[Federal Register Volume 79, Number 155 (Tuesday, August 12, 2014)]
[Rules and Regulations]
[Pages 47222-47244]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2014-18614]
[[Page 47221]]
Vol. 79
Tuesday,
No. 155
August 12, 2014
Part III
Department of the Interior
-----------------------------------------------------------------------
Fish and Wildlife Service
-----------------------------------------------------------------------
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; Endangered Status for
the Florida Leafwing and Bartram's Scrub-Hairstreak Butterflies; Final
Rule
Federal Register / Vol. 79 , No. 155 / Tuesday, August 12, 2014 /
Rules and Regulations
[[Page 47222]]
-----------------------------------------------------------------------
DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R4-ES-2013-0084; 4500030113]
RIN 1018-AZ08
Endangered and Threatened Wildlife and Plants; Endangered Status
for the Florida Leafwing and Bartram's Scrub-Hairstreak Butterflies
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: We, the U.S. Fish and Wildlife Service, determine endangered
species status under the Endangered Species Act of 1973, as amended,
for the Florida leafwing (Anaea troglodyta floridalis) and Bartram's
scrub-hairstreak (Strymon acis bartrami), two butterflies endemic to
South Florida. This final rule implements the protections provided by
the Act for these species. This regulation will result in the addition
of these species to the List of Endangered and Threatened Wildlife.
DATES: This rule becomes effective September 11, 2014.
ADDRESSES: This final rule is available on the Internet at http://www.regulations.gov and at http://www.fws.gov/verobeach/. Comments and
materials we received, as well as supporting documentation used in
preparation of this rule, are available for public inspection at http://www.regulations.gov. All of the comments, materials, and documentation
that we considered in this rulemaking are available by appointment,
during normal business hours, at U.S. Fish and Wildlife Service, South
Florida Ecological Services Office, 1339 20th Street, Vero Beach, FL
32960; telephone 772-562-3909; facsimile 772-562-4288.
FOR FURTHER INFORMATION CONTACT: Craig Aubrey, Field Supervisor, U.S.
Fish and Wildlife Service, South Florida Ecological Services Office,
1339 20th Street, Vero Beach, FL 32960, by telephone 772-562-3909, or
by facsimile 772-562-4288. Persons who use a telecommunications device
for the deaf (TDD) may call the Federal Information Relay Service
(FIRS) at 800-877-8339.
SUPPLEMENTARY INFORMATION:
Executive Summary
Why we need to publish a rule. Under the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.) (Act), a species may warrant
protection through listing if we find that it is an endangered or
threatened species throughout all or a significant portion of its
range. Listing a species as endangered or threatened can only be
completed by issuing a rule. Elsewhere in today's Federal Register, we
designate critical habitat for the Florida leafwing butterfly and the
Bartram's scrub-hairstreak butterfly under the Act.
This rule will finalize the listing of the Florida leafwing
butterfly and the Bartram's scrub-hairstreak butterfly as endangered
species.
The basis for our action. Under the Act, the U.S. Fish and Wildlife
Service (Service) can determine that a species is an endangered or
threatened species based on any of 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. We have determined the Florida
leafwing and Bartram's scrub-hairstreak butterflies meet the definition
of an endangered species based on all five factors.
Peer review and public comment. We sought comments from eight
independent experts to ensure that our action is based on
scientifically sound data, assumptions, and analyses. We invited these
peer reviewers to comment on our listing proposal. We also considered
all other comments and information received during the comment period.
Previous Federal Actions
Please refer to the proposed listing rule for the Florida leafwing
and Bartram's scrub-hairstreak butterflies (78 FR 49878; August 15,
2013) for a detailed description of previous Federal actions concerning
these species.
Summary of Comments and Recommendations
In the proposed rule published on August 15, 2013 (78 FR 49878), we
requested that all interested parties submit written comments on the
proposal by October 15, 2013. 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 and Key West Citizen.
We published proposed rules concurrently for both the proposed
listing of the Florida leafwing and Bartram's scrub-hairstreak, as well
as the proposed designation of critical habitat for these two
butterflies. Although the proposed rules were published in separate
Federal Register notices, we received combined comments from the public
on both actions. However, in this final rule we address only those
comments that apply to the listing of the Florida leafwing and
Bartram's scrub-hairstreak. Comments on the proposed critical habitat
are addressed in the final critical habitat rule. All substantive
information provided during the comment period has either been
incorporated directly into this final determination or addressed below.
Peer Reviewer Comments
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinions from eight knowledgeable
individuals with scientific expertise that included familiarity with at
least one of the two subspecies and its habitat, biological needs, and
threats; the geographical region of South Florida in which these
subspecies occur; and conservation biology principles. We received
responses from seven of the peer reviewers we contacted.
We reviewed all comments we received from the peer reviewers for
substantive issues and new information regarding the proposed listing
of the Florida leafwing and Bartram's scrub-hairstreak butterflies. The
peer reviewers generally concurred with our methods and conclusions,
and provided additional information, clarifications, and suggestions to
improve the final listing rule. Peer reviewer comments are addressed in
the following summary and incorporated into this final rule as
appropriate.
(1) Comment: One peer reviewer, as well as two public commenters,
indicated that developing appropriate monitoring schemes to understand
population biology, dynamics, dispersal abilities and various
environmental variables will be critical to advancing recovery goals.
Our Response: We agree that more rigorous information regarding
population monitoring, ecological studies, and other ongoing or future
research and recovery efforts for the Florida leafwing and Bartram's
scrub-hairstreak are needed, and we have updated the Population
Estimates and Status sections, below.
(2) Comment: Two peer reviewers indicated the importance of
disturbance
[[Page 47223]]
regimes, such as fire, to achieving conservation goals for these
subspecies, and that active adaptive management should be implemented.
Our Response: We incorporated new information regarding fire
management plans, as well as ongoing and future studies designed to
measure the influence of prescribed burns and other management actions
(such as mechanical clearing), into the Factor A discussion, below.
(3) Comment: One peer reviewer mentioned the importance of smaller
parcels for conservation. The reviewer also asked for clarification
regarding the amount of remaining pine rockland habitat.
Our Response: We agree that even small parcels of extant pine
rocklands have important conservation value to imperiled butterflies.
One of the analyses we cite in this rule (Institute for Regional
Conservation 2006) pertained only to pineland croton occurrence on
parcels greater than a single hectare. However, all extant pine
rockland, with or without hostplant populations, were reviewed, both
for the proposed listing rule and the proposed rule to designate
critical habitat. The reference to 1,780 hectares (ha) (4,400 acres
(ac)) of remaining pine rockland habitat refers only to 375 parcels of
extant pine rockland within Miami-Dade County, outside of Everglades
National Park (ENP). We have revised the information on extant pine
rockland habitat and known hostplant distribution under the Habitat
section, below.
(4) Comment: One peer reviewer provided a link to research findings
on the potential impact of sea-level rise on south Florida butterflies.
Our Response: We incorporated this new information into the Factor
A discussion, below.
(5) Comment: One peer reviewer indicated that, based on the threat
of habitat loss from climate change, development, and other factors, it
may be important to consider appropriate habitat at the fringes of the
subspecies' historical ranges (Martin and Palm Beach Counties) in
conservation planning.
Our Response: Although the Florida leafwing and Bartram's
hairstreak are only known to have occurred sporadically outside of
Monroe and Miami-Dade Counties, Florida, future recovery actions may
include efforts within the more northern parts of their historical
ranges that retain hostplant populations. We incorporated information
regarding this potential recovery option into the Factor A discussion,
below.
(6) Comment: One peer reviewer indicated that pineland croton
(Croton linearis) has sometimes been referred to by the common name of
woolly croton. In addition, C. linearis and C. cascarilla are
synonymous in the literature.
Our Response: We incorporated this new information into the General
Biology section of the Florida leafwing.
(7) Comment: One peer reviewer indicated that the high level of
parasitism on immature Florida leafwing is not something that can be
controlled. As a result, recovery efforts should focus on the adult
stages.
Our Response: We agree and have incorporated this new information
into the Factor C discussion, below.
(8) Comment: One peer reviewer provided a correction indicating
that the Florida leafwing had not been included throughout the
Determination section of the proposed rule.
Our Response: We have incorporated the Florida leafwing throughout
the Determination section of the final rule, below.
(9) Comment: One peer reviewer indicated that existing evidence
supports the recognition of floridalis as a subspecies of Anaea
troglodyta and referenced several articles in the literature.
Our Response: We appreciate the information provided and have
incorporated it into the Taxonomy section for the Florida leafwing.
(10) Comment: One peer reviewer provided additional references in
the literature pertaining to life histories of the Florida leafwing and
Bartram's scrub-hairstreak. This reviewer also provided additional
references pertaining to the historical ranges of the butterflies.
Our Response: We appreciate the information provided and have
incorporated it into the Life History and Historical Ranges sections
for the Florida leafwing and Bartram's scrub-hairstreak.
(11) Comment: One peer reviewer indicated that the rarity of the
Florida leafwing and Bartram's scrub-hairstreak and difficulty in
collecting the leafwing, in particular, makes it unlikely that
collecting could impact the population.
Our Response: We appreciate the information; however, based on the
small localized nature of extant Florida leafwing and Bartram's scrub-
hairstreak populations, any removal of individuals at this time may
have an adverse impact to those populations. Based on information on
collecting pressures, small population sizes, and limited law
enforcement targeting butterfly collection, outlined in the proposed
rule and in our decision record, we believe there is sound scientific
information to conclude that collection poses a threat to these
butterflies.
(12) Comment: One peer reviewer suggests that many specimens of the
Florida leafwing and Bartram's scrub-hairstreak offered for sale online
may come from older collections, as opposed to poaching activities on
conservation lands.
Our Response: We appreciate the information provided and have
incorporated it into the Factor C discussion, below.
(13) Comment: Two peer reviewers support the proposed listing of
the Florida leafwing and Bartram's scrub-hairstreak as endangered, but
are skeptical as to what would be done to recover them. These reviewers
indicate recovery efforts have not been successful for the endangered
Schaus swallowtail or Miami blue butterflies and wonder what would be
done differently for the proposed butterflies, if listed.
Our Response: In accordance with section 4(f)(1) of the Act, we are
required to develop and implement a recovery plan for any species
listed as endangered or threatened under the Act unless ``such a plan
will not promote the conservation of the species.'' We believe a
recovery plan will promote the conservation of these species and would
address many of the factors outlined in the Summary of Factors
Affecting the Species, below.
(14) Comment: One peer reviewer suggested the phrase ``Collection,
which is prohibited on conservation lands, could occur (e.g., ENP,
National Key Deer Refuge [NKDR], State or County owned lands) without
being detected, because these areas are all not actively patrolled . .
.'' could attract poachers to these areas.
Our Response: We appreciate the information provided, but feel the
language, as written, emphasizes the threat of collection and where
additional conservation actions may be warranted.
(15) Comment: One peer reviewer indicates that, while he agrees
that mark-release-recapture techniques may be harmful to small
lycaenids, it is important to emphasize the potential downsides of not
using such a technique, namely possible recounting, etc.
Our Response: We appreciate the information provided and have
incorporated it into the Factor B discussion, below.
(16) Comment: One peer reviewer indicates that research on
symbiosis between lycaenids and ants for the Miami blue should be
included for the
[[Page 47224]]
immature stages of the Bartram's scrub-hairstreak.
Our Response: Although a symbiotic relationship between Bartram's
scrub-hairstreak larvae and ants has not been documented, we appreciate
the information provided and have incorporated it into the Factor C
discussion for the hairstreak, below.
(17) Comment: One peer reviewer indicates that adult Bartram's
scrub-hairstreak have been observed within Zoo Miami in recent years
and that it should be mentioned within the summary of known extant
population.
Our Response: We appreciate the information provided and have
incorporated it into the Current Range section of the Bartram's scrub-
hairstreak.
(18) Comment: One peer reviewer indicated that existing data do not
support the necessity of indicating a specified return interval for
disturbance (i.e., 3 to 5 years for fire) for Long Pine Key. The
commenter indicated that the butterflies have been observed at varying
densities within pine rocklands in Long Pine Key that have burned at
intervals of up to 10 years.
Our Response: We agree that, while the literature (Florida Natural
Areas Inventory (FNAI) 2010a, p. 3) indicates a fire-return interval of
approximately 3 to 7 years is appropriate for maintaining the pine
rockland ecosystem, there is considerable variability in population
numbers of the Florida leafwing and Bartram's scrub-hairstreak from
year to year. Observations of the Florida leafwing and Bartram's scrub-
hairstreak within portions of Long Pine Key that have experienced fire
or other disturbance regimes at intervals of up to 10 years (Salvato
and Salvato 2010a, p. 91; 2010b, p. 154; Sadle 2013c, pers. comm.)
suggest further studies are required on the influence of these factors
on butterfly ecologies. We appreciate the information provided and have
incorporated it into the Factor A discussion, below.
(19) Comment: One peer reviewer, as well as one public comment,
indicated that it may not be accurate to call Bartram's scrub-
hairstreak a sedentary butterfly.
Our Response: We agree that, although the Bartram's scrub-
hairstreak is often described as sedentary, the need to evade natural
disturbance (fires, storms) and subsequently recolonize suggests that
adult hairstreaks, perhaps as a function of age, sex, or density, are
adapted for effective dispersal throughout the pine rockland and
associated ecosystems. We appreciate the information provided and have
incorporated it into the Life History discussion for the hairstreak,
below.
(20) Comment: One peer reviewer indicated that an additional
habitat, hydric pine flatwoods, is often used during dispersal by the
Florida leafwing and Bartram's scrub-hairstreak, when it is adjacent or
interspersed within pine rocklands.
Our Response: We appreciate the information provided and have
included a description of hydric pine flatwoods in the Habitat section,
below.
Comments From States
Section 4(b)(5)(A)(ii) of the Act requires the Secretary, not less
than 90 days before publication of a final listing rule, to give actual
notice of the rule to the State agency in each State in which the
species is believed to occur, and invite the comment of such agency on
the proposal. The two subspecies only occur in Florida, and we received
comment letters from two entities from the State of Florida regarding
the listing proposal. The Florida Fish and Wildlife Conservation
Commission (FWC) found the document to be comprehensive, with
conclusions that are well-documented and justified, but otherwise did
not provide substantive comments requiring a response. The Florida
Department of Agriculture and Consumer Services (FDACS) neither
supported nor opposed the proposed listing, but indicated their intent
to work with the Service and other stakeholders in protecting imperiled
species, as well as determining ways to mitigate potential risks of
pesticide use and mosquito control toward imperiled species in Florida.
(21) Comment: FDACS indicated that, given the current mosquito
control district cooperation, any future considerations concerning
research addressing potential for and magnitude of impact of mosquito
control practices on imperiled butterflies, including the Florida
leafwing and Bartram's hairstreak, should continue to be discussed in
this forum where mosquito control districts can actively participate.
Our Response: We agree and appreciate the mosquito control
districts' cooperation and willingness to help support and direct
research to minimize potential pesticide impacts on imperiled
butterflies.
Public Comments
During the comment period for the proposed listing rule, we
received a total of 18 comment letters regarding the proposed listing:
2 from Florida State agencies (addressed above) and 16 from local
governments, nongovernmental organizations, and private citizens. Of
the 16 non-State letters, 12 indicated support of the proposed listing,
but otherwise did not provide specific comments on the rule. Four of
the comment letters provided substantive comments regarding two general
issues. We did not receive any requests for a public hearing.
Issue 1: Mosquito Control
(22) Comment: One commenter questioned the inclusion of mosquito
control activities as a factor affecting the species and suggested that
habitat loss is the primary factor impacting the butterflies. The
commenter also stated that ``it is reasonable and prudent to coordinate
control measures to minimize risk in the remaining limited habitat
areas'' and that ``protecting and preserving the species habitat
through acquisition seems to be the most reasonable means of preserving
the species.''
Our Response: We agree that habitat loss has been a major factor
leading to the current status of the Florida leafwing and Bartram's
scrub-hairstreak. However, as discussed in Factor E--Other Natural or
Manmade Factors Affecting Its Continued Existence, below, we believe
mosquito control activities are also a factor affecting these
butterflies. We agree that protecting and preserving remaining habitat
will be critical in the conservation and recovery of the butterflies
and that mosquito control efforts should be coordinated between the
Service and mosquito control districts in areas where suitable or
occupied habitats exist.
(23) Comment: Three counties (Lee, Manatee, and Lake) and another
commenter recommended that mosquito control activities not be included
as a factor affecting the species. The commenters state that this
inclusion would lead to restrictions on mosquito control operations
that would be detrimental to public health and the economy of south
Florida.
Our Response: The use of broad spectrum insecticides in and around
Florida leafwing and Bartram's scrub-hairstreak habitat during mosquito
control operations is a factor that must be considered when assessing
threats to the species. The Act requires us to base our determination
for listing a species ``solely on the basis of the best scientific and
commercial data available'' (section 4(b)(1)(A)). The Service has
worked proactively in the past with mosquito control districts within
habitat of the endangered Schaus' swallowtail (Papilio aristodemus
ponceanus) (Hennessey et al. 1992, p. 715; Salvato 2001, p. 8) in order
to coordinate mosquito control activities in such a way that public
[[Page 47225]]
health is adequately protected while still promoting conservation and
recovery of the species. As a result, we believe similar cooperation
between the Service and mosquito control districts will occur in
suitable or occupied habitat of the Florida leafwing and Bartram's
scrub-hairstreak. Under public health emergency conditions, the Service
would not impose restrictions that would jeopardize the safety or well-
being of the public.
(24) Comment: Lee County contends that Salvato's (2001) suggestion
that butterflies roosting in the canopy would be vulnerable to aerial
mosquito control spray is incorrect, and that roosting under leaves
would actually provide protection to the butterflies. Lee and Manatee
Counties also state that using caged, nontarget insects to examine
pesticide effects in the field following application events is not
realistic and has a high level of bias in favor of an adverse effect.
Specifically, Lee County mentions the work of Zhong et al. (2010) where
larval and adult butterflies were exposed without the ability to seek
refuge after dark, while Manatee County mentions the work of Bargar
(2011) where caged species were placed in open field areas.
Our Response: The Service agrees that refugia, including
vegetation, may help to ameliorate pesticide effects on some field-
exposed organisms. The extent to which such refugia may protect against
pesticide exposure is unknown. However, with no data to support the
assertion that vegetative refugia prevents impacts to butterflies from
mosquito control application, the Service must rely on the best
available data, which suggests that impacts to butterflies are a
possibility.
(25) Comment: Lee County states that the risk assessment presented
in Hoang et al. (2011) inappropriately uses the residue data from
Pierce (2009). The commenter contends that pesticide residues
quantified on surfaces in the environment would not be equivalent to
residues on cryptic insects and that Hoang et al. (2011) assigns risk
without considering actual insect contact with pesticides in the field.
Our Response: The Service considers the risk analysis presented in
Hoang et al. (2011, pp. 997-1005) to be a screening-level evaluation
that examined worst-case scenarios, evidenced by the fact that the
highest quantified deposition values from Pierce (2009, pp. 1-20) were
used to determine risk. Actual insect exposures may vary from the
deposition observed on leaves and filter pads, but no relevant field-
derived insect pesticide body load analysis has been conducted. With no
supporting data to the contrary, the Service cannot assume insect
exposure values are below a level of concern.
(26) Comment: Lee County states that the Environmental Protection
Agency (EPA) labels pesticides for uses that do not pose unacceptable
risk to individuals and the environment and that ``the EPA has
successfully assessed the risk for mosquito control practices since no
connection between pesticide residues and insect mortality outside of
target zone is cited'' by the Service. Manatee County also states that
the EPA's registration of aerial adulticides implies that the EPA has
determined that this practice does not harm butterfly populations.
Our Response: The Service acknowledges that more information is
needed to better quantify the drift, and subsequent effects, of
mosquito control chemicals outside of target zones. Registration of a
pesticide by the EPA does not imply that there are no nontarget species
potentially at risk from label-approved uses. When registering
pesticides, the EPA does not conduct exhaustive testing on terrestrial
invertebrates. Honeybees are the only species subject to acute toxicity
testing. The results of such testing using naled and permethrin
determined that both pesticides are highly toxic to honeybees (EPA
2006a, p. 32; EPA 2006b, p. 81). Impacts of pesticides on butterfly
species are not currently considered during EPA's registration process.
(27) Comment: Manatee County states that the Service failed to
report that naled application rates were higher than expected due to
inaccurate GPS-guided flight patterns during the Zhong et al. (2010)
study, where a 73.9 percent survival rate of Miami blue butterfly
larvae was observed. The reviewer also states that Zhong had conducted
previous research on the same topic that showed no effects of aerial
naled application on Miami blue butterfly larvae.
Our Response: The data cited from Zhong et al. (2010, pp. 1967-
1970) came from a peer-reviewed journal article. No mention was made in
the journal article of any GPS-related impacts on the results of the
study; therefore, the Service has no such information to report. The
Service is also not aware of any additional work by Zhong that examined
naled impacts on the Miami blue butterfly, but would welcome any such
information.
(28) Comment: Manatee County suggests that mosquito control
spraying may be beneficial to butterfly populations. The County
references the work of Marc Minno, a lepidopterist who has conducted
butterfly population assessments in south Florida and has documented
significant butterfly populations in areas such as Miami and Key West
that receive mosquito control applications.
Our Response: The Service is open to considering all potential
aspects of the interaction between mosquito control practices and the
success of the Florida leafwing and Bartram's scrub-hairstreak. In-
depth analysis, beyond anecdotal observations of various species, would
be required to support the assertion that mosquito control practices
are beneficial to any species of interest.
(29) Comment: Lake County states that, if the two butterfly species
of interest are imperiled because of mosquito control practices, then
all other nontarget organisms with similar habitat needs and behaviors
would be in jeopardy. The reviewer also states that no impacts on
butterfly populations have occurred in Lake County despite more than 32
years of mosquito control activity.
Our Response: The Service believes that the individual life
histories of the butterfly species of interest, and their
susceptibilities to pesticide impacts, must be considered
independently, and that the status of other nontarget organisms cannot
be used as a surrogate during such consideration. The Service is also
not aware of any comprehensive assessment on the population status of
butterflies in Lake County, but would welcome such information.
(30) Comment: Lee County indicates that the Florida leafwing and
Bartram's scrub-hairstreak butterflies continue to exist in areas that
meet their environmental requirements, including those that have been
sprayed for 40 years.
Our Response: We agree that these butterflies have retained
populations in appropriate extant pine rockland habitat within Monroe
and Miami-Dade, including within areas actively treated with mosquito
control pesticides. However, we present evidence under the Factor E
discussion, below, that suggests pesticide application administered for
mosquito control may also have a collateral influence on the ecologies
of the Florida leafwing and Bartram's scrub-hairstreak. On the other
hand, at no point in the proposed or final listing rules is the role of
pesticide application considered as the sole contributor to the decline
in populations of these taxa, but merely one potential factor. The
purpose of the Summary of Factors Affecting the Species section
indicates all known or suspected factors, biological or anthropogenic,
and this does include pesticide applications.
[[Page 47226]]
Issue 2: Population Dynamics
(31) Comment: One commenter indicates that pineland croton may not
be the only larval hostplant used by the Bartram's scrub-hairstreak.
The commenter indicates other scrub-hairstreaks are generally known to
use a variety of larval hostplants, and that more field observation
might reveal additional hostplants for the Bartram's scrub-hairstreak.
Our Response: Extensive field studies have been conducted on the
Bartram's scrub-hairstreak over the past several decades; to date this
research has documented oviposition only on pineland croton. However,
we agree that ongoing ecological studies may indicate the hairstreak
occasionally uses other pine rockland plants for larval development. We
appreciate the information provided and have incorporated it into the
General Biology discussion for the hairstreak, below.
(32) Comment: Lee County indicates that the Florida leafwing shows
annual mortality of up to 70 percent based on increased predation from
exotic and native predators or parasites.
Our Response: There are a number of factors which influence the
populations of the Florida leafwing and Bartram's scrub-hairstreak.
However, the mortality mentioned by this reviewer is part of the
Florida leafwing's natural history. We have no evidence that natural
mortality, from predation or parasitism, of Florida leafwing
populations within the Long Pine Key portion of ENP is any different
now than it was historically.
(33) Comment: Lee County indicates that lack of burning on public
lands by the Service and its partners is correlated with the loss of
habitat for the Florida leafwing and Bartram's scrub-hairstreak. In
addition, these butterflies have shown increased population numbers in
response to an appropriate fire-return interval.
Our Response: As discussed in the previous comment, we agree that a
number of factors influence the populations of the Florida leafwing and
Bartram's scrub-hairstreak; this includes a lack of adequate fire
management within the pine rocklands on conservation lands.
(34) Comment: Lee County indicates that the Service desires to
expand the present range of the Florida leafwing and Bartram's scrub-
hairstreak to elsewhere in their historical ranges.
Our Response: We have proposed the listing of the Florida leafwing
and Bartram's scrub-hairstreak as endangered, as a first of many steps
designed to recover these butterflies. Implementing conservation
measures for populations of these butterflies within their extant or
recent historical distributions will be a primary goal of the recovery
plan, when drafted.
Summary of Changes From Proposed Rule
In the Background section, we made the following changes:
(1) We incorporated new information regarding population
monitoring, ecological studies, and other ongoing or future research
and recovery efforts for the Florida leafwing and Bartram's scrub-
hairstreak.
(2) We clarified our discussion on extant pine rockland habitat,
including smaller parcels, and known hostplant distribution.
(3) We indicated throughout the document that adult butterflies
will also make use of hydric pine flatwood vegetation when interspersed
within the pine rockland habitat.
(4) We included a full description of the hydric pine flatwoods
forest community.
(5) We indicated that additional studies are needed to understand
varying butterfly densities in response to pine rockland fire-return
intervals.
(6) We included additional information on the scientific and common
names of pineland croton.
(7) We included additional references that recognize floridalis as
a subspecies of Anaea troglodyte.
(8) We included additional references on the life histories of the
Florida leafwing and Bartram's scrub-hairstreak.
(9) We included additional references on the historical ranges of
the Florida leafwing and Bartram's scrub-hairstreak.
(10) We incorporated additional information on the current range of
the Bartram's scrub-hairstreak.
(11) We included additional information on larval hostplants used
by the Bartram's scrub-hairstreak.
(12) We included additional information regarding Bartram's scrub-
hairstreak dispersal abilities.
In the Summary of Factors Affecting the Species section, we made
the following changes:
(1) We incorporated new information regarding fire management
plans, as well as ongoing and future studies designed to measure the
influence of prescribed burns and other management actions (such as
mechanical clearing).
(2) We included new information on the potential impact of sea-
level rise on south Florida butterflies.
(3) We incorporated information regarding potential recovery
options based on the threat of habitat loss from climate change,
development, and other factors.
(4) We added that it may be important to consider appropriate
habitat at the fringes of the subspecies' historical ranges.
(5) We included the Florida leafwing in the Determination section.
(6) We included additional information regarding the potential
provenance of butterfly specimens offered for sale online.
(7) We corrected the title of the Imperiled Butterflies of Florida
Workgroup.
(8) We corrected the title of CERP to read as the Comprehensive
Everglades Restoration Plan.
(9) We incorporated information to emphasize the potential
downsides of not using mark-release-recapture techniques for butterfly
monitoring.
(10) We incorporated information on symbiosis between lycaenids and
ants under the discussion of Bartram's scrub-hairstreak predation.
Background
Please refer to the proposed listing rule for the Florida leafwing
and Bartram's scrub-hairstreak butterflies (78 FR 49878; August 15,
2013) for species information. The sections below represent summaries
of that information, and incorporate additions and edits based on peer
review and public comments.
Florida Leafwing
General Biology
The Florida leafwing butterfly is a medium-sized butterfly
approximately 76 to 78 millimeters (mm) (2.75 to 3.00 inches (in)) in
length with a forewing length of 34 to 38 mm (1.3 to 1.5 in) and an
appearance characteristic of its genus (Comstock 1961, p. 44; Pyle
1981, p. 651; Opler and Krizek 1984, p. 172; Minno and Emmel 1993, p.
153). The upper-wing (or open wing) surface color is red to red-brown.
The underside (closed wings) is gray to tan, with a tapered outline,
cryptically looking like a dead leaf or the bark of South Florida slash
pine trees (Pinus elliottii var. densa) when the butterfly is at rest.
The Florida leafwing exhibits sexual dimorphism (male and female are
different from each other), with females being slightly larger and with
darker coloring along the wing margins than the males.
The Florida leafwing has only one known hostplant, the pineland
croton (or woolly croton) (Croton linearis, formerly referred to as C.
cascarilla) (Euphorbiaceae).
Taxonomy
The Florida leafwing butterfly (Anaea troglodyta floridalis) was
first described
[[Page 47227]]
by Johnson and Comstock in 1941. Anaea troglodyta floridalis is a taxon
considered to be both endemic to south Florida and clearly derived from
Antillean stock (the islands of the West Indies except for the Bahamas,
separating the Caribbean Sea from the Atlantic Ocean) (Comstock 1961,
p. 45; Brown and Heineman 1972, p. 124; Minno and Emmel 1993, p. 153;
Smith et al. 1994, p. 67; Salvato 1999, p. 117; Hernandez 2004, p. 39;
Pelham 2008, p. 393). Some authors (Comstock 1961, p. 44; Miller and
Brown 1981, p. 164; Smith et al. 1994, p. 67; Hernandez 2004, p. 39)
placed the Florida leafwing as a distinct species, A. floridalis.
Others (Brown and Heineman 1972, p. 124; Minno and Emmel 1993, p. 153;
Salvato 1999, p. 117; Opler and Warren 2003, p. 40) considered the
Florida leafwing as a subspecies of Anaea troglodyta Fabricius. Smith
et al. (1994, p. 67) suggested that further comparison between immature
stages of the Florida leafwing and its Antillean relatives may aid in
determining whether or not the Florida leafwing is distinct at the
species or subspecies level. Calhoun (1997, p. 47), Opler and Warren
(2003, p. 40), Lamas (2004, p. 225) and Pelham (2008, p. 393)
considered Anaea troglodyta floridalis, not A. floridalis, as the
scientific name for the Florida leafwing.
The Integrated Taxonomic Information System (ITIS) (2013, p. 1)
uses the name Anaea troglodyta floridalis (F. Johnson and W. Comstock)
and indicates that this subspecies' taxonomic standing is valid. The
FNAI (2012, p. 19) uses the name A. t. floridalis.
Life History
Numerous authors have observed and documented the behavior and
natural history of the Florida leafwing (Matteson 1930, pp. 1-9;
Lenczewski 1980, p. 17; Pyle 1981, p. 651; Baggett 1982, pp. 78-79;
Opler and Krizek 1984, p. 172; Schwartz 1987, p. 22; Hennessey and
Habeck 1991, pp. 13-17; Smith et al. 1994, p. 67; Worth et al. 1996,
pp. 4-6; Salvato 1999, pp. 116-122; Salvato and Hennessey 2003, pp.
243-249; Salvato and Salvato 2008, pp. 323-329; 2010a, pp. 91-97).
Adults are rapid, wary fliers and have strong flight abilities and are
able to disperse over large areas. The Florida leafwing is multivoltine
(i.e., produces multiple generations per year), with an entire life
cycle of about 2 to 3 months (Hennessey and Habeck 1991, p. 17) and
maintains continuous broods throughout the year (Salvato 1999, p. 121).
The immature stages of this butterfly feed on pineland croton for
larval development. Eggs are spherical and light cream-yellow in color
(Worth et al. 1996, p. 64). Females lay eggs singly on both the upper
and lower surface of the host (croton plant) leaves, normally on
developing racemes (flowers) (Baggett 1982, p. 78; Hennessey and Habeck
1991, p. 16; Worth et al. 1996, p. 64; Salvato 1999, p. 120, Minno et
al. 2005, p. 115). Worth et al. (1996, p. 64) and Salvato (1999, p.
120) visually estimated that females may fly more than 30 meters (m)
(98 feet (ft)) in search of a suitable host plant.
Bartram's Scrub-Hairstreak
General Biology
The Bartram's scrub-hairstreak is a small butterfly approximately
25 mm (1 in) in length with a forewing length of 10.0 to 12.5 mm (0.4
to 0.5 in) and has an appearance characteristic of the genus (i.e.,
dark gray-colored on the upper (open) wings, light gray-colored under
(closed) wings, small size, body shape, distinctive white barring or
dots on underwings, and tailed hindwings) (Pyle 1981, p. 480; Opler and
Krizek 1984, pp. 107-108; Minno and Emmel 1993, p. 129). As with the
Florida leafwing, pineland croton is the only known hostplant for the
Bartram's scrub-hairstreak (Minno and Emmel 1993, p. 129; Smith et al.
1994, p. 118). However, other related scrub-hairstreak species, such as
the Martial scrub-hairstreak (Strymon martialis), while having
preference for bay cedar as a larval hostplant, have recently been
documented using nickerbean (Caesalpinia spp.) in the Florida Keys
(Daniels et al. 2005, pp. 174-175). Similarly, the mallow scrub-
hairstreak (Strymon istapa) has also been shown to use a variety of
host sources in southern Florida. While the Bartram's scrub-hairstreak
has been consistently documented to use pineland croton, further
natural history studies may indicate the subspecies' use of additional
pine rockland plants for larval development.
Taxonomy
The Bartram's scrub-hairstreak butterfly (Strymon acis bartrami)
was first described by Comstock and Huntington in 1943. Seven
subspecies of Strymon acis have been described (Smith et al. 1994, p.
118).
The ITIS (2013, p. 1) uses the name Strymon acis bartrami and
indicates that this subspecies' taxonomic standing is valid. FNAI
(2012, p. 21) uses the name S. a. bartrami.
Life History
The Bartram's scrub-hairstreak is rarely encountered more than 5 m
(16.4 ft) from its host plant-pine rockland interface (Schwartz 1987,
p. 16; Worth et al. 1996, p. 65; Salvato and Salvato 2008, p. 324).
Worth et al. (1996, p. 63) and Salvato and Hennessey (2004, p. 223)
indicate that the hairstreak may have limited dispersal abilities.
However, while the hairstreak is often described as sedentary, the need
to evade natural disturbance (fires, storms) and subsequently
recolonize suggests that adult hairstreaks--perhaps as a function of
age, sex, or density--are adapted for effective dispersal throughout
the pine rockland and associated ecosystems. Eggs are laid singly on
the flowering racemes of pineland croton (Worth et al., 1996, p. 62;
Salvato and Hennessey 2004, p. 225). First and second instars remain
well camouflaged amongst the white croton flowers, while the greenish
later stages occur more on the leaves.
The Bartram's scrub-hairstreak has been observed during every month
on Big Pine Key and in ENP; however, the exact number of broods appears
to vary sporadically from year to year (Salvato and Hennessey 2004, p.
226; Salvato and Salvato 2010b, p. 156).
Florida Leafwing and Bartram's Scrub-Hairstreak
Habitat
The Florida leafwing and Bartram's scrub-hairstreak occur only
within pine rocklands, specifically those that retain their mutual and
sole hostplant, pineland croton. Adult butterflies will also make use
of rockland hammock and hydric pine flatwood vegetation when
interspersed within the pine rockland habitat.
Detailed descriptions of pine rockland and rockland hammock
habitats are presented in the proposed listing rule for the Florida
leafwing and Bartram's scrub-hairstreak (78 FR 49882; August 15, 2013).
The hydric pine flatwoods community, interspersed within pine
rocklands, also supports Florida leafwing and Bartram's scrub-
hairstreak within the Long Pine Key region of ENP (Sadle 2013c, pers.
comm.). We include a full description of the hydric pine flatwoods
forest community below.
Hydric Pine Flatwoods--Hydric pine flatwoods (Service 1999, pp.
231-238; FNAI 2010b, pp. 1-2) are open pine forests with a sparse or
absent midstory and a dense groundcover of hydrophytic grasses, herbs,
and low shrubs. The pine canopy typically consists of South Florida
slash pine. Other pines may include longleaf pine (P. palustris),
[[Page 47228]]
pond pine (P. serotina), and loblolly pine (P. taeda). The subcanopy,
if present, consists of scattered sweetbay (Magnolia virginiana), swamp
bay (Persea palustris), loblolly bay (Gordonia lasianthus), pond
cypress (Taxodium ascendens), dahoon (Ilex cassine), titi (Cyrilla
racemiflora), and/or wax myrtle (Myrica cerifera). Shrubs include large
gallberry (Ilex coriacea), fetterbush (Lyonia lucida), titi, black titi
(Cliftonia monophylla), sweet pepperbush (Clethra alnifolia), red
chokeberry (Photinia pyrifolia), and azaleas (Rhododendron canescens,
R. viscosum). Saw palmetto (Serenoa repens) and gallberry (I. glabra),
species characteristic of mesic flatwoods sites, may be present. On
calcareous sites, cabbage palm (Sabal palmetto) is common both in the
subcanopy and shrub layers. Herbs include wiregrass (Aristida stricta
var. beyrichiana), blue maidencane (Amphicarpum muhlenbergianum), and/
or hydrophytic species such as toothache grass (Ctenium aromaticum),
cutover muhly (Muhlenbergia expansa), coastalplain yellow-eyed grass
(Xyris ambigua), Carolina redroot (Lachnanthes caroliana), beaksedges
(Rhynchospora chapmanii, R. latifolia, R. compressa), and pitcherplants
(Sarracenia spp.), among others. Hydric pine flatwoods occur in the
ecotones between the drier pine rocklands and rockland hammock habitats
(FNAI 2010b, pp. 1-2).
The relative density of shrubs and herbs varies greatly in hydric
pine flatwoods. Shrubs tend to dominate where fire has been absent for
a long period or where cool-season fires predominate; herbs are more
common in locations that are frequently burned. Soils and hydrology
also may influence relative density of shrubs and herbs. Soils of
shrubby hydric pine flatwoods are generally poorly to very poorly
drained sands and include such series as Rutledge/Osier; these soils
generally have a mucky texture in the uppermost horizon (FNAI 2010b, p.
2).
The general historical fire-return interval in pinelands across the
southeastern U.S. coastal plain is estimated to be every 1-3 years
(FNAI 2010b, p. 3). This interval is frequent enough to maintain grassy
hydric pine flatwoods and inhibit invasion by shrubs (Drewa et al.
2002). Hydric pine flatwoods that are naturally shrubbier and dominated
by slash pine may have had longer fire-return intervals, or perhaps a
few periods of longer intervals, on the order of 5-7 years (Landers
1991), or up to 5-10 years (Grelen 1980), in order to allow the pines
to establish and shrubs to proliferate.
Historical Ranges
The Florida leafwing and Bartram's scrub-hairstreak are endemic to
south Florida including the lower Florida Keys. The butterflies were
locally common within pine rockland habitat that once occurred within
Miami-Dade and Monroe Counties and were less common and sporadic within
croton-bearing pinelands in Collier, Martin (leafwing only), Palm
Beach, and Broward Counties (Skinner 1884, p. 180; Slosson 1895, p.
134; Comstock and Huntington 1943, p. 65; Kimball 1965, pp. 45-46;
Baggett 1982, p. 78; Minno and Emmel 1994, pp. 626-627; 1994b, pp. 649-
651; Smith et al. 1994, p. 67; Salvato 1999, p. 117; Salvato and
Hennessey 2003, p. 243; 2004, p. 223).
Current Ranges
Populations of Florida leafwing and Bartram's scrub-hairstreak have
become increasingly localized as pine rockland habitat has been lost or
altered through anthropogenic activity (Lenczewski 1980, p. 43; Baggett
1982, p. 78; Hennessey and Habeck 1991, p. 4; Schwarz et al. 1996, p.
59; Salvato and Hennessey 2003, p. 243; Salvato and Hennessey 2004, p.
223; Salvato and Salvato 2010a, p. 91; 2010b, p. 154).
Destruction of pine rocklands for economic development has reduced
this habitat in Miami-Dade County, including ENP, to about 11 percent
of its natural extent, from approximately 74,000 hectares (ha) (183,000
acres (ac)) to only 8,140 ha (20,100 ac) in 1996 (Kernan and Bradley
1996, p. 2). Outside of ENP, only about 1 percent of the Miami Rock
Ridge pinelands have escaped clearing, and much of what is left is in
small remnant fragments isolated from other natural areas (Herndon
1998, p. 1). Several of these fragments, particularly those adjacent to
ENP, such as Navy Wells and Richmond Pine Rocklands (a mixture of
publically and privately owned lands), maintain localized populations
of pineland croton as well as small or sporadic occurrences of
Bartram's scrub-hairstreak (Salvato 1999, p. 123; Salvato and Hennessey
2004, p. 223; Salvato and Salvato 2010b, p. 154; Salvato 2013, pers.
comm.; Maschinski et al. 2013, p. 14; Cook 2013, pers. comm.).
Breeding Florida leafwing populations have not been documented in
pine rockland fragments adjacent to ENP for the past 25 years. The
hairstreak retains breeding populations on Big Pine Key, on Long Pine
Key in ENP, and within a number of pine rockland fragments adjacent to
ENP.
The current distribution and abundance of pineland croton across
all extant pine rockland fragments within Miami-Dade County is not
known. However, a geographic information system analysis conducted by
the Service using data collected by The Institute for Regional
Conservation (IRC) in 2004, indicated that 77 pine rockland fragments
(totaling 516 ha (370 ac)) in Miami-Dade County, contained pineland
croton (IRC 2006, no page numbers). More recently, in 2012, the Service
funded Fairchild Tropical Botanic Gardens (FTBG) to conduct extensive
surveys of Miami-Dade pine rockland fragments to determine current
pineland croton abundance and distribution. Pineland croton populations
were encountered at 11 of the 13 locations surveyed, the largest
occurring at Navy Wells Pineland Preserve and the Richmond Pine
Rocklands, with each site retaining more than 21,000 individual plants
(Maschinski et al. 2013, pp. 11-12).
In the lower Florida Keys, Big Pine Key retains the largest
undisturbed tracts of pine rockland habitat (Zhang et al. 2010, p. 15;
Roberts 2012, pers. comm.). At present, within the Florida Keys,
pineland croton is known to occur only on Big Pine Key. Although the
Bartram's scrub-hairstreak is extant on Big Pine Key, the Florida
leafwing is believed to be extirpated from Big Pine Key since it has
not been seen on the island since 2006 (Minno and Minno 2009, pp. v, 9;
Salvato and Salvato 2010c, p. 139).
Population Estimates and Status
Florida Leafwing--Based on results of all historical (Baggett 1982,
p. 78; Schwartz 1987, p. 22; Hennessey and Habeck 1991, p. 17; Worth et
al. 1996, p. 62; Schwarz et al. 1996, p. 59) and recent surveys and
natural history studies (Salvato 1999, p. 1; 2001, p. 8; 2003, p. 53;
Salvato and Hennessey 2003, p. 243; Salvato and Salvato 2010a, p. 91),
the Florida leafwing is extant in ENP and, until recently, had occurred
on Big Pine Key and historically in pineland fragments in mainland
Miami-Dade County (Smith et al. 1994, p. 67; Salvato and Salvato 2010a,
p. 91; 2010c, p. 139). Results from all known historical surveys are
provided in Table 1. More recent studies are discussed below.
[[Page 47229]]
TABLE 1--Summary of historical Florida leafwing surveys
----------------------------------------------------------------------------------------------------------------
Size or density
Population Ownership\*\ Years numbers of adult Source
butterflies
----------------------------------------------------------------------------------------------------------------
National Key Deer Refuge--Big Federal--USFWS...... 1985-1986 34 observed or Schwartz (1987, p.
Pine Key. collected. 25).
National Key Deer Refuge--Watson Federal--USFWS...... 1988-1989 3.7 per ha (1.5 per Hennessey and Habeck
Hammock. acre). (1991, pp. 1-75).
Everglades National Park--Long Federal--NPS........ 1988-1989 3.7 per ha (1.5 per Hennessey and Habeck
Pine Key. acre). (1991, pp. 1-75).
Everglades National Park--Long Federal--NPS........ 1994-1995 22 observed......... Emmel et al. (1995,
Pine Key. p. 14).
National Key Deer Refuge--Big Federal--USFWS...... 1994-1995 19 observed......... Emmel et al. (1995,
Pine Key. p. 14).
National Key Deer Refuge--Watson Federal--USFWS...... 1997-1998 3.1 per ha (1.2 per Salvato (1999, p.
Hammock. acre). 52).
Everglades National Park--Long Federal--NPS........ 1997-1998 2.4 per ha (1 per Salvato (1999, p.
Pine Key. acre). 52).
----------------------------------------------------------------------------------------------------------------
\*\ USFWS--U.S. Fish and Wildlife Service; NPS--National Park Service.
Ongoing surveys conducted by Salvato (2014, pers. comm.) from 2009
to 2013 have recorded an average abundance of 2.7 adult Florida
leafwings per ha (1 per ac), in Long Pine Key in ENP. In addition,
surveys conducted by ENP staff from 2005 to present have encountered a
total of approximately 34 and 216 leafwing adults and larvae,
respectively, throughout Long Pine Key (Land 2012, pers. comm.; Sadle
2013b, pers. comm.).
No leafwings have been documented on Big Pine Key in the Florida
Keys since 2006 (Salvato and Salvato 2010c, p. 139). On the mainland,
Salvato (2012, pers. comm.) has found that the extant leafwing
population within ENP is maintained at several hundred individuals or
fewer, although numbers vary greatly depending upon season and other
factors. However, Minno (2009, pers. comm.) estimated the extant
leafwing population size at less than 100 at any given period.
Ongoing natural history studies of the leafwing by Salvato and
Salvato (Salvato 2012, pers. comm.) and Sadle (2013d, pers. comm.)
designed to evaluate mortality factors amongst the butterfly's immature
stages have identified a suite of predators, parasitoids, and pathogens
that may substantially influence annual variability.
Bartram's Scrub-Hairstreak--Based on the results of historical
(Baggett 1982, p. 80; Schwartz 1987, p. 16; Hennessey and Habeck 1991,
pp. 117-119; Smith et al. 1994, p. 118; Emmel et al. 1995, pp. 1-24;
Worth et al. 1996, pp. 62-65; Schwarz et al. 1996, pp. 59-61) and
recent (Salvato 1999, p. 1; 2001, p. 8; 2003, p. 53; Salvato and
Hennessey 2004, p. 223; Minno and Minno 2009, p. 76; Salvato and
Salvato 2010b, p. 154; Anderson 2012a, pers. comm.; Land 2012, pers.
comm.) surveys and natural history studies, there are extant Bartram's
scrub-hairstreak populations in ENP and locally within pineland
fragments in mainland Miami-Dade County, and on Big Pine Key in Monroe
County. Results from all known historical surveys are provided in Table
2. More recent studies are discussed below.
Table 2--Summary of Historical Bartram's Scrub-Hairstreak Surveys
----------------------------------------------------------------------------------------------------------------
Size or density
Population Ownership * Years numbers of adult Source
butterflies
----------------------------------------------------------------------------------------------------------------
National Key Deer Refuge--Big Federal--USFWS.... 1985-1986......... 20 observed or Schwartz (1987, p.
Pine Key. collected. 16).
National Key Deer Refuge--Big Federal--USFWS.... 1988-1989......... 3.9 per ha (1.6 Hennessey and
Pine Key. per ac). Habeck (1991, pp.
49-50).
Everglades National Park--Long Federal--NPS...... 1988-1989......... 0.5 per ha (0.2 Hennessey and
Pine Key. per ac). Habeck (1991, pp.
49-50).
Everglades National Park--Long Federal--NPS...... 1994-1995......... 7 observed........ Emmel et al.
Pine Key. (1995, p. 14).
National Key Deer Refuge--Big Federal--USFWS.... 1994-1995......... 9 observed........ Emmel et al.
Pine Key. (1995, p. 14).
National Key Deer Refuge--Big Federal--USFWS.... 1997-1998......... 4.3 per ha (1.7 Salvato (1999, p.
Pine Key. per ac). 52).
Everglades National Park--Long Federal--NPS...... 1997-1998......... 0 per ha (0 per Salvato (1999, p.
Pine Key. ac). 60).
----------------------------------------------------------------------------------------------------------------
* USFWS--U.S. Fish and Wildlife Service; NPS--National Park Service.
Ongoing surveys by Salvato and Salvato (unpublished data) indicate
the average number of adult Bartram's scrub-hairstreaks recorded
annually on Big Pine Key has declined considerably, from a high of 19.3
per ha (7.7 per ac) in 1999, to a low of less than 1 per ha (0.3 per
ac) in 2011, based on monthly (1999-2006) or quarterly (2007 to 2012)
surveys.
Hairstreaks often occur at low densities, fly erratically and are
small, making them inherently difficult to monitor (Henry 2013, pers.
comm.). Since early 2012, North Carolina State University personnel
have collaborated with the Service on techniques to improve detection
probabilities, estimate abundances, and measure vegetation
characteristics associated with butterfly populations on the NKDR
[[Page 47230]]
(Henry and Haddad 2013, p. 1). These studies have documented a mean
monthly count across sites ranging from 0.0 to 2.8 (with a standard
error of 0.33) adult hairstreaks per ha (Anderson 2012a,
pers. comm.). During 2013, using these survey techniques, NKDR
documented a peak abundance of 159 adults in the early summer months
(Anderson 2014, pers. comm.). Future monitoring efforts on NKDR will
include counts in both currently and historically occupied areas.
Salvato and Salvato (2010b, p. 159) and Salvato (2014, pers. comm.)
have encountered as many as 6.3 adult Bartram's scrub-hairstreaks per
ha (2.5 per ac) annually from 1999 to 2013, based on monthly surveys in
Long Pine Key. Ongoing surveys conducted by ENP staff from 2005 to
present have encountered a total of approximately 24 and 30 hairstreak
adults and larvae, respectively, throughout Long Pine Key (Land 2012,
pers. comm.; Sadle 2013b, pers. comm.).
Additional pine rockland fragments within Miami-Dade County that
are known to maintain small, localized populations of pineland croton
and sporadic occurrences of Bartram's scrub-hairstreak, based on
limited survey work, include: Navy Wells (120 ha (297 acres)), Camp
Owaissa Bauer (39 ha (99 ac)) (owned and managed by Miami-Dade County),
and several parcels within the Richmond Pine Rocklands, including:
Larry and Penny Thompson Memorial Park (109 ha (270 ac)), Zoo Miami
Preserve (300 ha (740 ac)), Martinez Pineland Park (53 ha (132 ac)),
and U.S. Coast Guard lands in Homestead (29 ha (72 ac)) (Minno and
Minno 2009, pp. 70-76; Possley 2010, pers. comm.). Adult butterflies
have also been observed within Zoo Miami (Cook 2013, pers. comm.).
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 list a species based
on any 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.
Factor A--The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
Habitat Loss
The Florida leafwing and Bartram's scrub-hairstreak have
experienced substantial destruction, modification, and curtailment of
their habitat and range (see Status Assessment section). The pine
rockland community of south Florida, on which both butterflies and
their hostplant depend, is critically imperiled globally (FNAI 2012, p.
27). Destruction of the pinelands for economic development has reduced
this habitat community by 90 percent on mainland south Florida
(including within ENP) (O'Brien 1998, p. 208). All known mainland
populations of the Florida leafwing and Bartram's scrub-hairstreak
occur on publicly or privately owned lands that are managed for
conservation (Table 3). However, any unknown extant populations of
these butterflies or suitable habitat that may occur on private land or
nonconservation public land, such as within the Richmond Pine
Rocklands, are vulnerable to habitat loss.
Table 3--Land Ownership of Extant Florida Leafwing and Bartram's Scrub-
Hairstreak Populations
------------------------------------------------------------------------
Location Ownership Size
------------------------------------------------------------------------
Bartram's scrub-hairstreak
------------------------------------------------------------------------
Big Pine Key................... Public--Fish and 559 ha (1,382 ac).
Wildlife Service.
Public--Monroe
County.
Public--FDEP *, FWC
*..
Private............
Everglades National Park--Long Federal--National 8,029 ha (19,840
Pine Key. Park Service. ac).
Navy Wells Pineland Preserve... Public--Miami-Dade 120 ha (296 ac).
County.
Camp Owaissa Bauer............. Public--Miami-Dade 40 ha (99 ac).
County.
Richmond Pine Rocklands........ Public--Federal 359 ha (889
(U.S. Coast Guard). acres).
------------------------------------------------------------------------
Public--Miami-Dade
County (Larry and
Penny Thompson
Memorial Park,
Martinez Pineland
Park, Miami Metro
Zoo Preserve).
Private--University
of Miami.
------------------------------------------------------------------------
Florida Leafwing
------------------------------------------------------------------------
Everglades National Park--Long Federal--National 8,029 ha (19,840
Pine Key. Park Service. ac).
------------------------------------------------------------------------
* FDEP--Florida Department of Environmental Protection; FWC--Florida
Fish and Wildlife Conservation Commission.
Similarly, most of the ecosystems on the Florida Keys have been
impacted by humans, through widespread clearing of habitat in the 19th
century for farming, or building of homes and businesses; extensive
areas of pine rocklands have been lost (Hodges and Bradley 2006, p. 6).
Overall, the human population in Monroe County is expected to increase
from 79,589 to more than 92,287 people by 2060 (Zwick and Carr 2006, p.
21). All vacant land in the Florida Keys is projected to be developed
by then, including lands currently inaccessible for development, such
as islands not attached to the Overseas Highway (US 1) (Zwick and Carr
2006, p. 14). However, during 2006, Monroe County implemented a Habitat
Conservation Plan (HCP) for Big Pine and No Name Keys. Subsequently,
development on these islands has to meet the requirements of the HCP
with the resulting pace of development changed
[[Page 47231]]
accordingly. Furthermore, in order to fulfill the HCP's mitigation
requirements, the County has been actively acquiring parcels of high-
quality pine rockland, such as The Nature Conservancy's 20-acre
Terrestris Tract on Big Pine Key, and managing them for conservation.
However, land development pressure and habitat losses may resume when
the HCP expires in 2023. If the HCP is not renewed, residential or
commercial development could increase to pre-HCP levels. Consequently,
remaining suitable habitat for Bartram's scrub-hairstreak and potential
habitat for the Florida leafwing could be at significant risk to
habitat loss and modification. Further losses will seriously affect the
hairstreak's ability to persist in the wild and decrease the
possibility of recovery or recolonization by the leafwing.
Fire Management
The threat of habitat destruction or modification is further
exacerbated by a lack of adequate fire management (Salvato and Salvato
2010a, p. 91; 2010b, p. 154; 2010c, p. 139). Historically, lightning-
induced fires were a vital component in maintaining native vegetation
within the pine rockland ecosystem, including pineland croton (Loope
and Dunevitz 1981, p. 5; Slocum et al. 2003, p. 93; Snyder et al. 2005,
p. 1; Salvato and Salvato 2010b, p. 154). Resprouting after burns is
the primary mechanism allowing for the persistence of perennial shrubs,
including pineland croton, in pine habitat (Olson and Platt 1995, p.
101). Without fire, successional climax from tropical pineland to
hardwood hammock is rapid, and displacement of native species by
invasive nonnative plants often occurs.
Cyclic and alternating treatment of burn units may have benefited
the Florida leafwing throughout Long Pine Key (Salvato and Salvato
2010a, pp. 91-97). The leafwing, with its strong flight abilities, can
disperse to make use of adjacent patches of hostplant and then quickly
recolonize burned areas following hostplant resurgence (Salvato 1999,
p. 5; 2003, p. 53; Salvato and Salvato 2010a, p. 95). Salvato and
Salvato (2010a, p. 95) encountered similar adult leafwing densities
pre- and post-burn throughout their 10-year study within Long Pine Key,
suggesting the leafwing can quickly recolonize pine rocklands following
a fire. Surveys conducted shortly after burns often found adult
leafwings actively exploring the recently burned locations in search of
new hostplant growth (Land 2009, pers. comm.; Salvato and Salvato 2008,
p. 326; 2010a, p. 95). In most instances croton returned to the burned
parts of Long Pine Key within 1 to 3 months post-burn; however, it may
take up to 6 months before the leafwing will use the new growth for
oviposition (Lenczewski 1980, p. 35; Land 2009, pers. comm.; Salvato
and Salvato 2010a, p. 95). Land (2009, pers. comm.) indicated that 96
percent of pineland croton burned during prescribed burns on Long Pine
Key had resprouted within a few months. Although Salvato and Salvato
(2010a, p. 96) occasionally encountered signs of leafwing reproduction
within recently burned Long Pine Key locations at approximately 6 weeks
post-burn, the majority of their observations indicated that
oviposition and larval activity increased at about 3 to 6 months post-
burn. Similarly, Land (2009, pers. comm.) reported finding leafwing
larval activity on resprouting croton at 6 months post-burn. This
finding suggests there may be some lag time between hostplant
resurgence and compatibility with recolonization. However, observations
of the Florida leafwing and Bartram's scrub-hairstreak within portions
of Long Pine Key that have experienced fire or other disturbance
regimes at intervals of up to 10 years (Salvato and Salvato 2010a;
2010b; Sadle 2013c, pers. comm.) suggest further studies are required
on the influence of disturbance regime on butterfly ecologies.
The influence of prescribed burns on the status and distribution of
the hairstreak and croton is being evaluated by ENP throughout Long
Pine Key. The effects of new burn techniques on the Bartram's scrub-
hairstreak within Long Pine Key were not immediately obvious (Salvato
and Salvato 2010b, p. 159). The hairstreak is rarely encountered more
than 5 m (16.4 ft) from its hostplant (Schwartz 1987, p. 16; Worth et
al. 1996, p. 65; Salvato and Salvato 2008, p. 324). Although further
studies may be required to determine how the hairstreak responds to
natural disturbances, Salvato and Hennessey (2004, p. 224) and Salvato
and Salvato (2010b, p. 159) indicate that, if the hairstreak is unable
to disperse adequately during fire events, then only adults at the
periphery of burned areas are likely to escape to adjacent pine
rocklands. Ideally, as a result of cyclic burns and multiyear treatment
intervals, the hairstreaks will move from the burned location to
adjacent refugia (i.e., unburned areas of croton hostplant) and then
back to the burned area in numbers equal to or greater than before the
fire. Starting in the fall of 2004 and continuing into early 2006, the
hairstreak appeared to have benefited from prescribed burns with
population densities greater than those recorded in any previous
studies (Salvato and Salvato 2010b, p. 159), and this trend has
continued subsequently (Land 2011, 2012a, pers. comm.; Salvato 2012,
pers. comm.).
ENP is actively coordinating with the Service, as well as other
members of the Imperiled Butterflies of Florida Workgroup, to review
and adjust the prescribed burn practices outlined in ENP's Fire
Management Plan (FMP) to help maintain or increase Florida leafwing and
Bartram's scrub-hairstreak population sizes, protect pine rocklands,
expand or restore remnant patches of hostplants and ensure that short-
term negative effects from fire (i.e., loss of hostplants, loss of eggs
and larvae) can be avoided or minimized. Revisions to the FMP are
expected to be completed in early 2014, with prescribed burn activities
resuming at that time.
Outside of ENP, Miami-Dade County has implemented various
conservation measures, such as burning in a mosaic pattern and on a
small scale, during prescribed burns in order to protect the
butterflies (Maguire 2010, pers. comm.). Miami-Dade County Parks and
Recreation staff has burned several of their conservation lands on a
fire-return interval of approximately 3 to 7 years. In addition,
prescribed burns on large conservation areas, such as Navy Wells, have
been conducted in a cyclic and systematic pattern, which has provided
refugia within or adjacent to treatment areas. As a result, the
Bartram's scrub-hairstreak has retained populations within many of
these County-managed conservation lands.
Recent natural or prescribed burn activity on Big Pine Key and
adjacent islands within NKDR appears to be insufficient to prevent loss
of pine rockland habitat (Carlson et al. 1993, p. 914; Bergh and Wisby
1996, pp. 1-2; O'Brien 1998, p. 209; Snyder et al. 2005; Bradley and
Saha 2009, pp. 28-29; Saha et al. 2011, pp. 169-184). As a result, many
of the pine rocklands, across NKDR are being compromised by succession
to hardwood hammock (Bradley and Saha 2009, pp. 28-29; Saha et al.
2011, pp. 169-184). Pineland croton, which was historically documented
from No Name and Little Pine Keys (Dickson 1955, p. 98; Hennessey and
Habeck 1991, p. 4; Carlson et al. 1993, p. 923), is now absent from
these locations (Emmel et al. 1995, p. 6; Salvato and Salvato 2010c, p.
139).
Fire management of pine rocklands in NKDR is hampered by the
pattern of land ownership and development;
[[Page 47232]]
residential and commercial properties are embedded within or in close
proximity to pineland habitat (Snyder et al. 2005, p. 2; Anderson
2012a, pers. comm.). As a result, hand or mechanical vegetation
management may be necessary at select locations on Big Pine Key (Emmel
et al. 1995, p. 11; Minno 2009, pers. comm.; Service 2010, pp. 1-68) to
maintain or restore pine rocklands. Clearing, such as that used to
create firebreaks, can result in high croton densities. Anderson et al.
(2012, page numbers not applicable) showed that croton densities were
significantly higher in a fire break with annual mechanical treatments
than adjacent areas with no management. However, even within fire
breaks, hostplant density across NKDR has declined considerably in some
areas over the past decade. Salvato and Salvato (unpublished data) have
noted as much as a 100 percent loss of pineland croton from several of
their long-term survey transects, which occur within both firebreaks
and forested pine rocklands. These losses are believed to be due to a
combination of mowing activity, habitat modification, and a lack of
adequate fire management. Ongoing and future studies on NKDR will be
designed to measure the influence of prescribed burns and other
management actions, such as mechanical clearing. Mechanical treatments
may be less beneficial than fire because they do not quickly convert
debris to nutrients, and remaining leaf litter may suppress croton
seedling development; fire has also been found to stimulate seedling
germination (Anderson 2010, pers. comm.). Because mechanical treatments
may not provide the same ecological benefits as fire, NKDR continues to
focus efforts on conducting prescribed burns where possible (Anderson
2012a, pers. comm.). Additional proposed experimental techniques that
will be designed to simulate disturbance include complete vegetation
removal (or scarping), fertilization (simulating the release of
nutrients after fire), or other treatments that mimic fire influence
(Haddad 2013, pers. comm., Anderson 2014, pers. comm.).
The NKDR is attempting to increase the density of hostplants within
their pine rockland habitat through the use of prescribed burns.
However, the majority of pine rocklands within NKDR are several years
departed from the ideal fire-return interval (5-7 years) suggested for
this ecosystem (Synder et al. 2005, p. 2, Saha et al. 2011, pp. 169-
184). Tree ring and sediment data show that pine rocklands in the lower
Keys have burned at least every 5 years and sometimes up to three times
per decade historically (Albritton 2009, p. 123, Horn et.al., 2013, pp.
1-67, Harley 2012, pp. 1-246). Prescribed burn implementation in the
lower Keys has been hampered largely due to a shortage of resources,
technical challenges, and expense of conducting prescribed burns in a
matrix of public and private ownership. However, NKDR is taking steps
to monitor croton before and after fire, provide refugia during
treatments, and ensure that appropriate corridors are maintained during
burns (Anderson 2010, pers. comm.). Given the difficulties in
prescribed burn implementation on Big Pine Key, other options have been
explored to increase the amount of available hostplant for extant
Bartram's scrub-hairstreak populations, as well as to restore formerly
occupied Florida leafwing habitat on Big Pine Key. For example, NKDR
currently is growing pineland croton for use in habitat enhancement
activities across the Refuge (more than a thousand have been planted to
date) (Anderson 2012b, pers. comm.).
Climate Change and Sea Level Rise Related to Habitat Loss and
Alteration
Climatic changes, including sea level rise, are major threats to
south Florida, and to the Florida leafwing and Bartram's scrub-
hairstreak. Our analyses under the Act include consideration of ongoing
and projected changes in climate. The terms ``climate'' and ``climate
change'' are defined by the Intergovernmental Panel on Climate Change
(IPCC). The term ``climate'' refers to the mean 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 2007a, 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
2007a, p. 78).
Scientific measurements spanning several decades demonstrate that
changes in climate are occurring, and that the rate of change has been
faster since the 1950s. Examples include warming of the global climate
system, and substantial increases in precipitation in some regions of
the world and decreases in other regions. For these and other examples,
see IPCC 2007a, p. 30; and Solomon et al. 2007, pp. 35-54, 82-85.
Results of scientific analyses presented by the IPCC show that most of
the observed increase in global average temperature since the mid-20th
century cannot be explained by natural variability in climate, and is
``very likely'' (defined by the IPCC as 90 percent or higher
probability) due to the observed increase in greenhouse gas (GHG)
concentrations in the atmosphere as a result of human activities,
particularly carbon dioxide emissions from use of fossil fuels (IPCC
2007a, pp. 5-6 and figures SPM.3 and SPM.4; Solomon et al. 2007, pp.
21-35). Further confirmation of the role of GHGs comes from analyses by
Huber and Knutti (2011, p. 4), who concluded it is extremely likely
that approximately 75 percent of global warming since 1950 has been
caused by human activities.
Scientists use a variety of climate models, which include
consideration of natural processes and variability, as well as various
scenarios of potential levels and timing of GHG emissions, to evaluate
the causes of changes already observed and to project future changes in
temperature and other climate conditions (e.g., Meehl et al. 2007,
entire; Ganguly et al. 2009, pp. 11555, 15558; Prinn et al. 2011, pp.
527, 529). All combinations of models and emissions scenarios yield
very similar projections of increases in the most common measure of
climate change, average global surface temperature (commonly known as
global warming), until about 2030. Although projections of the
magnitude and rate of warming differ after about 2030, the overall
trajectory of all the projections is one of increased global warming
through the end of this century, even for the projections based on
scenarios that assume that GHG emissions will stabilize or decline.
Thus, there is strong scientific support for projections that warming
will continue through the 21st century, and that the magnitude and rate
of change will be influenced substantially by the extent of GHG
emissions (IPCC 2007a, pp. 44-45; Meehl et al. 2007, pp. 760-764 and
797-811; Ganguly et al. 2009, pp. 15555-15558; Prinn et al. 2011, pp.
527, 529). See IPCC (2007b, p. 8), for a summary of other global
projections of climate-related changes, such as frequency of heat waves
and changes in precipitation. Also see IPCC 2011 (entire) for a summary
of observations and projections of extreme climate events.
Various changes in climate may 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 interactions of climate with other variables
(e.g., habitat fragmentation)
[[Page 47233]]
(IPCC 2007, pp. 8-14, 18-19). Identifying likely effects often involves
aspects of climate change vulnerability analysis. Vulnerability refers
to the degree to which a species (or system) is susceptible to, and
unable to cope with, adverse effects of climate change, including
climate variability and extremes. Vulnerability is a function of the
type, magnitude, and rate of climate change and variation to which a
species is exposed, its sensitivity, and its adaptive capacity (IPCC
2007a, p. 89; see also Glick et al. 2011, pp. 19-22). There is no
single method for conducting such analyses that applies to all
situations (Glick et al. 2011, p. 3). We use our expert judgment and
appropriate analytical approaches to weigh relevant information,
including uncertainty, in our consideration of various aspects of
climate change.
Global climate projections are informative, and, in some cases, the
only or the best scientific information available for us to use.
However, projected changes in climate and related impacts can vary
substantially across and within different regions of the world (e.g.,
IPCC 2007a, pp. 8-12). Therefore, we use ``downscaled'' projections
when they are available and have been developed through appropriate
scientific procedures, because such projections provide higher
resolution information that is more relevant to spatial scales used for
analyses of a given species (see Glick et al. 2011, pp. 58-61, for a
discussion of downscaling).
With regard to our analysis for the Florida leafwing and Bartram's
scrub-hairstreak, downscaled projections suggest that 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 0.224
centimeters (cm) (0.088 in) annually between 1913 and 2006 (National
Oceanographic and Atmospheric Administration (NOAA) 2008, p. 1). This
equates to approximately 22.3 cm (8.76 in) over the last 100 years
(NOAA 2008, p. 1). IPCC (2008, p. 28) emphasized it is very likely that
the average rate of sea level rise during the 21st century will exceed
that rate, although it was projected to have substantial geographical
variability.
Other processes to be affected by projected warming include
temperatures, rainfall (amount, seasonal timing, and distribution), and
storms (frequency and intensity). The Massachusetts Institute of
Technology (MIT) modeled several scenarios combining 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,
indicate significant effects on the Florida Keys.
The Nature Conservancy (TNC) modeled several scenarios for the
Florida Keys, and predicted that sea level rise will first result in
the conversion of habitat, and eventually the complete inundation of
habitat. In the best-case scenario, by the year 2100, a rise of 18 cm
(7 in) would result in the inundation of 745 ha (1,840 ac) (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 140 cm
(4.6 ft) would result in the inundation of about 2,409 ha (5,950 ac)
(96 percent) and the loss of all upland habitat on the Key (TNC 2010,
p. 1). Extant populations of Bartram's scrub-hairstreak in the pine
rocklands on Big Pine Key are located just slightly above mean sea
level, and saturation or increase in salinity of the soil would
correspondingly change the vegetation and habitat structure making the
butterfly's survival at this location in the Keys very unlikely (Minno
2013, page numbers not applicable). In addition, the Florida leafwing
also occurred on Big Pine Key until 2006, within the same locations as
extant Bartram's scrub-hairstreak populations. Reestablishment of the
Florida leafwing to this island will be a major component in recovering
the butterfly. The loss of this portion of the Florida leafwing's range
will further reduce their overall resiliency to threats and limit their
capacity for survival and recovery.
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. From the 1930s to
1950s, 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). Furthermore, Ross et
al. (2009, pp. 471-478) suggested that interactions between sea level
rise and pulse disturbances (e.g., storm surges) can cause vegetation
to change sooner than projected based on sea level alone. Alexander
(1953, pp. 133-138) attributed the demise of pinelands on northern Key
Largo to salinization of the groundwater in response to sea level rise.
Patterns of human development will also likely be significant factors
influencing whether natural communities can move and persist (IPCC
2008, p. 57; CCSP 2008, p. 7-6).
Drier conditions and increased variability in precipitation
associated with climate change are expected to hamper successful
regeneration of forests and cause shifts in vegetation types through
time (Wear and Greis 2011, p. 58). Climate changes are forecasted to
extend fire seasons and the frequency of large fire events throughout
the Coastal Plain (Wear and Greis 2011, p. 65). Increases in the scale,
frequency, or severity of wildfires could also have severe
ramifications on the Florida leafwing and Bartram's scrub-hairstreak,
considering their dependence on pine rocklands and general
vulnerability due to their reduced population size, restricted range,
few colonies, low fecundity, and relative isolation (see Factor E).
The ranges of recent projections of global sea level rise (Pfeffer
et al. 2008, p. 1340; Vermeer and Rahmstorf 2009, p. 21530; Grinsted et
al. 2010, pp. 469-470; Jevrejeva et al. 2010, Global Climate Change
Impacts in the United States 2009, pp. 25-26) 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 0.9 to 1.2 m (3 to 4 ft)) from
the low to the high ends of the ranges, which indicates that the
magnitude of global mean sea level rise at the end of this century is
still quite uncertain.
Alternative Future Landscape Models
Various model scenarios developed at MIT have projected possible
trajectories of future transformation of the south Florida landscape by
2060 based upon four main drivers: Climate change, shifts in planning
approaches and regulations, human population change, and variations in
financial resources for conservation (Vargas-Moreno and Flaxman 2010,
pp. 1-6). The Service used various MIT scenarios in combination with
extant and historical Florida leafwing and Bartram's scrub-hairstreak
occurrences and remaining hostplant-bearing pine rocklands to predict
what may occur to the butterflies and their habitat.
In the best-case scenario, which assumes low sea level rise, high
financial resources, proactive planning, and only trending population
growth, analyses suggest that the Big Pine Key
[[Page 47234]]
population of the Bartram's scrub-hairstreak may be lost or greatly
reduced. Based upon the above assumptions, extant butterfly populations
on Big Pine Key (Bartram's scrub-hairstreak) and Long Pine Key (Florida
leafwing and Bartram's scrub-hairstreak) appear to be most susceptible
for future losses, with losses attributed to increases in sea level and
human population. In the worst-case scenario, which assumes high sea
level rise, low financial resources, a `business as usual' approach to
planning, and a doubling of human population, the habitat at Big Pine
Key and Long Pine Key may be lost, with the loss of habitat at Long
Pine Key resulting in the complete extirpation of the Florida leafwing.
Under the worst-case scenario, pine rockland habitat would remain
within both Navy Wells and the Richmond Pine Rocklands, both of which
currently retain Bartram's scrub-hairstreak populations. Actual impacts
may be greater or less than anticipated based upon high variability of
factors involved (e.g., sea level rise, human population growth) and
assumptions made.
Everglades Restoration
Projects designed to restore the historical hydrology of the
Everglades and other natural systems in southern Florida (collectively
known as the Comprehensive Everglades Restoration Plan (CERP)) may
produce collateral impacts to extant pine rockland within Long Pine
Key. Salvato (2012, pers. comm.) noted substantial flooding of pine
rocklands at the gate 11 nature trail in Long Pine Key following
Hurricane Isaac (August 2012) and subsequent above-average rainfall in
the region. Although Long Pine Key has experienced storm damages in the
recent past (Salvato and Salvato 2010a, p. 96), none of the prior
activity produced the level (several feet) or duration (more than 2
months) of inundation noted in the aftermath of Isaac. However, by mid-
December 2012, Salvato noted no apparent lasting influence on croton
health or abundance from the inundation. Sadle (2012, pers. comm.)
suggests various CERP projects (C-111 spreader canal; L-31N seepage
barrier), specifically the operation of pumps and associated detention
areas along the ENP boundary, may influence select portions of eastern
Long Pine Key, including pineland croton populations at gate 11.
However, Pace (2013, pers. comm.) attributed the pine rockland flooding
event of late 2012 more to localized and above-average rainfall
patterns than to a change in water management practices. Analysis of
the hydrology associated with operation of these CERP-related
structures along the Everglades boundary will be conducted following
the initial years of operation. However, Service and National Park
Service (NPS) biologists realize the need to assess this potential
threat.
Conservation Efforts To Reduce the Present or Threatened Destruction,
Modification, or Curtailment of Its Habitat or Range
The National Wildlife Refuge System Improvement Act of 1997 and the
Fish and Wildlife Service Manual (601 FW 3, 602 FW 3) require
maintaining biological integrity and diversity, comprehensive
conservation planning for each refuge, and set standards to ensure that
all uses of refuges are compatible with their purposes and the Refuge
System's wildlife conservation mission. The comprehensive conservation
plans (CCP) address conservation of fish, wildlife, and plant resources
and their related habitats, while providing opportunities for
compatible wildlife-dependent recreation uses. An overriding
consideration reflected in these plans is that fish and wildlife
conservation has first priority in refuge management, and that public
use be allowed and encouraged as long as it is compatible with, or does
not detract from, the Refuge System mission and refuge purpose(s). The
CCP for the Lower Florida Keys National Wildlife Refuges (NKDR, Key
West National Wildlife Refuge, and Great White Heron National Wildlife
Refuge) provides a description of the environment and priority resource
issues that were considered in developing the objectives and strategies
that guide management over the next 15 years. The CCP promotes the
enhancement of wildlife populations by maintaining and enhancing a
diversity and abundance of habitats for native plants and animals,
especially imperiled species that are found only in the Florida Keys.
The CCP also provides for obtaining baseline data and monitoring
indicator species to detect changes in ecosystem diversity and
integrity related to climate change. In the Lower Key Refuges, CCP
management objective 11 provides specifically for maintaining and
restoring butterfly populations of special conservation concern,
including the Bartram's scrub-hairstreak and Florida leafwing
butterflies.
As Federal candidates, the Florida leafwing and Bartram's scrub-
hairstreak are afforded some protection through sections 7 and 10 of
the Act and associated policies and guidelines. Service policy requires
candidate species be treated as proposed species for purposes of intra-
Service consultations and conferences where the Service's actions on
National Wildlife Refuges may affect candidate species. Federal action
agencies (e.g., the Service, NPS) are to consider the potential effects
of their activities (e.g., prescribed burning, pesticide treatments) to
these butterflies and their habitat during the consultation and
conference 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. However,
candidate species do not receive the same level of protection that a
listed species would under the Act.
The NPS is also currently preparing a revised General Management
Plan (GMP) for ENP (Sadle 2013a, pers. comm.). ENP's current Management
Plan (initiated in 1979) serves to protect, restore, and maintain
natural and cultural resources at the ecosystem level (NPS 2000, p.
10). The current GMP is not regulatory, and its implementation is not
mandatory. In addition, this GMP does not specifically address either
the Florida leafwing or Bartram's scrub-hairstreak.
Fairchild Tropical Botanic Gardens (FTBG), with the support of
various Federal, State, local, and nonprofit organizations, has
established the ``Connect to Protect Network.'' The objective of this
program is to encourage widespread participation of citizens to create
corridors of healthy pine rocklands by planting stepping-stone gardens
and rights-of-way with native pine rockland species, and restoring
isolated pine rockland fragments. By doing this, FTBG hopes to increase
the probability that pollinators can find and transport seeds and
pollen across developed areas that separate pine rocklands fragments to
improve gene flow between fragmented plant populations and increase the
likelihood that these species will persist over the long term. Although
this project may serve as a valuable component toward the conservation
of pine rockland species, it is dependent on continual funding, as well
as participation from private landowners, both of which may vary
through time.
Factor 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
[[Page 47235]]
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 (McKissick 2011,
pers. comm.).
In the past, when the Florida leafwing and Bartram's scrub-
hairstreak were widespread on Big Pine Key and throughout southern
Miami-Dade County, collecting likely exerted little pressure on these
butterfly populations. At present, even limited collection from the
small, remaining populations could have deleterious effects on
reproductive and genetic viability and thus could contribute to their
eventual extinction (see Factor E--Effects of Few, Small Populations
and Isolation, below). Collection, which is prohibited on conservation
lands, could occur (e.g., ENP, NKDR, State or County owned lands)
without being detected, because these areas are all not actively
patrolled (see Factor D--The Inadequacy of Existing Regulatory
Mechanisms, below). Similarly, in some areas such as on Big Pine Key,
where numerous pine rockland parcels within NKDR are interspersed among
residential areas, there is no signage indicating that collection is
prohibited (Salvato 2012, pers. comm.). Consequently, the potential for
collection of eggs, larvae, pupae, and adult butterflies exists, and
such collection could go undetected, despite the protection provided on
Federal or other public lands.
We have direct evidence of interest in the collecting, as well as
proposed commercial sale, of the Florida leafwing and Bartram's scrub-
hairstreak. Salvato (2011, pers. comm.) has also been contacted by
several individuals requesting specimens of the Florida leafwing, as
well as information regarding locations where both butterflies may be
collected in the field. Salvato (2012, pers. comm.) observed several
individuals collecting butterflies at Navy Wells during 2005, including
times when Bartram's scrub-hairstreak was present at this site.
We are also aware of multiple Web sites that offer or have offered
specimens of south Florida butterflies for sale that are candidates for
listing under the Act (Minno 2009, pers. comm.; Nagano 2011, pers.
comm.; Olle 2011, pers. comm.). 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 they were
collected, but this butterfly is now mainly restricted to ENP where
collection is prohibited. The same Web site currently offers specimens
of Bartram's scrub-hairstreak for [euro]10.00 ($13). It is unclear from
where these specimens originated or when they were collected. The
hairstreak can be found on private lands on Big Pine Key and perhaps
locally within Miami-Dade County. However, given that the majority of
known populations of both butterflies now occur within protected
Federal, State, and county lands, it is possible that some specimens
are being poached. Alternatively, Calhoun (2013, pers. comm.) suggests
that many specimens of the Florida leafwing and Bartram's scrub-
hairstreak offered from sale online or elsewhere may come from older
collections, as opposed to from poaching activities on conservation
lands.
Scientific Research
Some techniques (e.g., capture, handling) used to understand or
monitor the leafwing and hairstreak butterflies 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 injure individuals or damage habitat. Mark-recapture, a
common method used to determine population size, has been used by some
researchers to monitor Florida leafwing and Bartram's scrub-hairstreak
populations (Emmel et al. 1995, p. 4; Salvato 1999, p. 24). 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 (wing damage) or
kill butterflies or alter their behaviors (Mallet et al. 1987, pp. 377-
386; Murphy 1988, pp. 236-239). Salvato (2012, pers. comm.) ceased
using mark-recapture shortly after initiating his long-term leafwing
studies when he realized how much the tagging altered from the
butterflies' cryptic (camouflage) underside as individuals alit
(rested) on pineland foliage. Murphy (1988, p. 236) and Mattoni et al.
(2001, p. 198) indicated that studies on various lycaenids (small
butterflies known as hairstreaks and blues) 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). Cook (2013, pers. comm.) suggests that
marking individuals improves the accuracy of population estimates by
reducing sampling error from recounting or extrapolation. Emmel et al.
(1995, p. 4) conducted mark-recapture studies on the hairstreak and
noted no detrimental effects. In addition several individuals were re-
encountered (recaptured) during the days following marking. However,
researchers currently studying the populations of the endangered Miami
blue in the Florida Keys have opted not to use mark-release-recapture
techniques due to the potential for damage to this small, fragile
lycaenid (Haddad and Wilson 2011, p. 3).
Factor C--Disease or Predation
Florida Leafwing
A number of predators have been documented to impact Florida
leafwings throughout their life cycle. One of the earliest natural
history accounts of the leafwing (Matteson 1930, p. 8) reported ants as
predators of leafwing eggs in Miami. On Big Pine Key, Hennessey and
Habeck (1991, p. 17) encountered a pupa of the Florida leafwing being
[[Page 47236]]
consumed by ants. Land (2009, pers. comm.) observed a native twig ant
(Pseudomyrmex pallidus) carrying a young leafwing larva in Long Pine
Key. Salvato and Salvato (2012, p. 3) witnessed an older leafwing larva
repelling P. pallidus attacks while attempting to pupate. Minno (2009,
pers. comm.) noted that the larger nonnative graceful twig ant
(Pseudomyrmex gracilis) is also known to consume immature butterflies
and moths. Salvato and Salvato (2012, p. 3) have observed a graceful
twig ant attempting to capture a young leafwing larva. Cannon (2006,
pp. 7-8) reported high mortality of giant and Bahamian (P. a.
andraemon) swallowtail eggs from a nonnative species of twig ant
(Pseudomyrmex spp.) on Big Pine Key, within habitat formerly occupied
by the Florida leafwing. Both native and nonnative Pseudomyrmex ants
are abundant within Long Pine Key and are frequently encountered
patrolling the racemes of pineland croton. Forys et al. (2001, p. 257)
found high mortality among immature giant swallowtails (Papilio
cresphontes) from imported red fire ant (Solenopsis invicta) predation
in experimental trials and suggested other butterflies in southern
Florida might also be influenced.
Additional predators of immature Florida leafwings include spiders
(Rutkowski 1971, p. 137; Glassberg et al. 2000, p. 99; Salvato and
Salvato 2010e, p. 6; 2011, p. 103; 2012c, p. 3), ambush bugs (Salvato
and Salvato 2008, p. 324), and possibly mites (Salvato and Salvato
2010e, p. 6). Salvato and Salvato (unpublished data) have examined the
bite marks on wings of numerous adults in the field suggesting a
variety of birds and lizards are among the predators of this butterfly.
A number of parasites have been documented to impact Florida
leafwings throughout their life cycle. Hennessey and Habeck (1991, p.
16) and Salvato and Hennessey (2004, p. 247) noted that leafwing egg
mortality within ENP and Big Pine Key from trichogrammid wasp
(Trichogramma sp.) parasitism ranged from 70 to 100 percent. Salvato
and Salvato (2011, p. 2) continually encounter leafwing eggs that have
been attacked by trichogrammid wasps, suggesting this wasp remains a
consistent parasitoid for the leafwing within ENP.
Caldas (1996, p. 89), Muyshondt (1974, pp. 306-314), DeVries (1987,
p. 21), and Salvato and Hennessey (2003, p. 247) each indicated high
parasitism rates from tachinid flies for larvae of Anaea or similar
genera. Hennessey and Habeck (1991, p. 17) and Salvato et al. (2009, p.
101) each encountered Florida leafwing larvae within ENP that had been
parasitized by Chetogena scutellaris (Diptera: Tachinidae). Ongoing
studies of leafwing larvae in Long Pine Key have indicated that C.
scutellaris serves as a consistent mortality factor to the butterfly in
this part of its range (Salvato et al. 2009, p. 101; Salvato and
Salvato 2010a, p. 95). Current studies suggest that leafwing mortality
from the fly can vary considerably from year to year, thereby also
influencing overall population numbers of the butterfly. In 2011,
nearly all leafwing larvae observed to be parasitized by C.
scutellaris, died prior to pupation. Conversely, in winter of 2012,
three of four leafwing larvae observed to be heavily parasitized by the
fly were found to successfully pupate and emerge (Salvato and Salvato
2012, p. 3).
Salvato et al. (2008, p. 237) observed a biting-midge, Forcipomyia
(Microhelea) fuliginosa (Diptera: Ceratopogonidae), feeding on a young
Florida leafwing larva within ENP. Ongoing studies of F. (M.)
fuliginosa and a second biting midge F. (M.) eriophora (Salvato et al.
2012a, p. 232) indicate they consistently parasitize leafwing larvae
within Long Pine Key throughout their development.
Salvato and Salvato (2012, p. 1) and Sadle (2013d, pers. comm.)
have monitored Florida leafwing immature development in the field for
several years at Long Pine Key. To date these studies have measured
mortality rates of more than 70 percent for immature leafwing,
individuals dying from various parasites, predators, and other factors
such as fungal pathogens (Salvato and Salvato 2012, p. 1; Sadle 2013d,
pers. comm.). The majority of mortality noted thus far in these studies
has occurred in the earliest, immature stages. Caldas (2013, pers.
comm.) suggests that, based on the high mortality of immature leafwing,
often from natural factors such as parasitism, recovery efforts for
these butterflies should be focused on the adult stage, specifically
establishing and maintaining additional breeding populations.
Bartram's Scrub-Hairstreak
Native parasites and predators have been documented to impact
Bartram's scrub-hairstreaks. Hennessey and Habeck (1991, p. 19)
collected an older hairstreak larva on Big Pine Key from which a single
braconid wasp emerged during pupation. During 2010, Salvato et al.
(2012b, p. 113) encountered a hairstreak larva within Long Pine Key
that had been parasitized by C. scutellaris. These are the only known
records for a larval parasitoid on this butterfly. Tracking the fate of
hairstreak pupae is extremely difficult because they pupate in the
ground litter (Worth et al. 1996, p. 63). Collection of other
parasitized hairstreak larvae is needed to determine the influence of
parasitism on its early stages (Salvato and Hennessey 2004, p. 225).
Many immature lycaenids, including those of the endangered Miami blue,
demonstrate a symbiotic relationship with ants (Saarinen and Daniels
2006, p. 69; Trager and Daniels 2009, p. 474; Daniels 2013, pers.
comm.), as a strategy to ward off predation. However, no such symbiotic
relationship between Bartram's scrub-hairstreak larvae and ants has
been documented (Salvato 1999, p. 124).
Salvato and Salvato (2010d, p. 71) observed erythraeid larval mite
parasites on an adult Bartram's scrub-hairstreak in Long Pine Key.
Although mite predation on butterflies is rarely fatal (Treat 1975, pp.
1-362), the role of parasitism by mites in the natural history of the
hairstreak requires further study. Salvato and Salvato (2008, p. 324)
have observed dragonflies (Odonata) preying on adult hairstreaks. Crab
spiders, orb weavers, ants, and a number of other predators discussed
as mortality factors for the leafwing have also been frequently
observed on croton during hairstreak surveys and may also prey on
hairstreak adults and larvae (Salvato and Hennessey 2004, p. 225;
Salvato 2012, pers. comm.). NKDR biologists have witnessed nonnative
Cuban anoles (Anolis equestris) attempting to prey on adult Bartram's
scrub-hairstreaks (Anderson 2013, pers. comm.). Minno and Minno (2009,
p. 72) also cite nonnative predators such as ants as a major threat to
both butterflies.
Factor D--The Inadequacy of Existing Regulatory Mechanisms
Under this factor, we examine whether existing regulatory
mechanisms are inadequate to address the threats to the species
discussed under the other factors. Section 4(b)(1)(A) of the Act
requires the Service to take into account ``those efforts, if any,
being made by any State or foreign nation, or any political subdivision
of a State or foreign nation, to protect such species. . . .'' In
relation to Factor D, we interpret this language to require the Service
to consider relevant Federal, State, and Tribal laws, plans,
regulations, and other such mechanisms that may minimize any of the
threats we describe in threat analyses under the other four factors, or
otherwise enhance conservation of the species. We give strongest weight
to statutes and their
[[Page 47237]]
implementing regulations and to management direction that stems from
those laws and regulations. An example would be State governmental
actions enforced under a State statute or constitution, or Federal
action under statute.
Having evaluated the significance of the threat as mitigated by any
such conservation efforts, we analyze under Factor D the extent to
which existing regulatory mechanisms are inadequate to address the
specific threats to the species. Regulatory mechanisms, if they exist,
may reduce or eliminate the impacts from one or more identified
threats. In this section, we review existing State and Federal
regulatory mechanisms to determine whether they effectively reduce or
remove threats to the Florida leafwing and Bartram's scrub-hairstreak
butterflies.
Federal
Existing Federal regulatory mechanisms that could provide some
protection for the Florida leafwing and Bartram's scrub-hairstreak
butterflies include: (1) The National Park Service Organic Act and its
implementing regulations; (2) the National Wildlife Refuge System
Administration Act (16 U.S.C. 668dd-ee) as amended, and the Refuge
Recreation Act (16 U.S.C. 460k-460k-4) and their implementing
regulations.
National Park Service (NPS) regulations at 36 CFR 2.1 and 2.2
prohibit visitors from harming or removing wildlife, listed or
otherwise, from ENP. In addition, NPS regulation 36 CFR 2.5 prohibits
visitors from conducting research or collecting specimens without a
permit. Although ENP was not able to provide specific information
concerning poaching of butterflies or enforcement of NPS regulations
protecting the butterflies and their habitats from harm, the apparent
online sales of the butterflies suggests that poaching could be
occurring. Insufficient implementation or enforcement could become a
threat to the two butterflies in the future if they continue to decline
in numbers.
Special Use Permits (SUPs) are issued by the Refuges as authorized
by the National Wildlife Refuge System Administration Act (16 U.S.C.
668dd-ee) as amended, and the Refuge Recreation Act. The Service's
South Florida Ecological Services Office and NKDR coordinate annually
on potential impacts to the Florida leafwing and Bartram's scrub-
hairstreak prior to issuance of an SUP to the Florida Keys Mosquito
Control District (FKMCD) (see Factor E--Pesticides, below). In
addition, as discussed above (Factor A--Conservation Efforts To Reduce
the Present or Threatened Destruction, Modification, or Curtailment of
Its Habitat or Range), the CCP for the Lower Key Refuges provides
specifically for maintaining and restoring butterfly populations within
NKDR, including the Bartram's scrub-hairstreak and Florida leafwing
butterflies.
State
Neither the Florida leafwing nor Bartram's scrub-hairstreak
butterflies are currently listed by the State of Florida as a protected
species under Chapter 68A-27, Rules Relating to Endangered or
Threatened Species, so there are no existing State regulations
designated to protect them. However, all State-owned property and
resources 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.
Local
Under Miami-Dade County ordinance (Section 26-1), a permit is
required to conduct scientific research (Rule 9) on county
environmental lands. In addition, Rule 8 of this ordinance provides for
the preservation of habitat within County parks or areas operated by
the Parks and Recreation Department. We have no information to suggest
that other counties within the range of the leafwing and hairstreak
have regulatory mechanisms that provide any protections for these
butterflies.
Factor E--Other Natural or Manmade Factors Affecting Its Continued
Existence
Effects of Few, Small Populations and Isolation
The Florida leafwing and Bartram's scrub-hairstreak are vulnerable
to extinction due to their severely reduced range, reduced population
size, lack of metapopulation structure, few remaining populations, and
relative isolation. Abundance of the Florida leafwing and Bartram's
scrub-hairstreak is not known, but each butterfly is estimated to
number in the hundreds, and at times, possibly much lower. Although
highly dependent on individual species considered, a population of
1,000 has been suggested as marginally viable for an insect (Schweitzer
2003, pers. comm.). Schweitzer (2003, pers. comm.) has also suggested
that butterfly populations of fewer 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 the threats on the remaining
reduced population and limited remaining habitat. They found the
Fender's blue to be at high risk of extinction due to agriculture
practices, development activities, forestry practices, grazing,
roadside maintenance, and commercial Christmas tree farming.
Losses in diversity within populations of the Florida leafwing and
Bartram's scrub-hairstreak may have already occurred (Salvato 2012,
pers. comm.). The leafwing and hairstreak have been extirpated from
several locations where they were previously recorded (Baggett 1982,
pp. 78-81; Salvato and Hennessey 2003, p. 243; 2004, p. 223). Initially
described from Brickell Hammock in Coral Gables, Florida (present day
Vizcaya Museum and Gardens), in the 1940s (Salvato 2012, pers. comm.),
mainland populations of the leafwing have subsequently retreated with
the loss, fragmentation, and degradation of native pine rocklands
throughout Miami-Dade County (Baggett 1982, pp. 78-81; Salvato and
Hennessey 2003, p. 243). At present, the leafwing is extant only within
ENP, and ongoing surveys suggest the butterfly actively disperses
throughout the Long Pine Key region of the Park (Salvato and Salvato
2010a, p. 91; 2010c, p. 139). Once locally common at Navy Wells and the
Richmond Pine Rocklands (which occur approximately 8 and 27 km (5 and
17 mi) to the northeast of ENP, respectively), leafwings are not known
to have bred at either location in more than 25 years (Salvato and
Hennessey 2003, p. 243; Salvato 2012, pers. comm.). In the lower
Florida Keys, the leafwing had maintained a stronghold for many decades
on Big Pine Key, within NKDR, until 2006 when that
[[Page 47238]]
population disappeared due to a variety of factors (Salvato and Salvato
2010c, pp. 139-140).
The Bartram's scrub-hairstreak is extant within ENP, Navy Wells,
Camp Owaissa Bauer, Richmond Pine Rocklands, as well as on Big Pine Key
(Baggett 1982, pp. 80-81; Smith et al. 1994, pp. 118-119; Salvato and
Salvato 2010b, p. 154). However, given the possible limited dispersal
abilities of this butterfly, the distance between these sites, (Worth
et al. 1996, p. 63; Salvato and Hennessey 2004, p. 223) and their
fragmentation, it is unlikely there is any genetic exchange between
locations.
Another south Florida lycaenid, the Miami blue (Cyclargus thomasi
bethunebakeri), also appears to have been impacted by relative
isolation similar to that of the hairstreak. Over the past decade, this
blue butterfly was known from only two contemporary populations, Bahia
Honda Key and Key West National Wildlife Refuge. Saarinen (2009, p. 79)
suggested that the separation of genetic exchange between these extant
populations was only recent (within the past few decades). Despite
fluctuations in annual and seasonal population sizes, the Bahia Honda
blue population was thought to have retained an adequate amount of
genetic diversity to maintain the butterfly. However, as of 2010, the
Miami blue population on the island was extirpated.
Extant hairstreak populations are likely experiencing a similar
lack of continuity in genetic exchange given their current fragmented
distribution. 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). If only one or a
few 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. 2009, p. 36; See
Factors A-D above).
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 a highly inbred
population with low viability or fecundity (Chesser 1983, p. 68).
Natural fluctuations in rainfall, hostplant vigor, or predation may
weaken a population to such an extent that recovery to a viable level
would be impossible. Isolation of habitat can prevent recolonization
from other sites and result in extinction. The leafwing and hairstreak
are restricted to one (leafwing) or a few small (hairstreak) localized
populations. The extent of habitat fragmentation makes these
butterflies vulnerable to extinction.
Environmental Stochasticity
The climate of southern Florida and the Florida 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 1 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.
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 Florida leafwing and Bartram's scrub-hairstreaks' low
population sizes and few isolated occurrences within locations prone to
storm influences, these butterflies are 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 leafwing and hairstreak could become locally
extirpated or extinct as a result of one event.
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, hurricane frequency
should decrease by 10 to 30 percent, with a 5 to 10 percent wind
increase. This anticipated result is due to more hurricane energy
available for intense hurricanes. However, hurricane frequency is
expected to drop because more wind shear will impede 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 to 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.
The Florida leafwing and Bartram's scrub-hairstreak have adapted
over time to the influence of tropical storms and other forms of
adverse weather conditions (Minno and Emmel 1994, p. 671; Salvato and
Salvato 2007, p. 154). However, given the substantial reduction in the
historical range of these butterflies in the past 50 years, the threat
and impact of tropical storms and hurricanes on their remaining
populations is much greater than when their distribution was more
widespread (Salvato and Salvato 2010a, p. 96; 2010b, p. 157; 2010c, p.
139).
During late October 2005, Hurricane Wilma caused substantial damage
to the pine rocklands of northwestern Big Pine Key (Salvato and Salvato
2010c, p. 139), specifically within the Watson Hammock region of NKDR,
the historical stronghold for the Florida leafwing on the island. In
historical instances when leafwing and hairstreak population numbers
were larger on Big Pine, such as following Hurricane Georges in 1998,
these butterflies appeared able to recover soon after a storm (Salvato
and Salvato 2010c, p. 139). In ENP, where leafwing and hairstreak
densities remained stable, these butterflies were minimally affected by
the 2005 hurricane season (Salvato and Salvato 2010a, p. 96, 2010b, p.
157). However, for the leafwing, given its substantial decline on Big
Pine Key prior to Wilma, it is possible that the impact of this storm
[[Page 47239]]
served to further hinder and reduce extant populations of the butterfly
on the island (Salvato and Salvato 2010c, p. 139).
Environmental factors have likely impacted both butterflies and
their habitat within their historical and current ranges. For example,
unusually cold temperatures were encountered throughout southern
Florida during the winters of 2009 and 2010. Sadle (2009, pers. comm.)
noted frost damage on croton at ENP on Long Pine Key in late 2009, but
observed living larvae earlier that year, when temperatures were at or
barely above freezing (2.2 [deg]C; 36 [deg]F) and frost was on the
ground. Frost in winter 2010 resulted in substantial dieback of native
plants, including damage and widespread defoliation of the croton in
Long Pine Key (Sadle 2010, pers. comm.; Land 2010, pers. comm.; Hallac
et al. 2010, pp. 2-3). Fifty percent of the individual leafwing larvae
were impacted by the cold and observed to be dead or without nearby
food supplies within Long Pine Key (Hallac et al. 2010, p. 3). Although
Salvato and Salvato (2011, p. 2) did not record increased butterfly
larval mortality on their survey sites in ENP during early 2010, they
did encounter larvae on frost-killed plants and indicated that those
larvae unable to successfully reach healthier adjacent hostplants
likely perished.
During late 2010, Salvato and Salvato (2011, p. 2) noted increased
larval leafwing mortality on their survey sites due to a number of
factors, including cold. Sadle (2011, pers. comm.) also observed
significant leaf and stem damage to croton during the same time period.
A single dead leafwing larva was observed on a frost-damaged croton
plant, though it is unclear if the mortality was a direct or indirect
consequence of the freezing temperatures (Sadle 2011, pers. comm.).
Salvato and Salvato (2011, p. 2) examined several (n = 4) dark,
apparently frozen leafwing larvae during this time period, but later
determined these had likely been killed from tachinid fly parasitism
prior to the freeze. Sadle (2011, pers. comm.) and Salvato and Salvato
(2011, p. 2) noted living larvae following the late 2010 freeze,
largely in areas unaffected by the frost. From these observations,
Sadle (2011, pers. comm.) suggested that frost damage may produce
similar effects to loss of aboveground plant parts that results from
fire. It is not clear what the short- or long-term impacts of prolonged
cold periods may be on leafwing or hairstreak populations; however, it
is likely that prolonged cold periods have some negative impacts on
both the butterflies and their hostplant (Sadle 2010, pers. comm.; Land
2010, pers. comm.).
As described above (see Factor C), ongoing natural history studies
by Salvato and Salvato (2012, p. 1) indicate that the extant leafwing
population within Long Pine Key experiences up to 80 percent mortality
amongst immature larval stages. A similarly high mortality has been
noted for the endangered Schaus swallowtail in southern Florida (Emmel
1997, p. 11). Such high levels of mortality may explain why leafwing
population densities vary considerably from year to year. As with the
influence of tropical storms, population-level recoveries from high
rates of parasitism or other factors at a select location would
historically be offset from less-affected adjacent populations.
Opportunities for such population-level recovery are now severely
restricted (see ``Effects of Few, Small Populations and Isolation'' in
this section).
Pesticides
Efforts to control mosquitoes and other insect pests have increased
as human activity and population have increased in south Florida. To
control mosquito populations, 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) for mosquito control presents a
potential risk to nontarget species, such as the Florida leafwing and
Bartram's scrub-hairstreak.
The potential for mosquito control chemicals to drift into
nontarget areas and persist for varying periods of time has been
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
federally endangered Schaus swallowtail (Papilio aristodemus
ponceanus), as well as the Florida leafwing, Bartram's scrub-
hairstreak, and other imperiled species in both the upper (Crocodile
Lake National Wildlife Refuge, North Key Largo) and lower Keys (NKDR).
Residues of aerially applied naled were found 6 hours after application
in a pineland area that was 750 m (820 yards (yd)) from the target
area; residues of fenthion (an adulticide no longer used in the Keys)
applied via truck were found up to 50 m (55 yd) 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 low but measurable
amounts of permethrin in nontarget areas. In 2009, Bargar (2011, pers.
comm.) conducted two field trials on NKDR that detected significant
naled residues at locations within nontarget areas on the Refuge that
were up to 402 m (440 yd) from the edge of zones targeted for aerial
applications. After this discovery, the Florida Key Mosquito Control
District recalibrated the on-board model (Wingman[sscopy]). Naled
deposition was reduced in some of the nontarget zones following
recalibration (Bargar 2012b, p. 3).
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 moths and
butterflies have been attributed to fenthion and naled in both south
Florida and the Florida Keys (Emmel 1991, pp. 12-13; Eliazar and Emmel
1991, pp. 18-19; Eliazar 1992, pp. 29-30). Zhong et al. (2010, pp.
1961-1972) investigated the impact of single aerial applications of
naled on the endangered Miami blue butterfly larvae in the field.
Survival of butterfly larvae in the target zone was 73.9 percent, which
was significantly lower than in both the drift zone (90.6 percent) and
the reference (control) zone (100 percent), indicating that direct
exposure to naled poses significant risk to Miami blue larvae. Fifty
percent of the samples in the drift zone also exhibited detectable
concentrations, once again exhibiting the potential for mosquito
control chemicals to drift into nontarget areas. Bargar (2011, pers.
comm.) observed cholinesterase activity depression, to a level shown to
cause mortality in the laboratory, in great southern white and Gulf
fritillary
[[Page 47240]]
butterflies exposed to naled during an application on NKDR in both
target and nontarget zones.
In the lower Keys, Salvato (2001, pp. 8-14) suggested that declines
in populations of the Florida leafwing were also partly attributable to
mosquito control chemical applications. Salvato (2001, p. 14; 2002, pp.
56-57) found relative populations of the Florida leafwing, when extant
on Big Pine Key within NKDR, to increase during drier years when
adulticide applications over the pinelands decreased, although
Bartram's scrub-hairstreak did not follow this pattern. Salvato (2001,
p. 14) suggested that butterflies, such as the leafwing, were
particularly vulnerable to aerial applications based on their tendency
to roost within the pineland canopy, an area with maximal exposure to
aerial treatments. Because roosting sites for the Bartram's hairstreak
are not well documented, more study is needed to assess their potential
exposure. The role of vegetation in limiting exposure is unknown, but
could be important when considering that spraying operations are
conducted during early morning and late evening hours when, presumably,
nontarget butterflies would be occupying roost sites (Anderson 2013,
pers. comm.).
Toxicity data on Florida native butterflies exposed to permethrin
and naled in the laboratory (Hoang et al. 2011, pp. 997-1005) were used
to calculate hazard quotients (concentrations in the environment--
concentrations causing an adverse effect) in order to assess the risk
that concentrations of naled and permethrin found in the field pose to
butterflies. A hazard quotient where the environmental concentration is
greater than the concentration known to cause an adverse effect
(mortality in this case), indicates 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 Florida Keys. When using the
lowest median lethal concentrations from the laboratory study, the
hazard quotients for permethrin and naled indicated potential acute
hazards to butterflies. Bargar (2012a, pp. 5-6) also conducted a
probabilistic risk assessment using naled deposition values from NKDR
and estimated that field-measured naled concentrations did pose a risk
to adult butterflies of some species, particularly for species with
large surface area to weight ratios.
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).
Spraying practices by the Florida Keys Mosquito Control District
(FKMCD) at NKDR have changed to reduce pesticide use over the years. In
addition, larvicide treatments to surrounding islands have
significantly reduced adulticide use on Big Pine Key, No Name Key, and
the Torch Keys since 2003 (FKMCD 2012, p. 11). According to the Special
Use Permit issued by the Service, the number of aerially applied naled
treatments allowed on NKDR has been limited since 2008 (FKMCD 2012, pp.
10-11).
The Service's Integrated Pest Management (IPM) Policy (569 FW 1)
establishes procedures and responsibilities for pest management
activities on and off Service lands. These may include (1) preparing
pesticide use proposals (PUPs) for approval before applying pesticides;
(2) entering pesticide usage information annually into the online IPM
and Pesticide Use Proposal System (PUPS) database; (3) conducting
Endangered Species Act consultations; and (4) following National
Environmental Policy Act policies. Since these butterflies have been on
the candidate list, the Service's South Florida Ecological Services
Office and NKDR coordinate annually on potential impacts to the Florida
leafwing and Bartram's scrub-hairstreak prior to issuance of a PUP to
the FKMCD. Based on this consultation, 478 ha (1,180 ac) of the 705 ha
(1,741 ac) of pine rockland in the NKDR have been designated no-spray
zones by agreement (as of May 2012) between the Service and FKMCD that
includes the core habitat used by pine rockland butterflies (Anderson
2012a, pers. comm.; Service 2012, p. 32). In addition, several linear
miles of pine rockland habitat within the Refuge-neighborhood interface
were excluded from truck spray applications in the most sensitive
habitats. These exclusions and buffer zones encompass over 95 percent
of extant croton distribution on Big Pine Key, and include the majority
of known extant and historical Florida leafwing and Bartram's scrub-
hairstreak population centers on the island (Salvato 2012, pers.
comm.). However, some areas of pine rocklands within NKDR are still
sprayed with naled (aerially applied adulticide), and buffer zones
remain at risk from drift. Additionally, private residential areas and
roadsides across Big Pine Key are treated with permethrin (ground-based
applied adulticide) (Salvato 2001, p. 10). Therefore, the hairstreak
and, if extant, the leafwing and their habitat on Big Pine Key may be
directly or indirectly (via drift) exposed to adulticides used for
mosquito control at some unknown level. Although there is evidence that
mosquito control practices may influence butterfly species, limited
information currently exists about population-level impacts. Actual
impacts to the Florida leafwing and Bartram's scrub-hairstreak from
mosquito control are unknown at this time; however, additional research
is under way to quantify risk.
In general Long Pine Key in ENP does not appear to be regularly
impacted by mosquito control practices, except for the use of
adulticides (e.g., Sumithrin (Anvil)) in Park residential areas and
campgrounds. Housing areas, maintenance areas, outside work areas for
park maintenance staff and contractors, and areas near buildings have
been sprayed in the past (Perry 2007, pers. comm.). Spraying occurred
within ENP following hurricanes in 2005 (Perry 2008, pers. comm.).
Subsequently, however, no spraying has been conducted in or near Long
Pine Key. Populations of these butterflies occurring adjacent to and
outside ENP in suitable and potential habitat within Miami-Dade County
are also vulnerable to the lethal and sublethal effects of adulticide
applications. However, mosquito control pesticide use within Miami-Dade
County pine rockland areas is limited (approximately 2 to 4 times per
year, and only within a portion of proposed critical habitat) (Vasquez
2013, pers. comm.)
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 both butterflies.
[[Page 47241]]
Cumulative Effects From Factors A Through E
The limited distributions and small population sizes of the Florida
leafwing and Bartram's scrub-hairstreak make them extremely susceptible
to habitat loss, degradation, and modification and other anthropogenic
threats. Mechanisms leading to the decline of the Florida leafwing and
Bartram's scrub-hairstreak, as discussed above, range from local (e.g.,
a lack of adequate fire management, fragmentation, poaching), to
regional (e.g., development, pesticides), to global influences (e.g.,
climate change, sea level rise). The synergistic (interaction of two or
more components) effects of threats (such as hurricane effects on a
species with a limited distribution consisting of just a few small
populations) make it difficult to predict population viability. While
these stressors may act in isolation, it is more probable that many
stressors are acting simultaneously (or in combination) on Florida
leafwing and Bartram's scrub-hairstreak populations.
Summary of Biological Status and Threats
Florida Leafwing
The Florida leafwing has been extirpated (no longer in existence)
from nearly 96 percent of its historical range; the only known extant
population occurs within ENP in Miami-Dade County. Threats of habitat
loss and fragmentation, including climatic change (Factor A), poaching
(Factor B), parasitism and predation (Factor C), and small population
size, restricted range, and influence of chemical pesticides used for
mosquito control (Factor E), still exist for the only remaining
population. Because there is only one small extant population of this
butterfly, and limited law enforcement, collection has and continues to
be a significant threat to this butterfly. Existing regulatory
mechanisms (Factor D) are inadequate to reduce these threats. The
leafwing may be impacted when pine rocklands are converted to other
uses or when lack of fire causes the conversion to habitats that are
unsuitable for this butterfly. Because the remaining population is
isolated and the butterfly has a limited ability to recolonize
historically occupied habitats that are now highly fragmented, it is
vulnerable to natural or human-caused changes in its habitats. As a
result, impacts from increasing threats, singly or in combination, are
likely to result in the extinction of the butterfly as there is no
redundancy of populations.
Bartram's Scrub-Hairstreak
The Bartram's scrub-hairstreak has been extirpated from nearly 93
percent of its historical range; only five isolated populations remain
on Big Pine Key in Monroe County, Long Pine Key in ENP, and relict pine
rocklands adjacent to the Park in Miami-Dade County. All five of these
populations are, in part, on protected lands. Threats of habitat loss
and fragmentation from lack of fire (Factor A), poaching (Factor B),
disease and predation (Factor C), and small population size, restricted
range, and influence of chemical pesticides used for mosquito control
(Factor E) still exist for the remaining populations. Because there are
only five small populations of the hairstreak, and limited law
enforcement, collection has and continues to be a significant threat to
this butterfly. Existing regulatory mechanisms (Factor D) are
inadequate to protect this butterfly from poaching. Because populations
are isolated and the butterfly has a limited ability to recolonize
historically occupied habitats that are now highly fragmented, it is
vulnerable to natural or human-caused changes in its habitats. The
remaining populations become less resilient and are not capable of
recovering from the threats. As a result, impacts from increasing
threats, singly or in combination, are likely to result in the
extinction of the hairstreak.
Both Species
Habitat loss, fragmentation, and degradation, and associated
pressures from increased human population are major threats; these
threats are expected to continue, placing these butterflies at greater
risk. Although efforts are being made to conserve natural areas and
apply prescribed burns, the long-term effects of large-scale and wide-
ranging habitat modification, destruction, and curtailment will last
into the future. Based on our analysis of the best available
information, there is no evidence to suggest that vulnerability to
collection and risks associated with scientific or conservation efforts
will change and, instead, are likely to continue into the future. At
this time, we consider predation, parasitism, and disease to be threats
to both butterflies due to their current tenuous statuses. We have no
information to suggest that vulnerability to these threats will change
in the future. Based on our analysis of the best available information,
we find that existing regulatory mechanisms, due to their inherent
limitations and constraints, are inadequate to address threats to these
butterflies throughout their ranges. We have no information to indicate
that poaching, inconsistent fires, pesticide use, or habitat loss will
be ameliorated in the future by enforcement of existing regulatory
mechanisms.
Therefore, we find it reasonably likely that the effects on the
Florida leafwing and Bartram's scrub-hairstreak will continue at
current levels or potentially increase in the future. Effects of small
population size, isolation, and loss of genetic diversity are likely
significant threats as well as natural changes to habitat and
anthropogenic factors (e.g., pesticides, fire, processes affected by
climate change). Collectively, these threats have impacted the
butterflies in the past, are impacting these butterflies now, and will
continue to impact these butterflies in the future.
Determinations
We have carefully assessed the best scientific and commercial
information available regarding the past, present, and future threats
to the Florida leafwing and Bartram's scrub-hairstreak butterflies. As
described in detail above, both butterflies are currently at risk
throughout all of their respective ranges due to the immediacy,
severity, and scope of threats from habitat destruction and
fragmentation, including climatic change and lack of adequate fire
management (Factor A); poaching (Factor B); parasitism and predation
(Factor C); the inadequacy of existing regulatory mechanisms, including
limited enforcement (Factor D); and small population size, restricted
range, and influence of chemical pesticides used for mosquito control
(Factor E). These stressors have had profound adverse effects on
Florida leafwing and Bartram's scrub-hairstreak populations and the
pine rockland habitat. As a result, impacts from increasing threats,
singly or in combination, are likely to result in the extinction of
these butterflies.
The Act defines an endangered species as any species that is ``in
danger of extinction throughout all or a significant portion of its
range'' and a threatened species as any species ``that is likely to
become endangered throughout all or a significant portion of its range
within the foreseeable future.'' We find that the Florida leafwing and
Bartram's scrub-hairstreak butterflies are presently in danger of
extinction throughout their entire ranges based on the severity and
immediacy of threats currently impacting these subspecies. Their
overall ranges have been significantly reduced; the remaining habitats
and populations are threatened by a variety of factors acting in
combination to reduce the overall
[[Page 47242]]
viability of these subspecies. The risk of extinction is high because
the remaining populations are small and isolated and the potential for
recolonization is limited. Therefore, on the basis of the best
available scientific and commercial data available, we have determined
that the Florida leafwing and Bartram's scrub-hairstreak butterflies
meet the definition of endangered in accordance with sections 3(6) and
4(a)(1) of the Act.
Under the Act and our implementing regulations, a species may
warrant listing if it is endangered or threatened throughout all or a
significant portion of its range. The threats to the survival of these
species occur throughout the species' ranges and are not restricted to
any particular significant portion of those ranges. Accordingly, our
assessment and proposed determination applies to both the species
throughout their entire ranges.
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 and preparation of a draft and final
recovery plan. The recovery outline guides the immediate implementation
of urgent recovery actions and describes the process to be used to
develop a recovery plan. Revisions of the plan may be done to address
continuing or new threats to the species, as new substantive
information becomes available. The recovery plan identifies site-
specific management actions that set a trigger for review of the five
factors that control whether a species remains endangered or may be
reclassified to threatened or delisted, and methods for monitoring
recovery 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 (comprising
species experts, Federal and State agencies, nongovernmental
organizations, and stakeholders) are often established to develop
recovery plans. When completed, the recovery outline, 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 broad 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. To achieve recovery of these species requires
cooperative conservation efforts on private, State, and Tribal lands.
Following publication of this final listing rule, 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.
In addition, under section 6 of the Act, the State of Florida would be
eligible for Federal funds to implement management actions that promote
the protection and recovery of Florida leafwing and Bartram's scrub-
hairstreak butterflies. 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 either or both of these butterflies. Additionally,
we invite you to submit any new information on these butterflies
whenever it becomes available and any information you may have for
recovery planning purposes (see FOR FURTHER INFORMATION CONTACT).
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 designated. Regulations implementing this interagency
cooperation provision of the Act are codified at 50 CFR part 402. When
a species is listed, 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 the species or
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 consultation with the Service.
Federal agency actions within these butterflies' habitat that may
require consultation as described in the preceding paragraph include
but are not limited to, management and any other landscape-altering
activities on Federal lands administered by the Department of Defense,
National Park Service, and U.S. Fish and Wildlife Service; construction
and maintenance of roads or highways by the Federal Highway
Administration; flood insurance and disaster relief efforts conducted
by the Federal Emergency Management Agency; and pesticide treatments
required by the U.S. Department of Agriculture in the event of
emergency pest outbreak.
The Act and its implementing regulations set forth a series of
general prohibitions and exceptions that apply to all endangered
wildlife. The prohibitions of section 9(a)(2) of the Act, codified at
50 CFR 17.21, make it illegal for any person subject to the
jurisdiction of the United States to take (which includes harass, harm,
pursue, hunt, shoot, wound, kill, trap, capture, or collect; or to
attempt any of these) endangered wildlife within the United States or
on the high seas. In addition, it is unlawful to import; export;
deliver, receive, carry, transport, or ship in interstate commerce in
the course of commercial activity; or sell or offer for sale in
interstate or foreign commerce any listed species. It is also illegal
to possess, sell, deliver, carry, transport, or ship any such wildlife
that has been taken illegally. Certain exceptions apply to agents of
the Service, the National Marine Fisheries Service, other Federal land
management agencies, and State conservation agencies.
[[Page 47243]]
We may issue permits to carry out otherwise prohibited activities
involving endangered wildlife under certain circumstances. Regulations
governing permits are codified at 50 CFR 17.22. With regard to
endangered wildlife, a permit must be issued for the following
purposes: For scientific purposes, to enhance the propagation or
survival of the species, and for incidental take in connection with
otherwise lawful activities. There are also certain statutory
exemptions from the prohibitions, which are found in sections 9 and 10
of the Act.
Our policy, as published in the Federal Register on July 1, 1994
(59 FR 34272), is 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. Based on the best
available information, the following activities could potentially
result in a violation of section 9 of the Act; this list is not
comprehensive:
(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
the Florida leafwing or Bartram's scrub-hairstreak butterflies
(research activities where the Florida leafwing or Bartram's scrub-
hairstreak are handled, captured (e.g., netted, trapped), marked, or
collected will require authorization pursuant to the Act).
(2) Incidental take of the Florida leafwing or Bartram's scrub-
hairstreak without authorization pursuant to section 7 or section
10(a)(1)(B) of the Act.
(3) Sale or purchase of specimens of these taxa, except for
properly documented antique specimens at least 100 years old, as
defined by section 10(h)(1) of the Act.
(4) Unauthorized destruction or alteration of the Florida leafwing
or Bartram's scrub-hairstreak habitat (including unauthorized grading,
leveling, plowing, mowing, burning, herbicide spraying, or pesticide
application) in ways that kill or injure individuals by significantly
impairing these butterflies' essential breeding, foraging, sheltering,
or other essential life functions.
(5) Unauthorized use of pesticides or herbicides resulting in take
of the Florida leafwing or Bartram's scrub-hairstreak butterflies.
(6) Unauthorized release of biological control agents that attack
any life stages of these species.
(7) Unauthorized removal or destruction of pineland croton, the
hostplant utilized by the Florida leafwing or Bartram's scrub-
hairstreak butterflies, within areas used by the butterflies that
result in harm to the butterflies.
(8) Release of nonnative species into occupied Florida leafwing and
Bartram's scrub-hairstreak habitat that may displace the butterflies or
their native host plants.
Questions regarding whether specific activities would constitute a
violation of section 9 of the Act should be directed to the Field
Supervisor of the Service's South Florida Ecological Services Office
(see FOR FURTHER INFORMATION CONTACT).
Required Determinations
National Environmental Policy Act (NEPA; 42 U.S.C. 4321 et seq.)
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the NEPA, need not
be prepared in connection with listing a species as an endangered or
threatened species under the Endangered Species Act. We published a
notice outlining our reasons for this determination in the Federal
Register on October 25, 1983 (48 FR 49244).
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994
(Government-to-Government Relations with Native American Tribal
Governments; 59 FR 22951), Executive Order 13175 (Consultation and
Coordination with Indian Tribal Governments), and the Department of the
Interior's manual at 512 DM 2, we readily acknowledge our
responsibility to communicate meaningfully with recognized Federal
Tribes on a government-to-government basis. In accordance with
Secretarial Order 3206 of June 5, 1997 (American Indian Tribal Rights,
Federal-Tribal Trust Responsibilities, and the Endangered Species Act),
we readily acknowledge our responsibilities to work directly with
tribes in developing programs for healthy ecosystems, to acknowledge
that tribal lands are not subject to the same controls as Federal
public lands, to remain sensitive to Indian culture, and to make
information available to tribes. Neither species occurs on any tribal
lands or lands under tribal jurisdiction.
References Cited
A complete list of references cited in this rulemaking is available
on the Internet at http://www.regulations.gov and upon request from the
South Florida Ecological Services Field Office (see FOR FURTHER
INFORMATION CONTACT).
Authors
The primary authors of this proposed rule are the staff members of
the South Florida Ecological Services Field Office).
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; 1531-1544; 4201-4245; unless
otherwise noted.
0
2. Amend Sec. 17.11(h) by adding entries for ``Butterfly, Bartram's
scrub-hairstreak'' and ``Butterfly, Florida leafwing'' to the List of
Endangered and Threatened Wildlife in alphabetical order under Insects
to read as set forth below:
Sec. 17.11 Endangered and threatened wildlife.
* * * * *
(h) * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Species Vertebrate
--------------------------------------------------- population
where Critical Special
Historical range endangered Status Family When listed habitat rules
Common name Scientific name or
threatened
--------------------------------------------------------------------------------------------------------------------------------------------------------
* * * * * * *
Insects ................. ................. ........... .......... ................. ........... ........... ...........
[[Page 47244]]
* * * * * * *
Butterfly, Bartram's scrub- Strymon acis U.S.A. (FL)...... NA E Lycaenidae....... 843 17.95(i) NA
hairstreak. bartrami.
* * * * * * *
Butterfly, Florida leafwing.... Anaea troglodyta U.S.A. (FL)...... NA E Nymphalidae...... 843 17.95(i) NA
floridalis.
* * * * * * *
--------------------------------------------------------------------------------------------------------------------------------------------------------
Dated: July 22, 2014.
Stephen Guertin,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2014-18614 Filed 8-11-14; 8:45 am]
BILLING CODE 4310-55-P