasitism towards 
Miami blue larvae was noted (Carroll and Loye 2006, p. 24). However, 
this wasp, along with the Miami blue, was absent from continued 
balloonvine sampling in 2003, suggesting the wasp may have used the 
butterfly as host.
    Cannon et al. (2007, p. 16) observed wasps (unidentified) eating 
Miami blue larvae at KWNWR; wasps and dragonflies were also observed to 
chase adults in flight. Adult Miami blues were found entrapped in the 
webs of silver orb spiders (Argiope argentata) (Cannon et al. 2007, p. 
16). Trager (2009, pp. 149, 153-154) indicated that the Miami blue is 
likely depredated under natural conditions, but only predation by an 
adult brown anole lizard (Anolis sagrei) was observed during field 
studies. Iguanas likely consume eggs and pupae when opportunistically 
feeding on host plants (P. Hughes, pers. comm. 2009; Daniels 2009, p. 
5; FWC 2010, p. 13), especially since the butterfly uses the same 
terminal growth of host plants that iguanas typically eat (see Factor 
E). Predators and parasitoids have been suggested as potential 
contributors to the butterfly's decline (M. Minno, pers. comm. 2010), 
but this has not been observed or confirmed in the field (Trager 2009, 
p. 149; Minno and Minno 2009, p. 78; FWC 2010, pp. 13, 24).
    The extent to which native or exotic ants and other predators and 
parasitoids may pose a threat to the Miami blue is not clear, but 
deserves further attention. For example, invasive fire ants (Solenopsis 
invicta) were first confirmed in counties within the historical range 
of the Miami blue as early as 1958 (Hillsborough); presence was 
confirmed in additional counties in the late 1960s (Brevard and 
Volusia) and 1970s (Broward, Collier, Miami-Dade, Lee, Monroe) 
(Callcott and Collins 1996, p. 249); infestation has since expanded. In 
addition to the possible direct effects of predation, fire ants can 
also disrupt arthropod communities and displace native ants. In one 
study, Porter and Savignano (1990, pp. 2095-2106) found that S. invicta 
reduced species richness by 70 percent and abundance of native ants by 
90 percent.
    Both the red imported fire ant and the little fire ant (Wasmannia 
auropunctata), another invasive exotic ant, currently occur at BHSP 
(Saarinen and Daniels 2006, p. 71). Fire ants have also been found on 
all beaches within KWNWR (Wilmers et al. 1996, pp. 341-343; Wilmers 
2011, pp. 20-21; T. Wilmers, pers. comm. 2012a). In one study in Key 
Largo, fire ants were found within half of the study transects and in 
close proximity to the edge of hardwood hammock habitat (Forys et al. 
2001, p. 257). Forys et al. (2001, p. 257) found all immature 
swallowtail life stages to be vulnerable to predation by imported fire 
ants and recognized the potential impact of this predatory insect on 
the federally endangered Schaus swallowtail and other butterflies in 
south Florida. Thus, immature life stages of the Miami blue may be 
vulnerable to predation by fire ants within its current known locations 
or if the butterfly still persists, elsewhere in its historical range.
    In a greenhouse situation, Trager (2009, p. 151) observed fire ants 
removing Miami blue eggs in an indoor flight cage, but noted that the 
ants did not attack larvae on the same plant. In his studies, a captive 
colony of fire ants was found to consume captive-reared Miami blue 
pupae in food trays; however, the ants did not remove newly laid eggs 
from the host plant and even exhibited weak tending behavior toward 
larvae (Trager 2009, pp. 151-152). At this time, it is unclear to what 
extent native and exotic predatory insects may be impacting wild Miami 
blue populations.
    Some ant species may also protect Miami blue larvae against 
parasitoids and predators; however, this has not yet been observed in 
the wild (Trager and Daniels 2009, 479; Trager 2009, p. 101). In 
laboratory studies, Camponotus floridanus ants have been shown to 
display strong defensive behaviors (e.g., rapidly circling larvae, 
recruiting nearby workers, and lunging at forceps) when disturbed 
(Trager and Daniels 2009, p. 480; Trager 2009, p. 102). The large size 
of this ant species and nearly constant tending may serve as a visual 
deterrent to potential attackers; however, researchers acknowledged 
that they have no definitive evidence that C. floridanus are more 
effective defenders of Miami blue larvae than small-bodied ant species 
(Trager and Daniels 2009, p. 480; Trager 2009, p. 97).
    Researchers have suggested that some ant species may depredate 
Miami blue larvae or may opportunistically tend larvae without 
providing protection against predators or other benefits (Saarinen and 
Daniels 2006, p. 73; Saarinen 2009, pp. 134, 138). However, Trager and 
Daniels (2009, pp. 478-481) recorded a universal tending response among 
ants consistent with a mutualistic interaction through both field 
observations and laboratory trials. They did not observe any 
depredation of larvae by ants in the field and, based upon 
observations, doubted that many ant species regularly depredate larvae 
(Trager and Daniels 2009, pp. 479-481; Trager 2009, p. 149).

Summary of Factor C

    Studies suggest that various stressors (e.g., baculovirus, fire 
ants) have the potential to negatively impact the Miami blue, but there 
is no information on their impacts to wild populations. The Miami blue 
may have some mechanisms to potentially deter predators and 
parasitoids, but these are not well understood. The role of predation 
and parasitism needs to be more closely examined. Disease and predation 
have the potential to impact the Miami blue's continued survival, given 
its few remaining populations, low abundance, and restricted range. 
However, we do not have information to suggest that disease and 
predation are threats to the Miami blue at this time.
D. The Inadequacy of Existing Regulatory Mechanisms
    Despite the fact that they contain several protections for the 
Miami blue, Federal, State, and local laws have not been sufficient to 
prevent past and ongoing impacts to the Miami blue and its habitat 
within its current and historical range.
    In response to a petition from the NABA in 2002, the FWC emergency-
listed the Miami blue butterfly in 2002, temporarily protecting the 
butterfly. On November 19, 2003, the FWC declared the Miami blue 
butterfly endangered (68A-27.003), making its protection permanent. On 
November 8, 2010, the FWC adopted a revised listing classification 
system, moving from a multi-tiered to single-category system. As a 
consequence of this change, the Miami blue butterfly (along with other 
species) became State-threatened; its original protective measures 
remained in place (68A-27.003, amended). This designation prohibits any 
person from taking, harming, harassing, possessing, selling, or 
transporting any Miami blue or parts thereof or eggs, larvae or pupae, 
except as authorized by permit from the executive director, with 
permits issued based upon whether issuance would further management 
plan goals and objectives. Although these provisions prohibit take of 
individuals, there is a general lack of law enforcement presence in 
many areas. In addition, existing regulations prohibit take, but do not 
provide substantive protection of Miami blue habitat or protection of 
potentially suitable habitat. Therefore, while the Miami blue butterfly 
is afforded some protection by its presence

[[Page 20974]]

on Federal (and State) lands, losses of suitable and potential habitat 
outside of these areas are expected to continue (see Factor A).
    The Miami blue's presence on Federal (and State) lands offers some 
insulation against collection, but protection is somewhat limited (see 
Factor B). Permits are necessary for authorized collection, but law 
enforcement presence on Federal and State land is often inadequate. In 
addition, many areas are difficult to patrol and the State's protection 
of the Miami blue does not extend to butterflies that are similar in 
appearance (see Similarity of Appearance below). Because there are only 
slight morphological differences between the Miami blue and other 
butterfly species in the same areas, the Miami blue remains at risk to 
illegal collection, despite the regulatory mechanisms already in place 
(see Factor B).
    As a Federal candidate subspecies, the Miami blue was afforded some 
protection through sections 7 and 10 of the Act and associated policies 
and guidelines, but protection was limited. Federal action agencies are 
to consider the potential effects to the butterfly and its habitat 
during the consultation process. Applicants and action agencies are 
encouraged to consider candidate species when seeking incidental take 
for other listed species and when developing habitat conservation 
plans. On Federal lands, such as KWNWR, candidate species are treated 
as ``proposed threatened.''
    Although the Miami blue occurs on Federal (and possibly State) land 
that offers protection, these areas are vast and often heavily used. 
Signage prohibiting collection is sometimes lacking or may not be 
advisable as it could draw attention to the presence of the subspecies; 
patrolling and monitoring of activities can be limited and dependent 
upon the availability of staffing and resources. Within KWNWR, the 
Marquesas Keys are open to the public; portions of the beach on Boca 
Grande are closed (T. Wilmers, pers. comm. 2011b). In general, occupied 
islands are remote and difficult to patrol, and trespassing and 
unauthorized uses (e.g., fire and fire pits) still occur (see Factor 
E). Therefore, the potential for illegal collection and damage to 
sensitive habitats still exists (see Factors B and E).
    Prior to its apparent extirpation, the metapopulation at BHSP was 
afforded some protection by its presence on State lands. All property 
and resources owned by FDEP are generally protected from harm in 
Chapter 62D-2.013(2), and animals are specifically protected from 
unauthorized collection in Chapter 62D-2.013(5) of the Florida 
Statutes. Exceptions are made for collecting permits, which are issued, 
``for scientific or educational purposes.'' Still, protection of 
resources at BHSP is a challenge due to the park's popularity and high 
use (See Factor E). Although in 2010, the FDEP hired a temporary, full-
time biologist to work on Miami blue conservation issues at BHSP, 
including patrol of sensitive habitats, this position has since been 
reduced to part-time.
    Permits are required from the FWC for scientific research on and 
collection of the Miami blue. For work on Federal lands (i.e., KWNWR, 
ENP, and BNP), permits are required from the Service or the NPS. For 
work on State lands, permits are required from FDEP. Permits are also 
required for work on County-owned lands.

Summary of Factor D

    Despite existing regulatory mechanisms, the Miami blue continues to 
decline due to the effects of a wide array of threats (see Factors A, 
B, and E). Based on our analysis of the best available information, we 
find that existing regulatory measures, due to a variety of 
constraints, do not work as designed, and, therefore, the existing 
regulatory mechanisms are inadequate to address threats to the 
subspecies throughout all of its range. We have no information to 
indicate that the aforementioned regulations, which currently do not 
offer adequate protection to the Miami blue, will be revised such that 
they would be adequate to provide protection for the subspecies in the 
future.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
Impacts From Iguanas
    The exotic green iguana (Iguana iguana) appears to be a severe 
threat to the Miami blue (75 FR 69258; Daniels 2009, p. 5; FWC 2010, 
pp. 6, 13; Olle 2010, pp. 4, 14). Iguanas are prevalent within the 
Keys, and sightings within occupied and potential Miami blue habitat 
are common (P. Cannon, pers. comm. 2009, 2010d, 2010e). Effects of 
iguana herbivory to the host plant (nickerbean) at BHSP were evident by 
late 2008 and early 2009 (Emmel and Daniels 2009, p. 4; Daniels 2009, 
p. 5; P. Hughes, pers. comm. 2009; P. Cannon, pers. comm. 2009; A. 
Edwards, pers. comm. 2009). In January 2009, Cannon (pers. comm. 2009) 
reported that iguanas had stripped all new nickerbean growth, causing 
substantial losses since November 2008. In April 2009, nickerbean 
showed signs of limited growth due to chronic herbivory (P. Hughes, 
pers. comm. 2009).
    In addition to damage, iguanas likely consume eggs and pupae when 
opportunistically feeding (P. Hughes, pers. comm. 2009; Daniels 2009, 
p. 5; FWC 2010, p. 13), especially since the butterfly uses the same 
terminal growth of host plants to lay eggs. For many years, host plant 
abundance within BHSP appeared capable of sustaining both iguanas and 
Miami blues. Depressed numbers of Miami blues in 2008, however, were 
likely the result of both a severe drought and impacts to the 
nickerbean from iguanas feeding on the terminal nickerbean growth (FWC 
2010, p. 6). During the winter of 2010, prolonged and unseasonably cold 
temperatures in the lower Keys resulted in a considerable decline in 
available nickerbean at BHSP (Olle 2010, p. 14). The suppressed Miami 
blue population at this site during this time may not have been able to 
survive this temporary, but severe, reduction in nickerbean, likely 
caused by the combined influences of iguanas and environmental factors 
(e.g., drought and cold).
    Iguana tracks have been found on islands occupied by the Miami blue 
in KWNWR (Cannon et al. 2007, p. 16; T. Wilmers, pers. comm. 2011c) as 
well as on three islands in GWHNWR (T. Wilmers, pers. comm. 2011b). 
Three large, gravid female iguanas were trapped and removed from the 
Marquesas in February 2011 (T. Wilmers, pers. comm. 2011d). To date, 
the presence of iguanas (burrows or tracks) has been documented on each 
of the islands known to harbor Miami blues (T. Wilmers, in litt. 
2011e). Cannon et al. (2007, p. 16) stated that the exotic herbivore 
has the potential to impact host and nectar plants. Iguana populations 
in south Florida, after long periods of slow growth, have been shown to 
irrupt (increase suddenly or rapidly in numbers) (Meshaka et al. 2004, 
pp. 157-158; Meshaka 2011, p. 52). Given the absence of predators 
within KWNWR, the iguana population may grow unchecked until limited by 
food sources or other natural factors (e.g., hurricanes). A further 
concern is that severe damage to vegetation, as occurred during 
Hurricane Wilma (Cannon et al. 2010, p. 851), may concentrate Miami 
blues and iguanas in remnant stands of blackbead, thereby magnifying 
the iguana's impact on the butterfly and its habitat (T. Wilmers, in 
litt. 2011e).
    Resource agencies are working to better understand and combat the 
threat of green iguanas in areas occupied (and

[[Page 20975]]

recently occupied) by the Miami blue. At BHSP, cooperative efforts 
resulted in the trapping and removal of 200 iguanas between November 
2009 and October 2011 (Emmel and Daniels 2009, p. 4; FWC 2010, p. 17; 
E. Kiefer, pers. comm. 2011a, 2011b; E. Cowan, FPS, pers. comm. 2011). 
Removal efforts have significantly decreased the number of iguanas 
within BHSP; these management actions will need to be an ongoing effort 
due to the prevalence of iguanas in the surrounding areas (R. Zambrano, 
pers. comm. 2009; E. Cowan, pers. comm. 2011). Efforts are also 
underway to assess and address this threat at KWNWR, but it is unclear 
if iguanas regularly consume blackbead at the Refuge (T. Wilmers, pers. 
comm. 2011a, 2011c, 2011d, 2011f). Despite cooperative efforts, the 
threat from iguanas is expected to continue due to their widespread 
distribution and the difficulties in control.

Competition

    Host resource competition from other butterfly species could 
deleteriously impact metapopulation productivity of the Miami blue. The 
introduction of or future island colonization by potential Lepidopteran 
competitors may impact the Miami blue metapopulation. The nickerbean 
blue, cassius blue, and Martial's scrub hairstreak are known to use 
various species of nickerbean host plants throughout their range 
(Glassberg et al. 2000, pp. 74-80; Calhoun et al. 2002, p. 15). The 
nickerbean blue and Martial's scrub hairstreak have been documented 
using gray nickerbean as a host plant at BHSP (Daniels et al. 2005, p. 
174; P. Cannon, pers. comm. 2010g). Such host use may represent direct 
competition for host resources (Emmel and Daniels 2004, p. 14). 
However, Calhoun et al. (2002, p. 18) believed it was unlikely that 
competition played a significant role in the decline of the Miami blue 
based on the abundance of host plant sources available to lycaenids 
throughout the Lower Keys. There is no evidence to suggest that host 
resource competition is a threat to the Miami blue at this time or is 
likely to become so in the future.

Inadvertent and Purposeful Impacts From Humans

    Inadvertent damage from humans can affect the Miami blue and its 
habitat in its current and former range. For example, the seed pods of 
balloonvine ``pop'' when squeezed and can be targeted by humans. Damage 
to balloonvine has been documented along roads in the Keys (J. Loye, 
University of California-Davis, pers. comm. 2003a, 2003b). During a 
study in the mid-1980s examining balloonvine and its associated insect 
community, Loye (pers. comm. 2003a) found a difference in insect 
diversity between sites along roads and those without road access. 
Acknowledging other possible contributing factors (e.g., mosquito 
control, car emissions), Loye (pers. comm. 2003a) indicated that 
collectors and maintenance crews damaged balloons near roads, stating 
that ``humans damaged every balloon that could be easily found at our 
study sites'' (J. Loye, pers. comm. 2003b). It is not clear what, if 
any, impact this had on the butterfly at or since that time. However, 
damage to host plants (whole or parts) could contribute to mortality of 
eggs or larvae.
    BHSP is heavily used by the public for recreational purposes, and 
although the butterfly has not been seen at this location since early 
2010, suitable habitat is located along trails and other high-use areas 
(e.g., campgrounds). Former colonies may have experienced disturbance 
from Park visitors. Trampling of host plants and well-worn footpaths 
were evident, at least periodically from 2002 to 2010, and during times 
when other stressors (e.g., cold, drought, iguanas) occurred (P. 
Halupa, pers. obs. 2002; D. Olle, pers. comm. 2010; M. Salvato, pers. 
comm. 2010a; R. Zambrano, pers. comm. 2010). To protect larval host 
plants and adult nectar sources, the FPS erected fencing and signage 
around the majority of the south colony site at BHSP. Although this is 
expected to minimize damage to the largest habitat patch, other small 
habitat patches (as small as 15.0 by 15.0 feet [4.6 by 4.6 meters]) 
elsewhere on the island are still vulnerable to intentional or 
accidental damage. Fencing small colony sites or patches of available 
habitat is impractical and would make exact locations of colonies more 
evident, possibly increasing the risk of illegal collection or harm 
should the Miami blue return to the island.
    KWNWR lacks human developments, but local disturbances result from 
illicit camping, fire pits, smugglers, vandals, and immigrant landings. 
These disturbances are generally infrequent for most islands within 
KWNWR with the exception of Boca Grande, which contains the largest 
amounts of beach. Recreational visitation is high on Boca Grande, 
particularly during weekends (Cannon et al. 2010, p. 852). Trampling of 
dune vegetation has been a long-term problem on Boca Grande, and fire 
pits have been found many times over the past two decades on both Boca 
Grande and the Marquesas Keys (Cannon et al. 2010, p. 852). Most 
recently, a fire pit was found adjacent to host plants within occupied 
habitat on Boca Grande in December 2011 (P. Cannon, pers. comm. 2012). 
The large amount of dead vegetation intermingled with host plants on 
Boca Grande and the Marquesas Keys makes the threat of fire (natural or 
human-induced), a significant threat to the Miami blue (Cannon et al. 
2007, p. 13; 2010, p. 852; P. Cannon, pers. comm. 2012; T. Wilmers, 
pers. comm. 2012b). Immature stages (eggs, larvae), which are 
sedentary, would be particularly vulnerable. Glassberg and Olle (2010, 
p. 1) asserted that ``the proximity of the islands within KWNWR, to 
both Key West and the Dry Tortugas, invite human mischief, and largely 
go unpoliced.'' These areas within KWNWR are remote and accessible 
mainly by boat, making them difficult to patrol and monitor.
    Other patches of potential and suitable habitat are susceptible to 
purposeful impacts from humans. Some private property owners in the 
Keys have reportedly threatened to clear vegetation from undeveloped 
properties to avoid any restrictions regarding the butterfly (M. Minno, 
in litt. 2011b; N. Pakhomoff-Spencer, consultant, pers. comm. 2011).
    In summary, inadvertent and purposeful impacts from humans may have 
affected the Miami blue and its habitat. Due to the location of 
occupied and suitable habitat, the popularity of these areas with 
humans, and the projected human growth, especially in coastal areas, 
such impacts from recreation and other uses are expected to continue.

Other Natural and Unnatural Changes to Habitat

    Natural changes to vegetation from environmental factors, 
succession, or other causes may now be a threat to the Miami blue 
because of its severely reduced range, few populations, and limited 
dispersal capabilities. Suitable and occupied habitat in KWNWR and 
other coastal areas is dynamic and fluctuating, influenced by a variety 
of environmental factors (e.g., storm surge, wind, precipitation). In 
2010, substantial changes in habitat conditions on Boca Grande occurred 
with the proliferation of Galactia striata, a native climbing vine (T. 
Wilmers, pers. comm. 2010a; P. Cannon, pers. comm. 2010b, 2010h, 2010i, 
2010j). The vine has enveloped a substantial amount of blackbead, 
occurring on about 40 percent of the blackbead growing on the seaward 
side at the dune interface (T. Wilmers, pers. comm. 2010a). Wilmers 
(pers. comm. 2010a) indicated that the extensive growth was likely 
fueled by the markedly higher

[[Page 20976]]

precipitation during September and October 2010 (3.47 and 2.22 inches 
[8.81 and 5.64 cm], respectively, above normal in Key West). Under 
favorable conditions, the vine first grows in the dune, then sprawls 
landward laterally, eventually ascending and blanketing blackbead (T. 
Wilmers, pers. comm. 2010a). While climbing vines can proliferate 
before eventually dying back, Wilmers (pers. comm. 2010a) stated that 
the intense proliferation in 2010 was unprecedented in his 25 years of 
work in the area. Left unchecked, this proliferation has the potential 
to impact host plants and affect the butterfly's ability to persist on 
some islands.

Invasive and Exotic Vegetation

    Displacement of native plants including host plants by invasive 
exotic species, a common problem throughout south Florida, also 
possibly contributed to habitat loss of the Miami blue. In coastal 
areas where undeveloped land remains, the Miami blue's larval food 
plants are likely to be displaced by invasive exotic plants, such as 
Brazilian pepper, Australian pine (Casuarina equesitifolia), Asian 
nakedwood (Colubrina asiatica), cat-claw vine (Macfadyena ungius-cati), 
wedelia (Spahneticola trilobata), largeleaf lantana (Lantana camara), 
Portia tree (Thespesia populnea), wild indigo (Indigofera spicata), 
beach naupaka (Scaevola taccada), and several species of invasive 
grasses. Although we do not have direct evidence of exotic species 
displacing host plants or nectar sources, we recognize this as a 
potential threat, due to the magnitude of this problem in south 
Florida.

Pesticides

    Efforts to control salt marsh mosquitoes, Aedes taeniorhynchus, 
among others, have increased as human activity and population have 
increased in south Florida. To control mosquito populations, second-
generation organophosphate (naled) and pyrethroid (permethrin) 
adulticides are applied by mosquito control districts throughout south 
Florida. In a rare case in upper Key Largo, another organophosphate 
(malathion) was applied in 2011 when the number of permethrin 
applications reached its annual limit. All three of these compounds 
have been characterized as being highly toxic to nontarget insects by 
the U.S. Environmental Protection Agency (2002, p. 32; 2006a, p. 58; 
2006b, p. 44). The use of such pesticides (applied using both aerial 
and ground-based methods) to control mosquitoes presents a potential 
risk to nontarget species, including the Miami blue butterfly.
    The potential for mosquito control chemicals to drift into 
nontarget areas and persist for varying periods of time has been well 
documented. Hennessey and Habeck (1989, pp. 1-22; 1991, pp. 1-68) and 
Hennessey et al. (1992, pp. 715-721) illustrated the presence of 
mosquito spray residues long after application in habitat of the Schaus 
swallowtail and other imperiled species in both the upper (Crocodile 
Lake NWR, North Key Largo) and lower Keys (NKDR). Residues of aerially 
applied naled were found 6 hours after application in a pineland area 
that was 820 yards (750 meters) from the target area; residues of 
fenthion (an adulticide no longer used in the Keys) applied via truck 
were found up to 55 yards (50 meters) downwind in a hammock area 15 
minutes after application in adjacent target areas (Hennessey et al. 
1992, pp. 715-721).
    More recently, Pierce (2009, pp. 1-17) monitored naled and 
permethrin deposition following application in and around NKDR from 
2007 to 2009. Permethrin, applied by truck, was found to drift 
considerable distances from target areas with residues that persisted 
for weeks. Naled, applied by plane, was also found to drift into 
nontarget areas but was much less persistent, exhibiting a half-life of 
approximately 6 hours. To expand this work, Pierce (2011, pp. 6-11) 
conducted an additional deposition study in 2010 focusing on permethrin 
drift from truck spraying and again documented measurable amounts of 
permethrin in nontarget areas. In 2009, Tim Bargar (pers. comm. 2011) 
conducted two field trials on NKDR that detected significant naled 
residues at locations within nontarget areas on the Refuge that were up 
to 440 yards (402 meters) from the edge of zones targeted for aerial 
applications.
    In addition to mosquito control chemicals entering nontarget areas, 
the toxic effects of mosquito control chemicals to nontarget organisms 
have also been documented. Lethal effects on nontarget Lepidoptera have 
been attributed to fenthion and naled in both south Florida and the 
Keys (Emmel 1991, pp. 12-13; Eliazar and Emmel 1991, pp. 18-19; Eliazar 
1992, pp. 29-30). In the lower Keys, Salvato (2001, pp. 8-14) suggested 
that declines in populations of the Florida leafwing (now a Federal 
candidate) were also partly attributable to mosquito control chemical 
applications. Salvato (2001, p. 14; 2002, pp. 56-57) found populations 
of the Florida leafwing (on Big Pine Key within NKDR) to increase 
during drier years when adulticide applications over the pinelands 
decreased, although Bartram's hairstreak did not follow this pattern. 
It is important to note that vulnerability to chemical exposure may 
vary widely between species, and current application regimes do not 
appear to affect some species as strongly as others (Calhoun et al. 
2002, p. 18; Breidenbaugh and De Szalay 2010, pp. 594-595; Rand and 
Hoang 2010, pp. 14-17, 20; Hoang et al. 2011, pp. 997-1005).
    Dose-dependent decreases in brain cholinesterase activity in great 
southern white butterflies (Ascia monuste) exposed to naled have been 
measured in the laboratory (T. Bargar, pers. comm. 2011). An inhibition 
of cholinesterase, which is the primary mode of action of naled, 
prevents an important neurotransmitter, acetylcholine, from being 
metabolized, causing uncontrolled nerve impulses that may result in 
erratic behavior and, if severe enough, mortality. From these data, it 
was determined that significant mortality was associated with 
cholinesterase activity depression of at least 27 percent (T. Bargar, 
pers. comm. 2011). In a subsequent field study on NKDR, adult great 
southern white and Gulf fritillary (Agraulis vanillae) butterflies were 
placed in field enclosures at both target and nontarget areas during 
aerial naled application. The critical level of cholinesterase 
inhibition (27 percent) was exceeded in the majority of butterflies 
from the target areas, as well as in a large proportion of butterflies 
from the nontarget areas (T. Bargar, pers. comm. 2011). During the same 
field experiment, great southern white and Gulf fritillary larvae were 
also exposed in the field during aerial naled application and exhibited 
mortality at both target and nontarget sites (T. Bargar, pers. comm. 
2011).
    In a laboratory study, Rand and Hoang (2010, pp. 1-33) and Hoang et 
al. (2011, pp. 997-1005) examined the effects of exposure to naled, 
permethrin, and dichlorvos (a breakdown product of naled) on both 
adults and larvae of five Florida native butterfly species (common 
buckeye (Junonia coenia), painted lady (Vanessa cardui), zebra longwing 
(Heliconius charitonius), atala hairstreak (Eumaeus atala), and white 
peacock (Anartia jatrophae). The results of this study indicated that, 
in general, larvae were slightly more sensitive to each chemical than 
adults, but the differences were not significant. Permethrin was 
generally the most toxic chemical to both larvae and adults, although 
the sensitivity between species varied.
    The laboratory toxicity data generated by this study were used to 
calculate hazard quotients (concentrations in the environment/
concentrations causing an

[[Page 20977]]

adverse effect) to assess the risk that concentrations of naled and 
permethrin found in the field pose to butterflies. A hazard quotient 
that exceeds one indicates that the environmental concentration is 
greater than the concentration known to cause an adverse effect 
(mortality in this case), thus indicating significant risk to the 
organism. Environmental exposures for naled and permethrin were taken 
from Zhong et al. (2010, pp. 1961-1972) and Pierce (2009, pp. 1-17), 
respectively, and represent the highest concentrations of each chemical 
that were quantified during field studies in the Keys. When using the 
lowest median lethal concentrations from the laboratory study, the 
hazard quotients for permethrin were greater than one for each adult 
butterfly, indicating a significant risk of toxicity to each species. 
In the case of naled, significant risk to the zebra longwing was 
predicted based on its hazard quotient exceeding one.
    In a recent study, Bargar (2012, pp. 1-7) conducted a probabilistic 
risk assessment for adult butterflies using published acute toxicity 
data in combination with deposition values for naled that were 
quantified at eight locations within NKDR. The published toxicity data 
were used in conjunction with morphometric data (total surface area and 
weight) for 22 butterfly species and the NKDR naled deposition values 
to estimate the probability that field exposure to naled will exceed 
butterfly effect estimates (quantity of naled per unit body weight 
associated with mortality in adult butterflies). From the field 
deposition measurements, the probability that the effect estimate for 
50 percent of the examined butterfly species will be exceeded ranged 
from 70 (lowest butterfly surface area to weight ratio) to 95 percent 
(highest surface area to weight ratio) based on filter paper deposition 
results and 33 to 87 percent based on yarn sampler results. As the 
surface area to weight ratio increases, the probability that a greater 
quantity of naled per unit body weight will be delivered increases. 
These results suggest that significant impacts on butterfly survival 
may result from aerial naled application.
    From 2006 to 2008, Zhong et al. (2010, pp. 1961-1972) investigated 
the impact of single aerial applications of naled on Miami blue larvae 
in the field. The study was conducted in North Key Largo in cooperation 
with the Florida Keys Mosquito Control District (FKMCD) and used 
experimentally placed Miami blue larvae that were reared in captivity. 
The study involved 15 test stations: 9 stations in the target zone, 3 
stations considered to be susceptible to drift (2 stations directly 
adjacent to the spray zone and 1 station 12 mi (19.3 km) southwest of 
the spray zone), and 3 field reference stations (25 mi (40.2 km) 
southwest of the spray zone). Survival of butterfly larvae in the 
target zone was 73.9 percent, which was significantly lower than both 
the drift zone (90.6 percent) and the reference zone (100 percent), 
indicating that direct exposure to naled poses significant risk to 
Miami blue larvae. In addition to observing elevated concentrations of 
naled at test stations in the target zone, 9 of 18 samples in the drift 
zone also exhibited detectable concentrations, once again exhibiting 
the potential for mosquito control chemicals to drift into nontarget 
areas.
    Based on these studies, it can be concluded that mosquito control 
activities that involve the use of both aerial and ground-based 
spraying methods have the potential to deliver pesticides in quantities 
sufficient to cause adverse effects to nontarget species in both target 
and nontarget areas. It should be noted that many of the studies 
referenced above dealt with single application scenarios and examined 
effects on only one to two butterfly life stages. Under a realistic 
scenario, the potential exists for exposure to all life stages to occur 
over multiple applications in a season. In the case of a persistent 
compound like permethrin where residues remain on vegetation for weeks, 
the potential exists for nontarget species to be exposed to multiple 
pesticides within a season (e.g., permethrin on vegetation coupled with 
aerial exposure to naled).
    Aspects of the Miami blue's natural history may increase its 
potential to be exposed to and affected by mosquito control pesticides 
and other chemicals. For example, host plants and nectar sources are 
commonly found at disturbed sites and often occur along roads in 
developed areas, where chemicals are applied. Ants associated with the 
Miami blue (see Interspecific relationships) may be affected in unknown 
ways. Host plant and nectar source availability may also be indirectly 
affected through impacts on pollinators. Carroll and Loye (2006, pp. 
19, 24) and others (Emmel 1991, p. 13; Glassberg and Salvato 2000, p. 
7; Calhoun et al. 2002, p. 18) suggested that the Miami blue butterfly 
may be more susceptible to pesticides than perhaps other lycaenids 
(e.g., the silver-banded hairstreak) because Miami blue larvae leave 
entrance holes open in seed pods to allow access for attending ants. 
Ants and larvae of the Miami blue on balloonvine were found to die when 
roadside spraying for mosquito control began in late spring, but larvae 
of the silver-banded hairstreak (also on balloonvine), who do not leave 
entrance holes in seed pods, apparently survived subsequent spraying 
(Emmel 1991, p. 13). However, Minno (pers. comm. 2010) argued that 
larvae using balloonvine pods would be protected from the effects of 
pesticides because the pods have internal partitions and exposure would 
be limited due to the size of the entrance hole.
    No mosquito control pesticides are used within KWNWR. At BHSP, the 
only application of adulticides (permethrin) is occasional truck-based 
spraying in the ranger residence areas (E. Kiefer, pers. comm. 2011a). 
Mosquito control practices currently pose no risk to the Miami blue 
within KWNWR. However, mosquito control activities, including the use 
of larvicides and adulticides, are being implemented within suitable 
and potential habitat for the Miami blue elsewhere in its range 
(Carroll and Loye 2006, pp. 14-15). The findings of Zhong et al. (2010, 
pp. 1961-1972) and Pierce (2009, pp. 1-17) along with other studies 
suggest that aerial or truck-based applications of mosquito control 
chemicals may pose a threat to the Miami blue, if the butterfly exists 
in other, unknown locations. Additionally, mosquito control practices 
potentially may limit expansion of undocumented populations or 
colonization of new areas. If the Miami blue colonizes new areas or if 
additional populations are discovered or reintroduced, adjustments in 
mosquito control (and other) practices may be needed to help safeguard 
the subspecies.
    Efforts are already underway by multiple agencies and partners to 
seek ways to avoid and minimize impacts to the Miami blue and other 
imperiled nontarget species. For example, in an effort to reduce the 
need for aerial adulticide spraying, the FKMCD is increasing 
larviciding activities, which are believed to have less of an 
ecological impact on wilderness islands near NKDR and GWHNWR (FKMCD 
2009, pp. 3-4). This effort has led to a reduction in area receiving 
adulticide treatment on Big Pine Key, No Name Key, and Torch Key (FKMCD 
2009, p. 17). Another example is the Florida Coordinating Council on 
Mosquito Control (FCCMC), including the Imperiled Species Subcommittee, 
which was initially formed to resolve the conflict between mosquito 
control spraying and the reintroduction of Miami blues to their 
historical range (FWC 2010, p. 9).
    The FWC's management plan for the Miami blue also recommended the 
use

[[Page 20978]]

of no-spray zones for all pesticides and use of buffers at or around 
Miami blue populations and other conservation measures (FWC 2010, pp. 
ii-41). However, there are no specific binding or mandatory 
restrictions to prohibit such practices or encourage other beneficial 
measures. The FWC plan suggested that an aerial no-spray buffer zone of 
820 yards (750 meters) be established around Miami blue populations, 
where possible, and that buffer zones for truck-based applications of 
adulticides also be established (FWC 2010, p. 17). The FCCMC also 
recommended that the appropriate width of buffer zones be determined by 
future research. The Service is supporting research to characterize 
drift from truck-based spraying methods. The data from this study will 
aid in better determining appropriate buffer distances around sensitive 
areas.
    In summary, although substantial progress has been made in reducing 
impacts, the potential effects of mosquito control applications and 
drift residues remain a threat to the Miami blue. We will continue to 
work with the mosquito control districts and other partners and 
stakeholders to reduce threats wherever possible.

Effects of Small Population Size and Isolation

    The Miami blue is vulnerable to extinction due to its severely 
reduced range, small population size, metapopulation structure, few 
remaining populations, and relative isolation. In general, isolation, 
whether caused by geographic distance, ecological factors, or 
reproductive strategy, will likely prevent the influx of new genetic 
material and can result in low diversity, which may impact viability 
and fecundity (Chesser 1983, pp. 66-77). Extinction risk can increase 
significantly with decreasing heterozygosity as was reported for the 
Glanville fritillary (Saccheri et al. 1998, pp. 491-494). Distance 
between metapopulations and colonies within those metapopulations and 
the small size of highly sporadic populations can make recolonization 
unlikely if populations are extirpated. Fragmentation of habitat and 
aspects of a butterfly's natural history (e.g., limited dispersal, 
reliance on host plants) can contribute to and exacerbate threats.
    Estimated abundance of the Miami blue is not known, but may number 
in the hundreds, and at times, possibly higher. Although highly 
dependent on individual species considered, a population of 1,000 has 
been suggested as marginally viable for an insect (D. Schweitzer, TNC, 
pers. comm. 2003). Schweitzer (pers. comm. 2003) has also suggested 
that butterfly populations of less than 200 adults per generation would 
have difficulty surviving over the long term. In comparison, in a 
review of 27 recovery plans for listed insect species, Schultz and 
Hammond (2003, p. 1377) found that 25 plans broadly specified 
metapopulation features in terms of requiring that recovery include 
multiple population areas (the average number of sites required was 
8.2). The three plans that quantified minimum population sizes as part 
of their recovery criteria for butterflies ranged from 200 adults per 
site (Oregon silverspot [Speyeria zerene hippolyta]) to 100,000 adults 
(Bay checkerspot [Euphydryas editha bayensis]) (Schulz and Hammond 
2003, pp. 1374-1375).
    Schultz and Hammond (2003, pp. 1372-1385) used population viability 
analyses to develop quantitative recovery criteria for insects whose 
population sizes can be estimated and applied this framework in the 
context of the Fender's blue (Icaricia icarioides fenderi), a butterfly 
listed as endangered in 2000 due to its small population size and 
limited remaining habitat. They found the Fender's blue to be at high 
risk of extinction at most of its sites throughout its range despite 
that fact that the average population at 12 sites examined ranged from 
5 to 738 (Schulz and Hammond 2003, pp. 1377, 1379). Of the three sites 
with populations greater than a few hundred butterflies, only one of 
these had a reasonably high probability of surviving the next 100 years 
(Schulz and Hammond 2003, p. 1379). Although the conservation needs and 
biology of the Miami blue and Fender's blue are undoubtedly different, 
the two lycaenids share characteristics: Both have limited dispersal, 
and most remaining habitat patches are completely isolated.
    Losses in diversity within historical and current populations of 
the Miami blue butterfly have already occurred. Historical populations 
were genetically more diverse than two contemporary populations (BHSP 
and KWNWR) (Saarinen 2009, p. 48). Yet together, between the two 
contemporary populations, the Miami blue had retained a significant 
amount of genetic diversity from its historical values (Saarinen 2009, 
p. 51). Despite likely fluctuations in population size, the BHSP 
population had retained an adequate amount of genetic diversity to 
maintain the population (Saarinen 2009, p. 77). Overall, patterns of 
genetic diversity in the BHSP population (mean overall observed 
heterozygosity of 39.5 percent) were similar to or slightly lower than 
other nonmigratory butterfly species studies utilizing microsatellite 
markers (Saarinen 2009, pp. 50, 74-75). Unfortunately, the BHSP 
population may now be lost. The extant KWNWR population is more 
genetically diverse (mean observed heterozygosity of 51 percent vs. 
39.5 percent for BHSP) (Saarinen 2009, p. 75).
    The Miami blue appears to have been impacted by relative isolation. 
No gene flow has occurred between contemporary populations (Saarinen et 
al. 2009a, p. 36). Saarinen (2009, p. 79) suggested that the separation 
was recent. While historical populations may have once linked the two 
contemporary populations, the recent absence of populations between 
KWNWR and BHSP appears to have broken the gene flow (Saarinen 2009, p. 
79). Based upon modeling with a different butterfly species, Fleishman 
et al. (2002, pp. 706-716) argued that factors such as habitat quality 
may influence metapopulation dynamics, driving extinction and 
colonization processes, especially in systems that experience 
substantial natural and anthropogenic environmental variability (see 
Environmental Stochasticity below).
    According to Saarinen et al. (2009a, p. 36), the severely reduced 
size of the existing populations suggests that genetic factors, along 
with environmental stochasticity, may already be affecting the 
persistence of the Miami blue. However, they also suggested that, in 
terms of extinction risk, a greater short-term problem for the two 
contemporary natural populations (BHSP and KWNWR) may be the lack of 
gene flow rather than the current effective population size (Saarinen 
et al. 2009a, p. 36). If only one or two metapopulations remain, it is 
absolutely critical that remaining genetic diversity and gene flow are 
retained. Conservation decisions to augment or reintroduce populations 
should not be made without careful consideration of habitat 
availability, genetic adaptability, the potential for the introduction 
of maladapted genotypes, and other factors (Frankham 2008, pp. 325-333; 
Saarinen et al. 2009a, p. 36).

Aspects of Its Natural History

    Aspects of the Miami blue's natural history may increase the 
likelihood of extinction. Cushman and Murphy (1993, p. 40) argued that 
dispersal is essential for the persistence of isolated populations. 
Input of individuals from neighboring areas can bolster dwindling 
numbers and provide an influx of genetic diversity, increasing fitness 
and population viability. The tendency for

[[Page 20979]]

lycaenids to be comparatively sedentary should result in less frequent 
recolonization, less influx of individuals, and reduced gene flow 
between populations (Cushman and Murphy 1993, p. 40). In short, taxa 
with limited dispersal abilities may be far more susceptible to local 
extinction events than taxa with well-developed dispersal abilities 
(Cushman and Murphy 1993, p. 40).
    Lycaenids with a strong dependence on ants may be more sensitive to 
environmental changes and, thus, more prone to endangerment and 
extinction than species not tended by ants (and non-lycaenids in 
general) (Cushman and Murphy 1993, pp. 37, 41). This hypothesis is 
based on the probability that the combination of both the right food 
plant and the presence of a particular ant species may occur relatively 
infrequently in the landscape. Selection may favor reduced dispersal by 
ant-associated lycaenids due to the difficulty associated with locating 
patches that contain the appropriate combination of food plants and 
ants (Cushman and Murphy 1993, pp. 39-40). Although significant 
research on the relationship between Miami blue larvae and ants has 
been conducted, this association is still not completely understood. 
Lycaenid traits (sedentary, host-specific, symbiotic with ants) that 
result in isolated populations of variable sizes may serve to limit 
genetic exchange (Cushman and Murphy 1993, pp. 37, 39-40). The Miami 
blue possesses several of these traits, all of which may increase 
susceptibility and contribute to imperilment.

Environmental Stochasticity

    The climate of the Keys is driven by a combination of local, 
regional, and global events, regimes, and oscillations. There are three 
main ``seasons'': (1) The wet season, which is hot, rainy, and humid 
from June through October, (2) the official hurricane season that 
extends one month beyond the wet season (June 1 through November 30) 
with peak season being August and September, and (3) the dry season, 
which is drier and cooler from November through May. In the dry season, 
periodic surges of cool and dry continental air masses influence the 
weather with short-duration rain events followed by long periods of dry 
weather.
    Environmental factors have likely impacted the Miami blue and its 
habitat within its historical range. A hard freeze in the late 1980s 
likely contributed to the Miami blue's decline (L. Koehn, pers. comm. 
2002), presumably due to loss of larval host plants in south Florida. 
Prolonged cold temperatures in January 2010 and December 2010 through 
January 2011 may have also impacted the remaining metapopulations in 
the Keys. Unseasonably cold temperatures during winter 2010 (in 
combination with impacts from iguanas) resulted in a substantial loss 
of nickerbean and nectar sources at BHSP. This reduction, albeit 
temporary, may have severely impacted an already depressed Miami blue 
population on the island. Similarly, extended dry conditions and 
drought can affect the availability of host plants and nectar sources 
and affect butterfly populations (Emmel and Daniels 2004, pp. 13-14, 
17). Depressed numbers of the Miami blue at BHSP in 2008 were 
attributed to severe drought (Emmel and Daniels 2009, p. 4).
    The Keys are regularly threatened by tropical storms and 
hurricanes. No area of the Keys is more than 20 feet (6.1 meters) above 
sea level (and many areas are only a few feet (meters) in elevation). 
These tropical systems have affected the Miami blue and its habitat. 
Calhoun et al. (2002, p. 18) indicated that Hurricane Andrew in 1992 
may have negatively impacted the majority of Miami blue populations in 
southern Florida. In 2005, four hurricanes (Katrina, Dennis, Rita, and 
Wilma) affected habitat at BHSP, resulting in reduced abundance of 
Miami blues following the storms that continued throughout 2006 
(Salvato and Salvato 2007, p. 160) and beyond (Emmel and Daniels 2009, 
p. 4). A significant portion of the nickerbean and large stands of 
nectar plants at BHSP were temporarily damaged by the storms, including 
roughly 50 percent of the vegetation on the southern side of the island 
(Salvato and Salvato 2007, p. 157). Although the host plant quickly 
recovered following the storms (Salvato and Salvato 2007, p. 160), the 
Miami blue never fully recolonized several parts of the island (Emmel 
and Daniels 2009, p. 4).
    Similarly, Hurricane Wilma heavily damaged blackbead across many 
islands within KWNWR (Cannon et al. 2010, p. 850). Although the 
hurricane severely damaged or killed much of the Miami blue host plant 
on KWNWR, it is also believed to have enhanced or created many new 
habitats across the islands by clearing older vegetation and opening 
patches for growth of host plant and nectar sources (Cannon et al. 
2010, p. 852). Cannon et al. (2010, p. 852) suggested that the 
proximity and circular arrangement of these islands may provide some 
safeguard during mild or moderate storms. Given enough resiliency in 
extant populations, certain storm regimes may benefit populations over 
some timeframe if these events result in disturbances that favor host 
plants and other habitat components.
    According to the Florida Climate Center, Florida is by far the most 
vulnerable State in the United States to hurricanes and tropical storms 
(http://coaps.fsu.edu/climate_center/tropicalweather.shtml). Based on 
data gathered from 1856 to 2008, Klotzbach and Gray (2009, p. 28) 
calculated the climatological and current-year probabilities for each 
State being impacted by a hurricane and major hurricane. Of the coastal 
States analyzed, Florida had the highest climatological probabilities, 
with a 51 percent probability of a hurricane and a 21 percent 
probability of a major hurricane over a 52-year time span. Florida had 
a 45 percent current-year probability of a hurricane and an 18 percent 
current-year probability of a major hurricane (Klotzbach and Gray 2009, 
p. 28). Given the Miami blue's low population size and few isolated 
occurrences, the subspecies is at substantial risk from hurricanes, 
storm surges, or other extreme weather. Depending on the location and 
intensity of a hurricane or other severe weather event, it is possible 
that the Miami blue could become extirpated or extinct. Because it 
appears to have limited dispersal capabilities, natural recolonization 
of potentially suitable sites is anticipated to be unlikely or 
exceedingly slow at best.
    Other processes to be affected by climate change include 
temperatures, rainfall (amount, seasonal timing, and distribution), and 
storms (frequency and intensity). Temperatures are projected to rise 
from 2 [deg]C to 5 [deg]C (3.6 [deg]F to 9 [deg]F) for North America by 
the end of this century (IPCC 2007, pp. 7-9, 13). Based upon modeling, 
Atlantic hurricane and tropical storm frequencies are expected to 
decrease (Knutson et al. 2008, pp. 1-21). By 2100, there should be a 
10-30 percent decrease in hurricane frequency with a 5-10 percent wind 
increase. This is due to more hurricane energy available for intense 
hurricanes. However, hurricane frequency is expected to drop due to 
more wind shear impeding initial hurricane development. In addition to 
climate change, weather variables are extremely influenced by other 
natural cycles, such as El Ni[ntilde]o Southern Oscillation with a 
frequency of every 4-7 years, solar cycle (every 11 years), and the 
Atlantic Multi-decadal Oscillation. All of these cycles influence 
changes in Floridian weather. The exact magnitude, direction, and 
distribution of all of these changes at the regional level are 
difficult to project.

[[Page 20980]]

Summary of Factor E
    Based on our analysis of the best available information we have 
identified a wide array of natural and manmade factors affecting the 
continued existence of the Miami blue butterfly. Effects of small 
population size, isolation, and loss of genetic diversity are likely 
significant threats. Aspects of the Miami blue's natural history and 
environmental stochasticity may also contribute to its imperilment. 
Other natural (e.g., impacts from iguanas, changes to habitat, invasive 
and exotic vegetation) and anthropogenic factors (e.g., pesticides, 
habitat alteration, impacts from humans) are also identifiable threats. 
Collectively, these threats have operated in the past, are impacting 
the subspecies now, and will continue to impact the Miami blue in the 
future.

Determination of Status

    We have carefully assessed the best scientific and commercial 
information available regarding the past, present, and future threats 
to the Miami blue butterfly. The only confirmed metapopulation of Miami 
blue is currently restricted to a few, small insular areas in the 
extreme southern portion of its historical range. The butterfly's 
range, which once extended from the Keys north along the Florida coasts 
to about St. Petersburg and Daytona, is now substantially reduced, with 
an estimated >99 percent decline in area occupied. Many factors likely 
contributed to the Miami blue's decline, and numerous major threats, 
acting individually or synergistically, continue today (see Summary of 
Factors Affecting the Species).
    Habitat loss, degradation, and modification from human population 
growth and associated development and agriculture have impacted the 
Miami blue, curtailing its range (see Factor A). Environmental effects 
from climatic change, especially sea level rise, are expected to become 
severe in the future, resulting in additional habitat losses (see 
Factor A). Due to the few metapopulations, small population size, 
restricted range, and remoteness of occupied habitat, collection is a 
significant threat to the subspecies and could potentially occur at any 
time (see Factor B). Even limited collection from the remaining 
metapopulation could have deleterious effects on reproductive and 
genetic viability of the subspecies and could contribute to its 
extinction. Similarly, disease and predation (see Factor C) also have 
the potential to impact the Miami blue's continued survival, given its 
vulnerability (see Factor E).
    The subspecies is currently also threatened by a wide array of 
natural and manmade factors (see Factor E). In addition to the effects 
of small population size, isolation, and loss of genetic diversity, 
aspects of the Miami blue's natural history and environmental 
stochasticity may contribute to its imperilment. Other natural (e.g., 
impacts from iguanas, changes to habitat) and anthropogenic factors 
(e.g., pesticides, impacts from humans) are also threats of varying 
magnitude. Finally, existing regulatory mechanisms (see Factor D), due 
to a variety of constraints, do not work as designed and do not provide 
adequate protection for the subspecies. Overall, impacts from 
increasing threats, operating singly or in combination, are likely to 
result in the extinction of the subspecies.
    Section 3 of the Endangered Species Act defines an endangered 
species as ``* * * any species which is in danger of extinction 
throughout all or a significant portion of its range'' and a threatened 
species as ``* * * any species which is likely to become an endangered 
species within the foreseeable future throughout all or a significant 
portion of its range.'' Based on the immediate and ongoing significant 
threats to the Miami blue butterfly throughout its entire occupied 
range and the fact that the subspecies is restricted to only one or 
possibly two populations, we have determined that the subspecies is in 
danger of extinction throughout all of its range. Since threats extend 
throughout the entire range, it is unnecessary to determine if the 
Miami blue butterfly is in danger of extinction throughout a 
significant portion of its range. Therefore, on the basis of the best 
available scientific and commercial information, we have determined 
that the Miami blue butterfly meets the definition of an endangered 
species under the Act. Consequently, we are listing the Miami blue 
butterfly as an endangered species throughout its entire range.
    The survival of the Miami blue now depends on protecting the 
species' occupied and suitable habitat from further degradation and 
fragmentation, removing and reducing controllable threats, increasing 
the current population in size, reducing the threats of illegal 
collection, retaining the remaining genetic diversity; and establishing 
populations at additional locations. The survey and monitoring efforts 
and scientific studies conducted to date, when combined with other 
available historical information, indicate that the Miami blue 
butterfly is on the brink of extinction.
    By listing the Miami blue butterfly as an endangered subspecies, 
the protections (through sections 7, 9, and 10 of the Act) and 
recognition that immediately became available to the subspecies upon 
emergency listing will continue and increase the likelihood that it can 
be saved from extinction and ultimately be recovered. In addition, 
recovery funds may become available, which could facilitate recovery 
actions (e.g., funding for additional surveys, management needs, 
research, captive propagation and reintroduction, monitoring) (see 
Available Conservation Measures, below).
    The Service acknowledges that it cannot fully address some of the 
natural threats facing the subspecies (e.g., hurricanes, tropical 
storms) or even some of the other significant, long-term threats (e.g., 
climatic changes, sea-level rise). However, through listing, we provide 
protection to the known population(s) and any new population of the 
subspecies that may be discovered (see section 9 of Available 
Conservation Measures, below). With listing, we can also influence 
Federal actions that may potentially impact the subspecies (see section 
7 below); this is especially valuable if it is found at additional 
locations. With this action, we are also better able to deter illicit 
collection and trade.
    Through this action, the Miami blue will continue receiving 
protection from collection, possession, and trade (through sections 9 
and 10 of the Act). The three butterflies that are similar in 
appearance to the Miami blue will receive protection from collection in 
portions of their ranges (i.e., portions that overlap with the Miami 
blue's historical range). At present, the three similar butterflies are 
not protected by the State of Florida. Extending the prohibitions of 
collection to the three similar butterflies in portions of their ranges 
provides greater protection to the Miami blue. Listing will partially 
alleviate some of the imminent threats that now pose a significant risk 
to the survival of the subspecies.

Critical Habitat and Prudency Determination

    Critical habitat is defined in section 3(5)(A) of the Act as (i) 
the specific areas within the geographic area occupied by a species, at 
the time it is listed in accordance with the Act, on which are found 
those physical or biological features (I) essential to the conservation 
of the species and (II) that may require special management 
considerations or protection; and (ii) specific areas

[[Page 20981]]

outside the geographic area occupied by a species at the time it is 
listed, upon a determination that such areas are essential for the 
conservation of the species. Conservation is defined in section 3(3) of 
the Act as the use of all methods and procedures that are necessary to 
bring any endangered or threatened species to the point at which 
listing under the Act is no longer necessary.
    Section 4(a)(3) of the Act, as amended, and implementing 
regulations (50 CFR 424.12), require that, to the maximum extent 
prudent and determinable, we designate critical habitat at the time we 
determine that a species is endangered or threatened. Our regulations 
(50 CFR 424.12(a)(1)) state that the designation of critical habitat is 
not prudent when one or both of the following situations exist: (1) The 
species is threatened by taking or other human activity, and 
identification of critical habitat can be expected to increase the 
degree of threat to the species, or (2) such designation of critical 
habitat would not be beneficial to the species. We have determined that 
both circumstances apply to the Miami blue butterfly. This 
determination involves a weighing of the expected increase in threats 
associated with a critical habitat designation against the benefits 
gained by a critical habitat designation. An explanation of this 
``balancing'' evaluation follows.

Benefits to the Subspecies From Critical Habitat Designation

    The principal benefit of including an area in a critical habitat 
designation is the requirement for Federal agencies to ensure actions 
they fund, authorize, or carry out are not likely to result in the 
destruction or adverse modification of any designated critical habitat, 
the regulatory standard of section 7(a)(2) of the Act under which 
consultation is completed. Federal agencies must also consult with us 
on actions that may affect a listed species and refrain from 
undertaking actions that are likely to jeopardize the continued 
existence of such species. The analysis of effects of a proposed 
project on critical habitat is separate and different from that of the 
effects of a proposed project on the species itself. The jeopardy 
analysis evaluates the action's impact to survival and recovery of the 
species, while the destruction or adverse modification analysis 
evaluates the action's effects to the designated habitat's contribution 
to conservation. Therefore, the difference in outcomes of these two 
analyses represents the regulatory benefit of critical habitat. This 
will, in some instances, lead to different results and different 
regulatory requirements. Thus, critical habitat designations may 
provide greater benefits to the recovery of a species than would 
listing alone.
    All areas known to support the Miami blue butterfly since 1996 are 
or have been on Federal or State lands; these areas are currently being 
managed for the subspecies. Management efforts are consistent with, and 
geared toward, Miami blue conservation, and such efforts are expected 
to continue in the future. Because the butterfly exists only as one or 
possibly two small metapopulations, any future activity involving a 
Federal action that would destroy or adversely modify occupied critical 
habitat may also likely jeopardize the subspecies' continued existence 
(see Jeopardy Standard, below). Consultation with respect to critical 
habitat would provide additional protection to a species only if the 
agency action would result in the destruction or adverse modification 
of the critical habitat but would not jeopardize the continued 
existence of the species. In the absence of a critical habitat 
designation, areas that support the Miami blue butterfly will continue 
to be subject to conservation actions implemented under section 7(a)(1) 
of the Act and to the regulatory protections afforded by the section 
7(a)(2) jeopardy standard, as appropriate. Federal actions affecting 
the Miami blue butterfly, even in the absence of designated critical 
habitat areas, will still benefit from consultation pursuant to section 
7(a)(2) of the Act and may still result in jeopardy findings. 
Therefore, designation of specific areas as critical habitat that are 
currently occupied or recently occupied would not likely provide a 
measurable incremental benefit to the subspecies.
    Another potential benefit to the Miami blue butterfly from 
designating critical habitat is that it could serve to educate 
landowners, State and local government agencies, Refuge or Park 
visitors, and the general public regarding the potential conservation 
value of the area. Through the processes of listing the butterfly under 
the State of Florida's endangered species statute in 2002, the 
recognition of the Miami blue as a Federal candidate subspecies in 
2005, and our proposed and emergency rules for the subspecies in August 
2011, much of this educational component is already in effect. 
Agencies, organizations, and stakeholders are actively engaged in 
efforts to raise awareness for the butterfly and its conservation 
needs. For example, the NABA has a Miami blue chapter, which helps 
promote awareness for the subspecies. The FWC and partners have also 
formed a workgroup, in part to raise awareness for imperiled 
butterflies in south Florida. Staff at BHSP have recruited volunteers 
to help search for the subspecies within the Park and surrounding 
areas, and they have organized speakers to inform the general public 
about the butterfly. In addition, designation of critical habitat could 
inform State agencies and local governments about areas that could be 
conserved under State laws or local ordinances. However, since 
awareness and education involving the Miami blue is already well 
underway, designation of critical habitat would likely provide only 
minimal incremental educational benefits.

Increased Threat to the Subspecies by Designating Critical Habitat

    Designation of critical habitat requires the publication of maps 
and a narrative description of specific critical habitat areas in the 
Federal Register. The degree of detail in those maps and boundary 
descriptions is greater than the general location descriptions provided 
in this rule listing the species as endangered. At present, maps 
depicting the locations of extant populations and habitat most likely 
to support the Miami blue do not exist. We are concerned that 
designation of critical habitat would more widely announce the exact 
location of the butterflies (and highly suitable habitat) to poachers, 
collectors, and vandals and further facilitate unauthorized collection 
and trade. Due to its extreme rarity (a low number of individuals, 
combined with small areas inhabited by the remaining metapopulation), 
this butterfly is highly vulnerable to collection. Vandalism, 
disturbance, and other harm from humans are also serious threats to the 
butterfly and its habitat (see Factors B and E above). At this time, 
removal of any individuals or damage to habitat may have devastating 
consequences for the survival of the subspecies. We estimate that these 
threats would be exacerbated by the publication of maps and 
descriptions outlining the specific locations of this critically 
imperiled butterfly in the Federal Register and local newspapers. Maps 
and descriptions of critical habitat, such as those that would appear 
in the Federal Register if critical habitat were designated, are not 
now available to the general public.
    Although we do not have specific evidence of taking for this 
subspecies, illegal collection of imperiled butterflies from State, 
Federal, and other lands in Florida appears ongoing, prevalent, and 
damaging (see Factor B analysis above). In addition, we are aware that 
a market

[[Page 20982]]

exists for trade in rare, imperiled, and listed butterflies, including 
those in south Florida (see Factor B analysis above).
    Additionally, we are aware of a market for butterflies that look 
similar to the Miami blue, including all three of the subspecies we are 
listing due to similarity of appearance (see above), as well as other 
Cyclargus thomasi subspecies that occur in foreign countries. It is 
clear that a demand currently exists for both imperiled butterflies and 
those similar in appearance to the Miami blue. Due to its few 
metapopulations, small population size, restricted range, and 
remoteness of occupied habitat, we find that collection is a 
significant threat to the Miami blue butterfly and could occur at any 
time. Even limited collection from the remaining population (or other 
populations, if discovered) could have deleterious effects on 
reproductive and genetic viability and thus could contribute to its 
extinction. Identification of critical habitat would increase the 
severity of this threat by depicting the exact locations where the 
subspecies may be found and more widely publicizing detailed 
information and maps, exposing the fragile population to greater risks.
    Identification and publication of critical habitat may also 
increase the likelihood of inadvertent or purposeful habitat 
destruction. Damage to host plants from humans has been documented in 
the past (see Factor E above). Recreation within occupied areas has 
resulted in trampling of vegetation and negative impacts to the 
subspecies and its habitat (see Factor E above). High visitation and 
illicit uses (e.g., fire pits, camping, vandalism) within occupied and 
suitable habitat have resulted in local disturbances, and the risk of 
fire (natural or human-induced) is now a significant threat (see Factor 
E above). In addition, some private property owners in the Keys have 
reportedly threatened to clear vegetation from undeveloped properties 
to avoid any restrictions regarding the butterfly (M. Minno, in litt. 
2011b; N. Pakhomoff-Spencer, consultant, pers. comm. 2011). We 
recognize that landowner cooperation is key to the Miami blue's 
survival and recovery; however, this may be reduced with critical 
habitat designation. We estimate that identification and advertisement 
of critical habitat may exacerbate these threats, thus making sensitive 
areas more vulnerable to purposeful harmful impacts from humans. 
Immature stages (eggs, larvae), which are sedentary, are particularly 
vulnerable. Overall, identification and publication of detailed 
critical habitat information and maps would likely increase exposure of 
sensitive habitats and increase the likelihood and severity of threats 
to both the subspecies and its habitat.
    Identification and publication of critical habitat may lead to 
increased attention to the subspecies, or increased attempts to 
illegally collect it, which could also lead to an increase in 
enforcement problems. Although take prohibitions exist, effective 
enforcement is difficult. As discussed in Factors B, D, and E and 
elsewhere above, the threat of collection and inadvertent impacts from 
humans exists; areas are already difficult to patrol. Areas within the 
KWNWR are remote and accessible mainly by boat, making them difficult 
for law enforcement personnel to patrol and monitor. Designation of 
critical habitat would facilitate further use and misuse of sensitive 
habitats and resources, creating additional difficulty for law 
enforcement personnel in an already challenging environment.
    Overall, we find that designation of critical habitat will increase 
the likelihood and severity of the threats of illegal collection of the 
subspecies and destruction of sensitive habitat. With increased 
attention and activities, we also anticipate that designation will 
contribute to, and exacerbate enforcement issues and problems.

Increased Threat to the Subspecies Outweighs the Benefits of Critical 
Habitat Designation

    Upon reviewing the available information, we have determined that 
the designation of critical habitat would subject the subspecies to 
increased threats, while conferring little additional incremental 
benefit beyond that provided by listing. With designation, minor 
regulatory (e.g., consulting on adverse modifications) and educational 
benefits may be realized. However, these benefits (beyond listing) will 
be more than offset by the increased threats to the subspecies and its 
habitat that could be associated with critical habitat designation.
    Critical habitat involves the identification and publication of 
detailed descriptions and maps. Publication of such maps and 
information, otherwise not now available, exposes the Miami blue to an 
increased threat of collection. It also increases the potential for 
inadvertent or purposeful disturbance and vandalism to important and 
sensitive habitats and contributes to enforcement issues. Overall, we 
find that the risk of increasing significant threats to the subspecies 
by publishing location information in a critical habitat designation 
greatly outweighs the minimal regulatory and educational benefits of 
designating critical habitat.
    In conclusion, we find that the designation of critical habitat is 
not prudent, in accordance with 50 CFR 424.12(a)(1), because the Miami 
blue butterfly is threatened by collection and habitat destruction, and 
designation can reasonably be expected to increase the degree of these 
threats to the subspecies and its habitat.

Available Conservation Measures

    Conservation measures provided to species listed as endangered or 
threatened under the Act include recognition, recovery actions, 
requirements for Federal protection, and prohibitions against certain 
practices. Recognition through listing results in public awareness and 
conservation by Federal, State, Tribal, and local agencies, private 
organizations, and individuals. The Act encourages cooperation with the 
States and requires that recovery actions be carried out for all listed 
species. The protection required by Federal agencies and the 
prohibitions against certain activities are discussed, in part, below.
    The primary purpose of the Act is the conservation of endangered 
and threatened species and the ecosystems upon which they depend. The 
ultimate goal of such conservation efforts is the recovery of these 
listed species, so that they no longer need the protective measures of 
the Act. Subsection 4(f) of the Act requires the Service to develop and 
implement recovery plans for the conservation of endangered and 
threatened species. The recovery planning process involves the 
identification of actions that are necessary to halt or reverse the 
species' decline by addressing the threats to its survival and 
recovery. The goal of this process is to restore listed species to a 
point where they are secure, self-sustaining, and functioning 
components of their ecosystems.
    Recovery planning includes the development of a recovery outline 
shortly after a species is listed, preparation of a draft and final 
recovery plan, and revisions to the plan as significant new information 
becomes available. The recovery outline guides the immediate 
implementation of urgent recovery actions and describes the process to 
be used to develop a recovery plan. The recovery plan identifies site-
specific management actions that will achieve recovery of the species, 
measurable criteria that determine when a species may be downlisted or 
delisted, and methods for monitoring recovery

[[Page 20983]]

progress. Recovery plans also establish a framework for agencies to 
coordinate their recovery efforts and provide estimates of the cost of 
implementing recovery tasks. Recovery teams (composed of species 
experts, Federal and State agencies, nongovernmental organizations, and 
stakeholders) are often established to develop recovery plans. When 
completed, the draft recovery plan, and the final recovery plan will be 
available on our Web site (http://www.fws.gov/endangered), or from our 
South Florida Ecological Services Field Office (see FOR FURTHER 
INFORMATION CONTACT).
    Implementation of recovery actions generally requires the 
participation of a road range of partners, including other Federal 
agencies, States, Tribes, nongovernmental organizations, businesses, 
and private landowners. Examples of recovery actions include habitat 
restoration (e.g., restoration of native vegetation), research, captive 
propagation and reintroduction, and outreach and education. The 
recovery of many listed species cannot be accomplished solely on 
Federal lands because their range may occur primarily or solely on non-
Federal lands. Achieving recovery of these species requires cooperative 
conservation efforts on private, State, and Tribal lands.
    Through this listing, funding for recovery actions will be 
available from a variety of sources, including Federal budgets, State 
programs, and cost share grants for non-Federal landowners, the 
academic community, and nongovernmental organizations. Additionally, 
under section 6 of the Act, we would be able to grant funds to the 
State of Florida for management actions promoting the conservation of 
the Miami blue. Information on our grant programs that are available to 
aid species recovery can be found at: http://www.fws.gov/grants.
    Please let us know if you are interested in participating in 
recovery efforts for the Miami blue. Additionally, we invite you to 
submit any new information on the subspecies, its habitat, or threats 
whenever it becomes available and any information you may have for 
recovery planning purposes.
    Section 7(a) of the Act requires Federal agencies to evaluate their 
actions with respect to any species that is proposed or listed as 
endangered or threatened and with respect to its critical habitat, if 
any is being designated. Regulations implementing this interagency 
cooperation provision of the Act are codified at 50 CFR part 402. 
Section 7(a)(4) requires Federal agencies to confer informally with us 
on any action that is likely to jeopardize the continued existence of a 
species proposed for listing or result in destruction or adverse 
modification of proposed critical habitat. If a species is listed 
subsequently, section 7(a)(2) of the Act requires Federal agencies to 
ensure that activities they authorize, fund, or carry out are not 
likely to jeopardize the continued existence of such a species or to 
destroy or adversely modify its critical habitat. If a Federal action 
may affect a listed species or its critical habitat, the responsible 
Federal agency must enter into formal consultation with us.
    Federal agency actions that may require conference or consultation 
as described in the preceding paragraph include the issuance of Federal 
funding, permits, or authorizations for construction, clearing, 
development, road maintenance, pesticide registration, pesticide use 
(on Federal land or with Federal funding), agricultural assistance 
programs, Federal loan and insurance programs, Federal habitat 
restoration programs, and scientific and special uses. Activities will 
trigger consultation under section 7 of the Act if they may affect the 
Miami blue butterfly.

Jeopardy Standard

    Prior to and following listing, the Service applies an analytical 
framework for jeopardy analyses that relies heavily on the importance 
of core area populations to the survival and recovery of the species. 
The section 7(a)(2) analysis is focused not only on these populations 
but also on the habitat conditions necessary to support them.
    The jeopardy analysis usually expresses the survival and recovery 
needs of the species in a qualitative fashion without making 
distinctions between what is necessary for survival and what is 
necessary for recovery. Generally, if a proposed Federal action is 
incompatible with the viability of the affected core area 
populations(s), inclusive of associated habitat conditions, a jeopardy 
finding is considered to be warranted, because of the relationship of 
each core area population to the survival and recovery of the species 
as a whole.

Section 9 Take

    The Act and implementing regulations set forth a series of general 
prohibitions and exceptions that apply to all endangered and threatened 
wildlife. These prohibitions are applicable to the Miami blue butterfly 
immediately with listing. The prohibitions of section 9(a)(2) of the 
Act, codified at 50 CFR 17.21 for endangered wildlife, in part, make it 
illegal for any person subject to the jurisdiction of the United States 
to take (includes harass, harm, pursue, hunt, shoot, wound, kill, trap, 
capture, or collect, or to attempt any of these), import or export, 
deliver, receive, carry, transport, or ship in interstate or foreign 
commerce in the course of commercial activity, or sell or offer for 
sale in interstate or foreign commerce any listed species. It also is 
illegal to possess, sell, deliver, carry, transport, or ship any such 
wildlife that has been taken illegally. Further, it is illegal for any 
person to attempt to commit, to solicit another person to commit, or to 
cause to be committed, any of these acts. Certain exceptions apply to 
our agents and State conservation agencies.
    We may issue permits to carry out otherwise prohibited activities 
involving endangered wildlife under certain circumstances. We codified 
the regulations governing permits for endangered species at 50 CFR 
17.22. Such permits are available for scientific purposes, to enhance 
the propagation or survival of the species, or for incidental take in 
the course of otherwise lawful activities.
    It is our policy, published in the Federal Register on July 1, 1994 
(59 FR 34272), to identify, to the maximum extent practicable at the 
time a species is listed, those activities that would or would not 
constitute a violation of section 9 of the Act and associated 
regulations at 50 CFR 17.21. The intent of this policy is to increase 
public awareness of the effect of this final listing on proposed and 
ongoing activities within a species' range. We estimate, based on the 
best available information, that the following actions will not result 
in a violation of the provisions of section 9 of the Act, provided 
these actions are carried out in accordance with existing regulations 
and permit requirements, if applicable:
    (1) Possession, delivery, or movement, including interstate 
transport and import into or export from the United States, involving 
no commercial activity, of dead specimens of this taxon that were 
collected or legally acquired prior to the effective date of the 
emergency rule (August 10, 2011).
    (2) Actions that may affect the Miami blue that are authorized, 
funded, or carried out by Federal agencies when such activities are 
conducted in accordance with an incidental take statement issued by us 
under section 7 of the Act.
    (3) Actions that may affect the Miami blue that are not authorized, 
funded, or carried out by a Federal agency, when the action is 
conducted in accordance with an incidental take permit issued by

[[Page 20984]]

us under section 10(a)(1)(B) of the Act. Applicants design a Habitat 
Conservation Plan (HCP) and apply for an incidental take permit. These 
HCPs are developed for species listed under section 4 of the Act and 
are designed to minimize and mitigate impacts to the species to the 
maximum extent practicable.
    (4) Actions that may affect the Miami blue that are conducted in 
accordance with the conditions of a section 10(a)(1)(A) permit for 
scientific research or to enhance the propagation or survival of the 
subspecies.
    (5) Captive propagation activities involving the Miami blue that 
are conducted in accordance with the conditions of a section 
10(a)(1)(A) permit, our ``Policy Regarding Controlled Propagation of 
Species Listed Under the Endangered Species Act,'' and in cooperation 
with the State of Florida.
    (6) Low-impact, infrequent, dispersed human activities on foot 
(e.g., bird watching, butterfly watching, sightseeing, backpacking, 
photography, camping, hiking) in areas occupied by the Miami blue or 
where its host and nectar plants are present.
    (7) Activities on private lands that do not result in take of the 
Miami blue butterfly, such as normal landscape activities around a 
personal residence, construction that avoids butterfly habitat, and 
pesticide/herbicide application consistent with label restrictions, if 
applied in areas where the subspecies is absent.
    We estimate that the following activities would be likely to result 
in a violation of section 9 of the Act; however, possible violations 
are not limited to these actions alone:
    (1) Unauthorized possession, collecting, trapping, capturing, 
killing, harassing, sale, delivery, or movement, including interstate 
and foreign commerce, or harming or attempting any of these actions, of 
Miami blue butterflies at any life stage without a permit (research 
activities where Miami blue butterflies are handled, captured (e.g., 
netted, trapped), marked, or collected will require a permit under 
section 10(a)(1)(A) of the Act).
    (2) Incidental take of Miami blue butterfly without a permit 
pursuant to section 10 (a)(1)(B) of the Act.
    (3) Sale or purchase of specimens of this taxon, except for 
properly documented antique specimens of this taxon at least 100 years 
old, as defined by section 10(h)(1) of the Act.
    (4) Unauthorized destruction or alteration of Miami blue butterfly 
habitat (including unauthorized grading, leveling, plowing, mowing, 
burning, trampling, herbicide spraying, or other destruction or 
modification of occupied or potentially occupied habitat or pesticide 
application in known occupied habitat) in ways that kills or injures 
eggs, larvae, or adult Miami blue butterflies by significantly 
impairing the subspecies' essential breeding, foraging, sheltering, or 
other essential life functions.
    (5) Use of pesticides/herbicides that are in violation of label 
restrictions resulting in take of Miami blue butterfly or beneficial 
ants associated with the subspecies in areas occupied by the butterfly.
    (6) Unauthorized release of biological control agents that attack 
any life stage of this taxon or beneficial ants associated with the 
Miami blue.
    (7) Removal or destruction of native food plants being utilized by 
Miami blue butterfly, including Caesalpinia spp., Cardiospermum spp., 
and Pithecellobium spp., within areas used by this taxon that results 
in harm to this butterfly.
    (8) Release of exotic species into occupied Miami blue butterfly 
habitat that may displace the Miami blue or its native host plants.
    We will review other activities not identified above on a case-by-
case basis to determine whether they may be likely to result in a 
violation of section 9 of the Act. We do not consider these lists to be 
exhaustive, and we provide them as information to the public.
    You should direct questions regarding whether specific activities 
may constitute a future violation of section 9 of the Act to the Field 
Supervisor of the Service's South Florida Ecological Services Field 
Office (see FOR FURTHER INFORMATION CONTACT). Requests for copies of 
regulations regarding listed species and inquiries about prohibitions 
and permits should be addressed to the U.S. Fish and Wildlife Service, 
Ecological Services Division, Endangered Species Permits, 1875 Century 
Boulevard, Atlanta, GA 30345 (Phone 404-679-7313; Fax 404-679-7081).

Similarity of Appearance

    Section 4(e) of the Act authorizes the treatment of a species, 
subspecies, or population segment as endangered or threatened if: ``(a) 
such species so closely resembles in appearance, at the point in 
question, a species which has been listed pursuant to such section that 
enforcement personnel would have substantial difficulty in attempting 
to differentiate between the listed and unlisted species; (b) the 
effect of this substantial difficulty is an additional threat to an 
endangered or threatened species; and (c) such treatment of an unlisted 
species will substantially facilitate the enforcement and further the 
policy of this Act.'' Listing a species as endangered or threatened 
under the similarity of appearance provisions of the Act extends the 
take prohibitions of section 9 of the Act to cover the species. A 
designation of endangered or threatened due to similarity of appearance 
under section 4(e) of the Act, however, does not extend other 
protections of the Act, such as consultation requirements for Federal 
agencies under section 7 and the recovery planning provisions under 
section 4(f), that apply to species that are listed as endangered or 
threatened under section 4(a). All applicable prohibitions and 
exceptions for species listed under section 4(e) of the Act due to 
similarity of appearance to a threatened or endangered species will be 
set forth in a special rule under section 4(d) of the Act.
    There are only slight morphological differences between the Miami 
blue and the cassius blue, ceraunus blue, and nickerbean blue, making 
it difficult to differentiate between the species, especially due to 
their small size (see Background above). Aside from technical experts, 
most people would have difficulty distinguishing these similar 
butterflies (as adults, eggs, or larvae), especially without field 
guides or when adults are in flight. This poses a problem for Federal 
and State law enforcement agents trying to stem illegal collection and 
trade in the Miami blue. It is quite possible that collectors 
authorized to collect similar species may inadvertently (or 
purposefully) collect the Miami blue butterfly thinking it was the 
cassius blue, ceraunus blue, or nickerbean blue, which also occur in 
the same geographical area and habitat type. The listing of these 
similar blue butterflies as threatened due to similarity of appearance 
reduces the likelihood that amateur butterfly enthusiasts and private 
and commercial collectors will purposefully or accidentally 
misrepresent the Miami blue as one of these other species.
    The listing will also facilitate Federal and State law enforcement 
agents' efforts to curtail illegal possession, collection, and trade in 
the Miami blue. At this time, the three similar butterflies are not 
protected by the State of Florida. Extending the prohibitions of 
collection to the three similar butterflies through this listing of 
these species due to similarity of appearance under section 4(e) of the 
Act and providing applicable prohibitions and exceptions under section 
4(d) of the Act will provide

[[Page 20985]]

greater protection to the Miami blue. For these reasons, we are listing 
the cassius blue butterfly (Leptotes cassius theonus), ceraunus blue 
butterfly (Hemiargus ceraunus antibubastus), and nickerbean blue 
butterfly (Cyclargus ammon) as threatened due to similarity of 
appearance to the Miami blue, in portions of their ranges, pursuant to 
section 4(e) of the Act. Therefore, the cassius blue, ceraunus blue, 
and nickerbean blue butterflies are listed as threatened species under 
the Act due to similarity of appearance only within the historical 
range of the Miami blue butterfly in Florida. This includes the coastal 
counties south of Interstate 4 (I-4) and extending to the boundaries of 
the State at the endpoints of I-4 at Tampa and Daytona Beach.
    We are limiting the listing of these similar butterflies to only a 
portion of their ranges because we find this is sufficient to protect 
the Miami blue (from collection) while being responsive to comments 
received (see Comments Relating to Similarity of Appearance 
Butterflies, especially Comment 17 and Response above).

Special Rule Under Section 4(d) of the Act

    Whenever a species is listed as a threatened species under the Act, 
the Secretary may specify regulations that he deems necessary and 
advisable to provide for the conservation of that species under the 
authorization of section 4(d) of the Act. These rules, commonly 
referred to as ``special rules,'' are found in part 17 of title 50 of 
the Code of Federal Regulations (CFR) in Sec. Sec.  17.40-17.48. This 
special rule for Sec.  17.47 prohibits take of any cassius blue 
butterfly (Leptotes cassius theonus), ceraunus blue butterfly 
(Hemiargus ceraunus antibubastus), or nickerbean blue butterfly 
(Cyclargus ammon) or their immature stages only throughout coastal 
south and central Florida in order to protect the Miami blue butterfly 
from collection, possession, and trade. In this context, any activity 
where cassius blue, ceraunus blue, or nickerbean blue butterflies or 
their immature stages are attempted to be, or are intended to be, 
collected, in counties that overlap with the Miami blue's historical 
range in Florida, are prohibited. Collection of the similar butterflies 
is prohibited south of I-4 and extending to the boundaries of the State 
of Florida at the endpoints of I-4 at Tampa and Daytona Beach. 
Specifically, such activities are prohibited in the following counties: 
Brevard, Broward, Charlotte, Collier, De Soto, Hillsborough, Indian 
River, Lee, Manatee, Pinellas, Sarasota, St. Lucie, Martin, Miami-Dade, 
Monroe, Palm Beach, and Volusia.
    Capture of cassius blue, ceraunus blue, or nickerbean blue 
butterflies, or their immature stages, is not prohibited if it is 
accidental or incidental to otherwise legal collection activities, such 
as research, provided the animal is released immediately upon discovery 
at the point of capture. Scientific activities involving collection or 
propagation of these similarity of appearance butterflies are not 
prohibited, provided there is prior written authorization from the 
Service. All otherwise legal activities involving cassius blue, 
ceraunus blue, or nickerbean blue butterflies that are conducted in 
accordance with applicable State, Federal, Tribal, and local laws and 
regulations are not considered to be take under this regulation. For 
further explanation see ``Effects of the Rule'' immediately below.

Effects of the Rule

    Listing the cassius blue, ceraunus blue, and nickerbean blue 
butterflies as threatened under the ``similarity of appearance'' 
provisions of the Act, and the promulgation of a special rule under 
section 4(d) of the Act, extend take prohibitions to these species and 
their immature stages in portions of their ranges. Capture of these 
species, including their immature stages, is not prohibited if it is 
accidental or incidental to otherwise legal collection activities, such 
as research, provided the animal is released immediately upon 
discovery, at the point of capture. However, this final rule 
establishes prohibitions on the collection of these species throughout 
coastal south and central Florida within the historical range of the 
Miami blue butterfly.
    All otherwise legal activities that may involve incidental take 
(take that results from, but is not the purpose of, carrying out an 
otherwise lawful activity) of these similar butterflies, and which are 
conducted in accordance with applicable State, Federal, Tribal, and 
local laws and regulations, will not be considered take under this 
regulation. For example, this special 4(d) rule exempts legal 
application of pesticides, yard care, vehicle use, vegetation 
management, exotic plant removal, burning, and any other legally 
undertaken actions that result in the accidental take of cassius blue, 
ceraunus blue, or nickerbean blue butterflies. These actions will not 
be considered as violations of section 9 of the Act. We find that 
listing the cassius blue, ceraunus blue, and nickerbean blue 
butterflies under the similarity of appearance provision of the Act, 
coupled with this special 4(d) rule, will help minimize enforcement 
problems and enhance conservation of the Miami blue.
    The provision to allow incidental take of these three similar 
butterflies will not pose a threat to the Miami blue because: (1) 
Activities such as yard care and vegetation control in developed or 
commercial areas that are likely to result in take of the cassius blue, 
ceraunus blue, and nickerbean blue are not likely to affect the Miami 
blue (which occur only on conservation lands), and (2) the primary 
threat that activities concerning the cassius blue, ceraunus blue, and 
nickerbean blue butterflies pose to the Miami blue comes from 
collection.

Administrative Procedure Act

    As explained previously in Previous Federal Actions above, we 
believe that it is necessary to establish immediate protections under 
the Act for these butterfly species. The August 10, 2011, emergency 
rule (76 FR 49542) that implemented protections for 240 days expires 
April 6, 2012. Therefore, under the exemption provided in the 
Administrative Procedure Act (5 U.S.C. 553(d)(3)), we have determined 
that ``good cause'' exists to make these regulations effective as 
stated above (see DATES).

Required Determinations

Clarity of Rule

    We are required by Executive Orders 12866 and 12988 and by the 
Presidential Memorandum of June 1, 1998, to write all rules in plain 
language. This means that each rule we publish must: (a) Be logically 
organized; (b) Use the active voice to address readers directly; (c) 
Use clear language rather than jargon; (d) Be divided into short 
sections and sentences; and (e) Use lists and tables wherever possible.
    If you feel that we have not met these requirements, send us 
comments by one of the methods listed in the ADDRESSES section. To 
better help us revise the rule, your comments should be as specific as 
possible. For example, you should tell us page numbers and the names of 
the sections or paragraphs that are unclearly written, which sections 
or sentences are too long, the sections where you feel lists or tables 
would be useful, etc.

Paperwork Reduction Act (44 U.S.C. 3501, et seq.)

    This final rule does not contain any new collections of information 
that require approval by the Office of Management and Budget (OMB) 
under the Paperwork Reduction Act. This rule will not impose new 
recordkeeping or

[[Page 20986]]

reporting requirements on State or local governments, individuals, 
businesses, or organizations. We may not conduct or sponsor, and you 
are not required to respond to, a collection of information unless it 
displays a currently valid OMB control number.

National Environmental Policy Act (42 U.S.C. 4321 et seq.)

    We have determined that we do not need to prepare an environmental 
assessment, as defined under the authority of the National 
Environmental Policy Act of 1969, in connection with regulations 
adopted under section 4(a) of the Act. We published a notice outlining 
our reasons for this determination in the Federal Register on October 
25, 1983 (48 FR 49244).

References Cited

    A complete list of all references cited in this final rule is 
available on the Internet at http://www.regulations.gov or upon request 
from the Field Supervisor, South Florida Ecological Services Office 
(see FOR FURTHER INFORMATION CONTACT).

Authors

    The primary authors of this rule are staff members of the South 
Florida Ecological Services Office (see FOR FURTHER INFORMATION 
CONTACT).

List of Subjects in 50 CFR Part 17

    Endangered and threatened species, Exports, Imports, Reporting and 
recordkeeping requirements, Transportation.

Regulation Promulgation

    Accordingly, we amend part 17, subchapter B of chapter I, title 50 
of the Code of Federal Regulations, as follows:

PART 17--[AMENDED]

0
1. The authority citation for part 17 continues to read as follows:

    Authority:  16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C. 
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.

0
2. Amend Sec.  17.11(h) by adding new entries for the following, in 
alphabetical order under Insects, to the List of Endangered and 
Threatened Wildlife:


Sec.  17.11  Endangered and threatened wildlife.

* * * * *
    (h) * * *

--------------------------------------------------------------------------------------------------------------------------------------------------------
                           Species                                                        Vertebrate
--------------------------------------------------------------                            population
                                                                    Historic range           where              Status          When listed    Critical
             Common name                  Scientific name                                endangered or                                         habitat
                                                                                          threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
 
                                                                      * * * * * * *
               Insects
 
                                                                      * * * * * * *
Butterfly, cassius blue.............  Leptotes cassius         U.S.A. (FL), Bahamas,                NA  T (S/A) (coastal south          801           NA
                                       theonus.                 Greater Antilles,                        and central FL).
                                                                Cayman Islands.
Butterfly, ceraunus blue............  Hemiargus ceraunus       U.S.A. (FL), Bahamas...              NA  T (S/A) (coastal south          801           NA
                                       antibubastus.                                                     and central FL).
 
                                                                      * * * * * * *
Butterfly, Miami blue...............  Cyclargus thomasi        U.S.A. (FL), Bahamas...              NA  E.....................          801           NA
                                       bethunebakeri.
 
                                                                      * * * * * * *
Butterfly, nickerbean blue..........  Cyclargus ammon........  U.S.A. (FL), Bahamas,                NA  T (S/A) (coastal south          801           NA
                                                                Cuba.                                    and central FL).
 
                                                                      * * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------


0
3. In subpart D, add Sec.  17.47 to read as follows:


Sec.  17.47  Special rules--insects.

    (a) Cassius blue butterfly (Leptotes cassius theonus), Ceraunus 
blue butterfly (Hemiargus ceraunus antibubastus), and Nickerbean blue 
butterfly (Cyclargus ammon).
    (1) The provisions of Sec.  17.31(c) apply to these species 
(cassius blue butterfly, ceraunus blue butterfly, nickerbean blue 
butterfly), regardless of whether in the wild or in captivity, and also 
apply to the progeny of any such butterfly.
    (2) Any violation of State law will also be a violation of the Act.
    (3) Incidental take, that is, take that results from, but is not 
the purpose of, carrying out an otherwise lawful activity, will not 
apply to the cassius blue butterfly, ceraunus blue butterfly, and 
nickerbean blue butterfly.
    (4) Collection of the cassius blue butterfly, ceraunus blue 
butterfly, and nickerbean blue butterfly is prohibited in coastal 
counties south of Interstate 4 and extending to the boundaries of the 
State of Florida at the endpoints of Interstate 4 at Tampa and Daytona 
Beach. Specifically, such activities are prohibited in the following 
counties: Brevard, Broward, Charlotte, Collier, De Soto, Hillsborough, 
Indian River, Lee, Manatee, Pinellas, Sarasota, St. Lucie, Martin, 
Miami-Dade, Monroe, Palm Beach, and Volusia.
    (b) [Reserved].

    Dated: March 27, 2012.
Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-8088 Filed 4-5-12; 8:45 am]
BILLING CODE 4310-55-P