[Federal Register Volume 76, Number 45 (Tuesday, March 8, 2011)]
[Proposed Rules]
[Pages 12667-12683]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2011-4884]


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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R8-ES-2010-0028; MO 92210-0-0008]


Endangered and Threatened Wildlife and Plants; 12-Month Finding 
on a Petition To List the Mt. Charleston Blue Butterfly as Endangered 
or Threatened

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 12-month petition finding.

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SUMMARY: We, the Fish and Wildlife Service (Service), announce a 12-
month finding on a petition to list the Mt. Charleston blue butterfly 
(Plebejus shasta charlestonensis) (formerly in genus Icaricia) as 
endangered or threatened under the Endangered Species Act of 1973, as 
amended. After review of all available scientific and commercial 
information, we find that listing the Mt. Charleston blue butterfly is 
warranted. Currently, however, listing of the Mt. Charleston blue is 
precluded by higher priority actions to amend the Lists of Endangered 
and Threatened Wildlife and Plants. Upon publication of this 12-month 
petition finding, we will add the Mt. Charleston blue butterfly to our 
candidate species list. If an emergency situation develops with this 
subspecies that warrants an emergency listing, we will act immediately 
to provide additional protection. We will develop a proposed rule to 
list this subspecies as our priorities allow. We will make any 
determination on critical habitat during development of the proposed 
listing rule.

DATES: The finding announced in the document was made on March 8, 2011.

ADDRESSES: This finding is available on the Internet at http://www.regulations.gov at Docket Number FWS-R8-ES-2010-0028 and at http://www.fws.gov/nevada. Supporting documentation we used in preparing this 
finding is available for public inspection, by appointment, during 
normal business hours at the U.S. Fish and Wildlife Service, Nevada 
Fish and Wildlife Office, 4701 North Torrey Pines Drive, Las Vegas, NV 
89130. Please submit any new information, materials, comments, or 
questions concerning this finding to the above street address.

FOR FURTHER INFORMATION CONTACT: Jill Ralston, Deputy Field Supervisor, 
Nevada Fish and Wildlife Office (see ADDRESSES); by telephone at (702) 
515-5230; or by facsimile at (702) 515-5231. Persons who use a 
telecommunications device for the deaf (TDD) may call the Federal 
Information Relay Service (FIRS) at (800) 877-8339.

SUPPLEMENTARY INFORMATION:

Background

    Section 4(b)(3)(B) of the Endangered Species Act of 1973, as 
amended (Act) (16 U.S.C. 1531 et seq.), requires that, for any petition 
containing substantial scientific or commercial information indicating 
that listing the species may be warranted, we make a finding within 12 
months of the date of the receipt of the petition. In this finding, we 
determine that the petitioned action is: (a) Not warranted, (b) 
warranted, or (c) warranted, but the immediate proposal of a regulation 
implementing the petitioned action is precluded by other pending 
proposals to determine whether species are endangered or threatened, 
and expeditious progress is being made to add or remove qualified 
species from the Federal Lists of Endangered and Threatened Wildlife 
and Plants. Section 4(b)(3)(C) of the Act requires that we treat a 
petition for which the requested action is found to be warranted but 
precluded as though resubmitted on the date of such finding, that is, 
requiring a subsequent finding to be made within 12 months. We must 
publish these 12-month findings in the Federal Register.

Previous Federal Actions

    On October 20, 2005, we received a petition dated October 20, 2005, 
from The Urban Wildlands Group, Inc., requesting that we emergency list 
the Mt. Charleston blue butterfly (Mt. Charleston blue) (Plebejus 
shasta charlestonensis) (formerly in genus Icaricia) as an endangered 
or threatened species. In a letter dated April 20, 2006, we responded 
to the petitioner that our initial review did not indicate that an 
emergency situation existed, but that if conditions changed an 
emergency rule could be developed. On May 30, 2007, we published a 90-
day petition finding (72 FR 29933) in which we concluded that the 
petition provided substantial information indicating that listing of 
the Mt. Charleston blue may be warranted, and we initiated a status 
review. On February 17, 2010, the Center for Biological Diversity filed 
a complaint in United States District Court, Eastern District of 
California, indicating that the Service failed to take required actions 
on seven separate petitions for listed species found throughout the 
western United States including the Mt. Charleston blue. On April 26, 
2010, CBD amended its complaint in Center for Biological Diversity v. 
Salazar, U.S. Fish and Wildlife Service, Case No.: 1:10-cv-230-PLF 
(D.D.C.), adding an allegation that the Service failed to issue its 12-
month petition finding on the Mount Charleston blue butterfly within 
the mandatory statutory timeframe. This notice constitutes the 12-month 
finding on the October 20, 2005, petition to list the Mt. Charleston 
blue as endangered or threatened.

Species Information

Taxonomy
    The Mt. Charleston blue is a distinctive subspecies of the wider 
ranging Shasta blue butterfly (Plebejus shasta), which is a member of 
the Lycaenidae family. Pelham (2008, pp. 25-26) recognized seven 
subspecies of Shasta blue: P. s. shasta, P. s. calchas, P. s. 
pallidissima, P. s. minnehaha, P. s. charlestonensis, P. s. 
pitkinensis, and P. s. platazul. The Mt. Charleston blue is known only 
from the high elevations of the Spring Mountains, located approximately 
25 miles (mi) (40 kilometers (km)) west of Las Vegas in Clark County, 
Nevada (Austin 1980, p. 20; Scott 1986, p. 410). The first mention of 
the Mt. Charleston blue as a unique taxon was in 1928 by Garth, who 
recognized it as distinct from the species Shasta blue (Austin 1980, p. 
20). Howe, in 1975 (as cited in Austin 1980, p. 20), described 
specimens from the Spring Mountains as P. s. shasta form comstocki. 
However, in 1976, Ferris (as cited in Austin 1980, p. 20) placed the 
Mt. Charleston blue with the wider ranging Minnehaha blue subspecies. 
Finally, Austin asserted that Ferris had not included populations from 
the Sierra Nevada in his study, and that in light of the geographic 
isolation and distinctiveness of the Shasta blue population in the 
Spring Mountains and the presence of at least three other well-defined 
races of butterflies endemic to the area, it was appropriate to name 
this population as the individual subspecies Mt. Charleston blue (P. s. 
charlestonensis) (Austin 1980, p. 20). Our use of the genus name 
Plebejus, rather than the synonym Icaricia, reflects recent treatments 
of butterfly taxonomy (Opler and Warren 2003, p. 30; Pelham 2008, p. 
265).

[[Page 12668]]

    The wingspan of Shasta blue species is 0.75 to 1 inch (in) (19 to 
26 millimeters (mm)) (Opler 1999, p. 251). Males and females of Shasta 
blue are dimorphic. The upperside of males is dark to dull iridescent 
blue, and females are brown with a blue overlay. The species has a 
discal black spot on the forewing and a row of submarginal black spots 
on the hindwing. The underside is gray, with a pattern of black spots, 
brown blotches, and pale wing veins to give it a mottled appearance. 
The underside of the hindwing has an inconspicuous band of submarginal 
metallic spots (Opler 1999, p. 251). Based on morphology, the Mt. 
Charleston blue appears to be most closely related to the Great Basin 
populations of Minnehaha blue (Austin 1980, p. 23) and can be 
distinguished from other Shasta blue subspecies by the presence of 
sharper and blacker post medial spots on the underside of the hindwing 
(Scott 1986, p. 410).
Biology
    The Mt. Charleston blue is generally thought to diapause (a period 
of suspended growth or development similar to hibernation) at the base 
of its larval host plant, Torrey's milkvetch (Astragalus calycosus var. 
calycosus), or in the surrounding substrate. The pupae of some 
butterfly species are known to persist in diapause up to 5 to 7 years 
(Scott 1986, p. 28). The number of years the Mt. Charleston blue can 
remain in diapause is unknown. Local experts have speculated that the 
Mt. Charleston blue may only be able to diapause for one season. 
However, in response to unfavorable environmental conditions, it is 
hypothesized that a prolonged diapause period may be possible (Scott 
1986, pp. 26-30; Murphy 2006, p. 1; Datasmiths 2007, p. 6; Boyd and 
Murphy 2008, p. 22).
    The typical flight and breeding period for the butterfly is early 
July to mid-August with a peak in late July, although the subspecies 
has been observed as early as mid-June and as late as mid-September 
(Austin 1980, p. 22; Boyd and Austin 1999, p. 17; Forest Service 2006a, 
p. 9). As with most butterflies, the Mt. Charleston blue typically 
flies during sunny conditions, which are particularly important for 
this subspecies given the cooler air temperatures at high elevations 
(Weiss et al. 1997, p. 31). Excessive winds also deter flight of most 
butterflies, although Weiss et al. (1997, p. 31) speculate this may not 
be a significant factor for the Mt. Charleston blue given its low-to-
the-ground flight pattern.
    Like all butterfly species, both the phenology (timing) and number 
of Mt. Charleston blue individuals that emerge and fly to reproduce 
during a particular year are reliant on the combination of many 
environmental factors that may constitute a successful (``favorable'') 
or unsuccessful (``poor'') year for the subspecies. Other than 
observations by surveyors, little information is known regarding these 
aspects of the subspecies' biology, since the key determinants for the 
interactions among the butterfly's flight and breeding period, larval 
host plant, and environmental conditions have not been specifically 
studied. Observations indicate that above or below average 
precipitation, coupled with above or below average temperatures, 
influence the phenology of this subspecies (Weiss et al. 1997, pp. 2-3 
and 32; Boyd and Austin 1999, p. 8) and are likely responsible for the 
fluctuation in population numbers from year to year (Weiss et al. 1997, 
pp. 2-3 and 31-32).
    Most butterfly populations exist as regional metapopulations 
(groups of spatially separated populations that may function as single 
populations due to occasional interbreeding) (Murphy et al. 1990, p. 
44). Boyd and Austin (1999, pp. 17 and 53) indicate this is true of the 
Mt. Charleston blue. Small habitat patches tend to support smaller 
butterfly populations that are frequently extirpated by events that are 
part of normal variation (Murphy et al. 1990, p. 44). Boyd and Austin 
(1999, p. 17) suggest smaller colonies of the Mt. Charleston blue may 
be ephemeral in the long term, with the larger colonies of the 
subspecies more likely than smaller populations to persist in ``poor'' 
years, when environmental conditions do not support the emergence, 
flight, and reproduction of individuals. The ability of the Mt. 
Charleston blue to move between habitat patches has not been studied; 
however, field observations suggest the subspecies has low vagility 
(capacity or tendency of a species to move about or disperse in a given 
environment), on the order of 10 to 100 meters (m) (33 to 330 feet 
(ft)) (Weiss et al. 1995, p. 9), and nearly sedentary behavior 
(Datasmiths 2007, p. 21; Boyd and Murphy 2008, pp. 3 and 9). 
Furthermore, dispersal of lycaenid butterflies, in general, is limited 
and on the order of hundreds of meters (Cushman and Murphy 1993, p. 
40). Based on this information, the likelihood of long-distance 
dispersal is low for the Mt. Charleston blue.
Habitat
    Weiss et al. (1997, pp. 10-11) describe the natural habitat for the 
Mt. Charleston blue butterfly as relatively flat ridgelines above 2,500 
m (8,200 ft), but isolated individuals have been observed as low as 
2,000 m (6,600 ft). Boyd and Murphy (2008, p. 19) indicate that areas 
occupied by the subspecies feature exposed substrates with limited or 
no canopy cover or shading, and are on flats or mild slopes with 
moderate aspects. Like most butterfly species, the Mt. Charleston blue 
is dependent on plants both during larval development (larval host 
plants) and the adult butterfly flight period (nectar plants). The Mt. 
Charleston blue requires areas that support Torrey's milkvetch, the 
only known larval host plant for the subspecies (Weiss et al. 1994, p. 
3; Weiss et al. 1997, p. 10; Datasmiths 2007, p. 21), as well as 
primary nectar plants. Torrey's milkvetch and Clokey fleabane (Erigeron 
clokeyi) are the primary nectar plants for the subspecies; however, 
butterflies have also been observed nectaring on Lemmon's bitterweed 
(Hymenoxys lemmonii) and Aster sp. (Weiss et al. 1994, p. 3; Boyd 2005, 
p. 1; Boyd and Murphy 2008, p. 9).
    The best available habitat information relates mostly to the Mt. 
Charleston blue's larval host plant, with little to no information 
available characterizing the butterfly's interactions with its known 
nectar plants or other elements of its habitat; thus, the habitat 
information discussed in this document centers on Torrey's milkvetch. 
Studies are currently underway to better understand the habitat 
requirements and preferences of the Mt. Charleston blue (Thompson and 
Garrett 2010, p. 2; Pinyon 2010a, p. 1). Torrey's milkvetch is a small, 
low-growing, perennial herb that grows in open areas between 5,000 to 
10,800 ft (1,520 to 3,290 m) in subalpine, bristlecone, and mixed-
conifer vegetation communities of the Spring Mountains. Within the 
alpine and subalpine range of the Mt. Charleston blue, Weiss et al. 
(1997, p. 10) observed the highest densities of Torrey's milkvetch in 
exposed areas and within canopy openings and lower densities in 
forested areas.
    Weiss et al. (1997, p. 31) describe favorable habitat for the Mt. 
Charleston blue as having high densities (more than 10 plants per 
square meter) of Torrey's milkvetch. Weiss et al. (1995, p. 5) and 
Datasmiths (2007, p. 21) suggest that in some areas butterfly habitat 
may be dependent on old or infrequent disturbances that create open 
areas. Vegetation cover within disturbed patches naturally becomes 
higher over time through natural succession, gradually becoming less 
favorable to the butterfly. Therefore, we conclude that open areas with 
relatively little grass cover and visible mineral soil and high

[[Page 12669]]

densities of host plants support the highest densities of butterflies 
(Boyd 2005, p. 1; Service 2006a, p. 1). During 1995, an especially high 
population year, Mt. Charleston blue were observed in small habitat 
patches and in open forested areas where Torrey's milkvetch was present 
in low densities, on the order of 1 to 5 plants per square meter (Weiss 
et al. 1997, p. 10; Newfields 2006, pp. 10 and C5). Therefore, areas 
with lower densities of the host plant may also be important to the 
subspecies, as these areas may be intermittently occupied or may be 
important for dispersal.
    Fire suppression and other management practices have likely limited 
the formation of new habitat for the Mt. Charleston blue. The U.S. 
Forest Service (USFS) began suppressing fires on the Spring Mountains 
in 1910 (Entrix 2007, p. 111). Throughout the Spring Mountains, fire 
suppression has resulted in higher densities of trees and shrubs (Amell 
2006, pp. 2-3) and a transition to a closed-canopy forest with shade-
tolerant understory species (Entrix 2007, p. 112) that is generally 
less suitable for the Mt. Charleston blue. Boyd and Murphy (2008, pp. 
23 and 25) hypothesized that the loss of presettlement vegetation 
structure over time has caused the Mt. Charleston blue's metapopulation 
dynamics to collapse in Upper Lee Canyon. Similar losses of suitable 
butterfly habitat in woodlands and their negative effect on butterfly 
populations have been documented (Thomas 1984, pp. 337-338). Natural 
landscape processes have been modified in the Spring Mountains. Now, 
the disturbed landscape at the Las Vegas Ski and Snowboard Resort 
(LVSSR) provides important habitat for the Mt. Charleston blue (The 
Urban Wildlands Group, Inc. 2005, p. 2). Periodic maintenance (removal 
of trees and shrubs) of the ski runs has effectively arrested forest 
succession on the ski slopes and serves to maintain conditions 
favorable to the Mt. Charleston blue, and to its host and nectar 
plants. However, the ski runs are not specifically managed to benefit 
habitat for this subspecies and operation activities regularly modify 
Mt. Charleston blue habitat or prevent host plants from reestablishing 
in disturbed areas.
Range and Current Distribution
    Based on current and historical occurrences or locations documented 
in the petition or identified in the State of Nevada Natural Heritage 
Program database (The Urban Wildlands Group, Inc. 2005, pp. 1-3; 
Service 2006b, pp. 2-4), the geographic range of the Mt. Charleston 
blue is primarily on the east side of the Spring Mountains, centered on 
lands managed by the USFS in the Spring Mountains National Recreation 
Area of the Humboldt-Toiyabe National Forest within Upper Kyle and Lee 
Canyons, Clark County, Nevada. The majority of the occurrences or 
locations are in the Upper Lee Canyon area, while a few are in Upper 
Kyle Canyon. Table 1 lists the various locations of the Mt. Charleston 
blue that constitute the subspecies' current and historical range.

     Table 1--Locations or Occurrences of the Mt. Charleston Blue Butterfly Since 1928 and the Status of the
                                           Butterfly at the Locations
----------------------------------------------------------------------------------------------------------------
                                       First/last  Most recent
            Location name                 time        survey             Status             Primary references
                                        observed     year(s)
----------------------------------------------------------------------------------------------------------------
1. South Loop Trail, Upper Kyle         1995/2010  2007, 2008,  Known occupied, adults   NNHP 2007; Weiss et al.
 Canyon.                                                  2010   consistently observed.   1997; Kingsley 2007;
                                                                                          Boyd 2006; Datasmiths
                                                                                          2007; SWCA 2008,
                                                                                          Pinyon 2010a, Thompson
                                                                                          and Garrett 2010.
2. LVSSR, Upper Lee Canyon..........    1963/2010  2007, 2008,  Known occupied, adults   NNHP 2007; Weiss et al.
                                                          2010   consistently observed.   1994; Weiss et al.
                                                                                          1997; Boyd and Austin
                                                                                          2002; Boyd 2006;
                                                                                          Newfields 2006;
                                                                                          Datasmiths 2007; Boyd
                                                                                          and Murphy 2008,
                                                                                          Thompson and Garrett
                                                                                          2010.
3. Foxtail Upper Lee Canyon.........    1995/1998   2006, 2007  Presumed occupied,       NNHP 2007; Boyd and
                                                                 adults intermittently    Austin 1999; Boyd
                                                                 observed.                2006; Datasmiths 2007.
4. Youth Camp, Upper Lee Canyon.....    1995/1995   2006, 2007  Presumed occupied,       Weiss et al. 1997; Boyd
                                                                 adults intermittently    2006; Datasmiths 2007.
                                                                 observed.
5. Gary Abbott, Upper Lee Canyon....    1995/1995   2006, 2007  Presumed occupied,       NNHP 2007; Weiss et al.
                                                                 adults intermittently    1997; Boyd 2006;
                                                                 observed.                Datasmiths 2007.
6. Lower LVSSR Parking, Upper Lee       1995/2002   2007, 2008  Presumed occupied,       Urban Wildlands Group,
 Canyon.                                                         adults intermittently    Inc. 2005; Weiss et
                                                                 observed.                al. 1997; Boyd 2006;
                                                                                          Datasmiths 2007; Boyd
                                                                                          and Murphy 2008.
7. Mummy Spring, Upper Kyle Canyon      1995/1995         2006  Presumed occupied,       NNHP 2007; Weiss et al.
 \1\.                                                            adults intermittently    1997; Boyd 2006.
                                                                 observed.
8. Lee Meadows, Upper Lee Canyon....    1965/1995   2006, 2007  Presumed occupied,       NNHP 2007; Weiss et al.
                                                                 adults intermittently    1997; Boyd 2006;
                                                                 observed.                Datasmiths 2007.
9. Bonanza Trail....................    1995/1995   2006, 2007  Presumed occupied......  Weiss et al. 1997; Boyd
                                                                                          2006; Kingsley 2007.
10. Upper Lee Canyon holotype \1\...    1963/1976   2006, 2007  Presumed extirpated....  NNHP 2007; Weiss et al.
                                                                                          1997; Boyd 2006;
                                                                                          Datasmiths 2007.
11. Cathedral Rock, Kyle Canyon.....    1972/1972         2007  Presumed extirpated....  NNHP 2007; Weiss et al.
                                                                                          1997; Datasmiths 2007.
12. Upper Kyle Canyon Ski Area \1\..    1965/1972         1995  Presumed extirpated....  NNHP 2007; Weiss et al.
                                                                                          1997.
13. Old Town, Kyle Canyon \2\.......        1970s         1995  Presumed extirpated....  The Urban Wildlands
                                                                                          Group, Inc. 2005.
14. Deer Creek, Kyle Canyon.........         1950      unknown  Presumed extirpated....  NNHP 2007.
15. Willow Creek....................         1928      unknown  Presumed extirpated....  NNHP 2007; Weiss et al.
                                                                                          1997, Thompson and
                                                                                          Garrett 2010.
----------------------------------------------------------------------------------------------------------------
\1\ Location is not mentioned in the petition.
\2\ Location is not identified in the Nevada Natural Heritage Program database.


[[Page 12670]]

    We presume that the Mt. Charleston blue is extirpated from a 
location when it has not been recorded at that location through formal 
surveys or informal observation for more than 20 years. We selected a 
20-year time period because it would likely allow for local extirpation 
and recolonization events (metapopulation dynamics) to occur and would 
be enough time for succession or other vegetation shifts to render the 
habitat unsuitable (see discussion in ``Biology'' and ``Habitat'' 
sections above). Using this criterion, the Mt. Charleston blue is 
considered to be ``presumed extirpated'' from 6 of the 14 known 
locations (Locations 9-14 in Table 1) (The Urban Wildlands Group, Inc. 
2005, pp. 1-3; Service 2006b, pp. 8-9). Of the remaining eight 
locations, six locations or occurrences are ``presumed occupied'' by 
the subspecies (Locations 3-8 in Table 1) (The Urban Wildlands Group, 
Inc. 2005, pp. 1-3; Service 2006b, pp. 7-8).
    This category is defined as a location within the current known 
range of the subspecies where adults have been intermittently observed 
and there is a potential for diapausing larvae to be present. The 
butterfly likely exhibits metapopulation dynamics at these locations, 
where the subspecies is subject to local extirpation, with new 
individuals emigrating from nearby ``known occupied'' habitat, 
typically during years when environmental conditions are more favorable 
to emergence from diapause and the successful reproduction of 
individuals (see discussion in ``Habitat'' section above). At some of 
these presumed occupied locations (Locations 4, 5, 7, 8 and 9 in Table 
1), the Mt. Charleston blue has not been recorded through formal 
surveys or informal observation since 1995 by Weiss et al. (1997, pp. 
1-87). Currently, we consider the occurrence at Mummy Spring as 
presumed occupied; however, this location is not near known occupied 
habitat and may be extirpated.
    We consider the remaining two Mt. Charleston blue locations or 
occurrences to be ``known occupied'' (Locations 1 and 2 in Table 1). 
The South Loop Trail location in Upper Kyle Canyon (Location 1 in Table 
1) is considered known occupied because: (1) The butterfly was observed 
on the site in 1995, 2002, 2007, and 2010 (Service 2007, pp. 1-2; 
Kingsley 2007, p. 5; Pinyon 2010, pp. 1-2; Thompson and Garrett 2010, 
p. 5); and (2) the high quality of the habitat is in accordance with 
host plant densities of 10 plants per square meter as described in 
Weiss et al. (1997, p. 31; Kingsley 2007, pp. 5 and 10), and is in an 
area of relatively large size (18.7 acres (ac) (7.6 hectares (ha)) 
(SWCA 2008, pp. 2 and 5). The South Loop Trail area appears to be the 
most important remaining population area for the Mt. Charleston blue 
(Boyd and Murphy 2008, p. 21). The South Loop Trail runs along the 
ridgeline between Griffith Peak and Charleston Peak and is located 
within the Mt. Charleston Wilderness. This area was field mapped using 
a global positioning system unit and included the larval host plant, 
Torrey's milkvetch, as well as occurrences of two known nectar plants, 
Lemmon's bitterweed and Clokey fleabane (SWCA 2008, pp. 2 and 5). 
Adjacent to this ``known occupied'' habitat of 18.7 ac (7.6 ha) occurs 
approximately 40 ac (17 ha) of additional habitat containing Lemmon's 
bitterweed and Clokey fleabane, as well as a smaller patch of Torrey's 
milkvetch (1.6 ac) (0.65 ha) (SWCA 2008, pp. 2 and 5).
    We consider LVSSR in Upper Lee Canyon (Location 2 in Table 1) to be 
``known occupied'' because: (1) The butterfly was first recorded at 
LVSSR in 1963 (Austin 1980, p. 22) and has been consistently observed 
at LVSSR every year between 1995 and 2006 (with the exception of 1997 
when no surveys were performed, and in recent years when the species 
was not observed) (Service 2007, pp. 1-2) and in 2010 (Thompson and 
Garrett 2010, p. 5); and (2) the ski runs contain two areas of high-
quality butterfly habitat in accordance with host plant densities of 10 
plants per square meter as described in Weiss et al. (1997, p. 31). 
These areas are LVSSR 1(2.4 ac (0.97 ha)) and LVSSR 2 
(1.3 ac (0.53 ha)), which have been mapped using a global positioning 
system unit and field verified. Thus, across its current range, the Mt. 
Charleston blue is known to persistently occupy less than 22.4 ac (9.1 
ha) of habitat.
Status and Trends
    The Mt. Charleston blue has been characterized as particularly 
rare, but common in some years (Boyd and Austin 1999, p. 17; The Urban 
Wildlands Group, Inc. 2005, p. 2). The 1995 season was the last year 
the butterfly was present in high numbers. Variations in precipitation 
and temperature that affect both the Mt. Charleston blue and its larval 
host plant are likely responsible for the fluctuation in population 
numbers from year to year (Weiss et al. 1997, pp. 2-3 and 31-32). The 
total population of the Mt. Charleston blue is unknown. We do not have 
population estimates for the butterfly or specific information showing 
a change in numbers; however, it appears the population has declined 
since the last high-population year in 1995 (Murphy 2006, pp. 1-2).
    Recent survey information indicates the Mt. Charleston blue 
population appears to be extremely low. In 2006, surveys within 
presumed occupied habitat at LVSSR located one individual butterfly 
adjacent to a pond that holds water for snowmaking (Newfields 2006, pp. 
10, 13, and C5). In a later report, the accuracy of this observation 
was questioned and considered inaccurate (Newfields 2008, p. 27). In 
2006, Boyd (2006, pp. 1-2) conducted focused surveys for the subspecies 
at nearly all previously known locations and within potential habitat 
along Griffith Peak, North Loop Trail, Bristlecone Trail, and South 
Bonanza Trail but did not observe the butterfly at any of these 
locations. In 2007, surveys were again conducted in previously known 
locations in Upper Lee Canyon and LVSSR, but no butterflies were 
recorded (Datasmiths 2007, p. 1; Newfields 2008, pp. 21-24). In 2007, 
two Mt. Charleston blue butterflies were sighted on different dates at 
the same location on the South Loop Trail in Upper Kyle Canyon 
(Kingsley 2007, p. 5). In 2008, butterflies were not observed during 
focused surveys of Upper Lee Canyon and the South Loop Trail (Boyd and 
Murphy 2008, pp. 1-3; Boyd 2008, p. 1; SWCA 2008, p. 6), although it is 
possible adult butterflies may have been missed on South Loop Trail 
because the surveys were performed very late in the season. No formal 
surveys were conducted in 2009; however, no individuals were seen 
during the few informal attempts made to observe the species.
    Adults of the Mt. Charleston blue were most recently observed in 
2010 in the South Loop Trail area and LVSSR. From reports of several 
adult surveys in July and August at the South Loop area (Thompson and 
Garrett 2010; Pinyon 2010a, pp. 1-2; Pinyon 2010b), the highest total 
counted among the days this area was surveyed was 17 on July 28 (Pinyon 
2010b). One adult was observed in Lee Canyon at LVSSR on July 23, 2010, 
but no other adults were detected at LVSSR on surveys conducted August 
2, 9, and 18, 2010 (Thompson and Garrett 2010, pp. 4-5). Final reports 
have not been completed for these projects and the results are 
considered preliminary.
    The availability of known larval and nectar plants does not appear 
to be correlated to the recent low population numbers of the butterfly 
as the host plants continue to persist at previously occupied locations 
and throughout the Spring Mountains. The low number of butterflies 
observed during the 2006,

[[Page 12671]]

2007, 2008, and 2010 seasons could be partially attributed to extreme 
weather (e.g., heavy precipitation events and drought). Prior to 2005, 
there were numerous years of drought, followed by a record snow in the 
winter of 2004-2005. In 2006 and 2007, the area experienced dry winters 
and springs and severe thunderstorms during the summers and flight 
periods. Based on the available survey information, the low number of 
sightings in recent years is likely the result of an already small 
population size, exacerbated by unfavorable weather conditions. 
Historical and recent survey information for this subspecies is very 
limited or unavailable in regard to population data. Thus, we focused 
our threats analysis on assessed threats at known occupied and presumed 
occupied locations (summarized in Table 1).

Summary of Information Pertaining to the Five Threat Factors

    Section 4 of the Act (16 U.S.C. 1533) and implementing regulations 
(50 CFR part 424) set forth procedures for adding species to the 
Federal Lists of Endangered and Threatened Wildlife and Plants. Under 
section 4(a)(1) of the Act, a species may be determined to be 
endangered or threatened 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.
    We summarize below information regarding the status of and threats 
to this subspecies in relation to the five factors in section 4(a)(1) 
of the Act. In making our 12-month finding, we considered and evaluated 
all scientific and commercial information in our files, including 
information received in response to our request for information in the 
notice of 90-day petition finding and initiation of status review (72 
FR 29933), and additional scientific information from ongoing species 
surveys as they became available. In response to the information 
request, we received two letters from private organizations that 
provided information and comments on the Mt. Charleston blue.

Factor A: The Present or Threatened Destruction, Modification, or 
Curtailment of the Species' Habitat or Range

Fire Suppression, Succession, and Nonnative Species
    Butterflies have extremely specialized habitat requirements (Thomas 
1984, p. 337). Changes in vegetation structure and composition as a 
result of natural processes are a serious threat to butterfly 
populations because these changes can disrupt specific habitat 
requirements (Thomas 1984, pp. 337-341; Thomas et al. 2001, pp. 1791-
1796). Cushman and Murphy (1993, p. 4) determined 28 at-risk lycaenid 
butterfly species, including the Mt. Charleston blue, to be dependent 
on one or two closely related host plants. Many of these host plants 
are dependent on early successional environments. Butterflies that 
specialize on such plants must track an ephemeral resource base that 
itself depends on unpredictable and perhaps infrequent ecosystem 
disturbances. For such butterfly species, local extinction events are 
both frequent and inevitable (Cushman and Murphy 1993, p. 4). The Mt. 
Charleston blue may, in part, depend on disturbances that open up the 
subalpine canopy and create conditions more favorable to its host 
plant, Torrey's milkvetch, and nectar resources (Weiss et al. 1995, p. 
5; Boyd and Murphy 2008, pp. 22-28) (see Habitat section, above).
    Fire suppression in the Spring Mountains has resulted in long-term 
successional changes including increased forest area and forest 
structure (higher canopy cover, more young trees, and more trees 
intolerant of fire) (Nachlinger and Reese 1996, p. 37; Amell 2006, pp. 
6-9; Boyd and Murphy 2008, pp. 22-28; Denton et al. 2008, p. 21). 
Frequent low-severity fires would have maintained an open forest 
structure characterized by uneven-aged stands of fire-resistant 
ponderosa pine trees (Amell 2006, p. 5) in lower elevations. The lower-
elevation habitats of the Mt. Charleston blue has likely been the most 
affected by fire suppression as indicated by Provencher's 2008 Fire 
Regime Condition Class analysis of the Spring Mountains (p. 18) in 
which higher-elevation biophysical settings departed less from the 
natural range of variability than those at middle elevations.
    Large-diameter ponderosa pine trees with multiple fire scars in 
upper Lee and Kyle Canyons indicate that low-severity fires 
historically burned through mixed-conifer forests within the range of 
the Mt. Charleston blue (Amell 2006, p. 3). Open mixed-conifer forests 
in the Spring Mountains were likely characterized by more abundant and 
diverse understory plant communities compared to current conditions 
(Entrix 2007, pp. 73-78). These successional changes have been 
hypothesized to have contributed to the decline of the Mt. Charleston 
blue because of reduced densities of larval and nectar plants, 
decreased solar radiation, and inhibited butterfly movements that 
subsequently determine colonization or recolonization processes (Weiss 
et al. 1997, p. 26; Boyd and Murphy 2008, pp. 22-28). Boyd and Murphy 
(2008, p. 23) noted that important habitat characteristics required by 
Mt. Charleston blue--Torrey's milkvetch and preferred nectar plants 
occurring together in open sites not shaded by tree canopies--would 
have occurred more frequently across a more open, forested landscape 
compared to the current denser forested landscape. Not only would the 
changes in forest structure and understory plant communities result in 
habitat loss and degradation for the Mt. Charleston blue across a broad 
spatial scale, a habitat matrix dominated by denser forest also may be 
impacting key metapopulation processes by reducing probability of 
recolonization following local population extirpations in remaining 
patches of suitable habitat (Boyd and Murphy 2008, p. 25).
    The introduction of forbs, shrubs, and nonnative grasses can be a 
threat to butterfly populations because these species can compete with, 
and decrease, the quality and abundance of larval host plant and adult 
nectar sources. This has been observed for many butterfly species 
including the Quino checkerspot butterfly (Euphydryas editha quino) (62 
FR 2313; January 16, 1997) and Fender's blue butterfly (Icaricia 
icarioides fenderi) (65 FR 3875; January 25, 2000). Datasmiths (2007, 
p. 21) also suggest suitable habitat patches of Torrey's milkvetch are 
often, but not exclusively, associated with older or infrequent 
disturbance. Weiss et al. (1995, p. 5) note that a colony once existed 
on the Upper Kyle Canyon Ski Area (Location 11 in Table 1), but since 
the ski run was abandoned no butterflies have been collected there 
since 1965. Boyd and Austin (2002, p. 13) observe that the butterfly 
was common at Lee Meadows (Location 8 in Table 1) in the 1960s, but 
became uncommon at the site because of succession and a potential lack 
of disturbance. Using an analysis of host plant density, Weiss et al. 
(1995 p. 5) concluded that Lee Meadows does not have enough host plants 
to support a population over the long term.

[[Page 12672]]

Succession, coupled with the introduction of nonnative species, is also 
believed to be the reason the Mt. Charleston blue is no longer present 
at the old town site in Kyle Canyon (Location 12 in Table 1) and at the 
holotype site in Upper Lee Canyon (Location 9 in Table 1) (Urban 
Wildlands Group, Inc. 2005, p. 3; Boyd and Austin 1999, p. 17).
    Management of nonnative species within butterfly habitat is a 
threat to the butterfly. As mentioned previously (see Habitat section), 
periodic maintenance (removal of trees and shrubs) of the ski runs has 
effectively arrested succession on the ski slopes and maintains 
conditions that can be favorable to the Mt. Charleston blue. However, 
the ski runs are not specifically managed to benefit habitat for this 
subspecies, and operation activities (including seeding of nonnative 
species) regularly modify butterfly habitat or prevent host plants from 
reestablishing in disturbed areas. Weiss et al. (1995, pp. 5-6) suggest 
that the planting of annual grasses and Melilotus for erosion control 
at LVSSR is a threat to Mt. Charleston blue habitat. Titus and Landau 
(2003, p. 1) observed that vegetation on highly and moderately 
disturbed areas of the LVSSR ski runs are floristically very different 
from natural clearings in the adjacent forest that support the 
butterfly. Seeding nonnative species for erosion control was 
discontinued in 2005; however, because of erosion problems during 2006 
and 2007, and the lack of native seed, LVSSR resumed using a nonnative 
seed mix, particularly in the lower portions of the ski runs (not 
adjacent to Mt. Charleston blue habitat) where erosion problems 
persist.
    Based on available information, it appears that in at least four of 
the six locations where the butterfly historically occurred, suitable 
habitat is no longer present due to vegetation changes attributable to 
succession, the introduction of nonnative species, or a combination of 
the two.
Recreation Development Projects
    As previously detailed in the ``Range and Current Distribution'' 
section of this finding, the Mt. Charleston blue is a narrow endemic 
subspecies that is currently known to occupy two locations and presumed 
to occupy six others. This distribution is on lands managed by the USFS 
(including LVSSR, which is operated under a USFS special use permit) in 
the Spring Mountains National Recreation Area within the Humboldt-
Toiyabe National Forest. We analyzed USFS' recreation development 
projects from 2000 to 2007 to determine if habitat impacts resulting 
from completed and pending projects are a threat to the subspecies at 
these locations, as cited in the petition and referenced in the 90-day 
petition finding. In addition to a fuels reduction project, we 
identified seven projects that have removed or impacted butterfly 
habitat in Upper Lee Canyon, where the butterfly is known or presumed 
to be present. We determined that an eighth impact identified in the 
petition and 90-day petition finding, an unsanctioned trail that 
bisects habitat on the South Loop Trail in Upper Kyle Canyon, is not a 
threat to the butterfly (Kingsley 2007, p. 17).
    In general, it is difficult to know the full extent of impacts to 
the Mt. Charleston blue as a result of these projects because butterfly 
habitat was not mapped for the majority of them nor were some project 
areas surveyed prior to implementation. The majority of impacts 
associated with these projects have not been mitigated, and some of the 
impacted areas have not recovered. Given the slow natural rate of 
recovery, the pace of restoration efforts (see Factor D), and the 
potential for recurrent disturbance at many of these sites, we do not 
expect these impacted areas to provide butterfly habitat for many years 
to come, unless noted below. The following is a summary of the 
recreation development projects that have removed or impacted Mt. 
Charleston blue habitat from 2000 to 2010.
    (1) During 2000 or 2001, a series of earthen berms were constructed 
at the top of a ski run at LVSSR. These berms were created by scraping 
topsoil from the ski run in an area known to support high densities of 
Torrey's milkvetch. This activity caused loss and degradation of an 
unknown area of presumed occupied butterfly habitat at LVSSR, Upper Lee 
Canyon (Location 2 in Table 1) (The Urban Wildlands Group, Inc. 2005, 
p. 3; Service 2006a, pp. 1-5). We assume, based on the level of soil 
disturbance, this activity would have also killed any larvae, pupae, or 
eggs present. Based on the best available information, Torrey's 
milkvetch has not recolonized the area (Service 2006a, pp. 1-5).
    (2) In 2003, the Lee Canyon water system was repaired and expanded, 
which included construction of new and replacement waterlines through 
presumed occupied butterfly habitat on Foxtail Ridge adjacent to the 
Lee Canyon Youth Camp and the lower LVSSR parking lot (Location 3 in 
Table 1) (Forest Service 2003a, pp. 1-6). Resource surveys did not 
include butterfly host plants, and the extent of impacts was not 
calculated (Forest Service 2003b, pp. 21-22). Based on the most recent 
survey, Torrey's milkvetch still occurs on Foxtail Ridge (Datasmiths 
2007, pp. 26-27), and it appears that the Lee Canyon water system 
project area has been recolonized by Torrey's milkvetch (Kingsley 2007, 
p. 17); however, the Mt. Charleston blue has not been observed at this 
location since 1998.
    (3) In 2004, the lower LVSSR parking lot was converted into a 
temporary water storage basin (Forest Service 2004a, p. 1). This 
activity included excavation of the parking lot and the construction of 
temporary berms to hold water. Surveys for butterfly host plants were 
not performed, but butterfly host plants were noted in the project area 
as part of a rare plant survey (Hiatt 2004, p. 4). Any larvae, pupae, 
and eggs, along with all vegetation and soil seed bank, would likely 
have been killed while the basin was filled with water. Approximately 2 
ac (0.81 ha) of presumed occupied butterfly habitat were impacted as a 
result of the project (Location 6 in Table 1) (The Urban Wildlands 
Group, Inc. 2005, p. 3). The parking lot continues to be used for 
overflow parking. Recent resource surveys of the area for the proposed 
expansion of the parking lot (see future projects discussion below) 
indicate host plants have not returned to the parking area and remain 
along the perimeter (Datasmiths 2007, pp. 26-27).
    (4) In 2004, the Entrance Walkway Grade Improvement Project 
permanently removed (by paving) 0.186 ac (0.075 ha) of Mt. Charleston 
blue presumed occupied habitat near the main LVSSR parking site for the 
construction of a walkway (Forest Service 2004b, pp. 21-22; Forest 
Service 2004c, pp. 1-3).
    (5) In 2004 and 2005, the LVSSR Snowmaking Line Replacement Project 
impacted approximately 7 ac (2.8 ha) of presumed occupied butterfly 
habitat on the ski runs (Forest Service 2006b, p. 1) and approximately 
0.2 ac (0.08 ha) of known occupied habitat at LVSSR, Upper Lee Canyon 
(Location 2 in Table 1) (The Urban Wildlands Group, Inc. 2005, p. 3; 
Service 2006a, pp. 1-5; Forest Service 2004c, pp. 1-3; Forest Service 
2004d, p. 9; Forest Service 2006b, pp. 1-9). Given the type of 
disturbance, we presume any butterfly larvae, pupae, and eggs would 
have been buried or crushed as a result of trenching and equipment 
access. Revegetation of butterfly habitat impacted from this 
construction was required (Forest Service 2004c, pp. 1-2; 2004d, p. 9-
10), but there are no records available in our files that indicate it 
has been completed (see Factor D).

[[Page 12673]]

    (6) In 2005, the chairlift 1 at LVSSR was replaced. All 
vegetation was removed within equipment travel corridors, laydown 
areas, and construction areas in approximately 4.5 ac (1.8 ha) of 
presumed occupied butterfly habitat (Location 2 in Table 1) (Forest 
Service 2006b, p. 2). Given the level of disturbance, we presume any 
butterfly larvae, pupae, and eggs would have been buried or crushed as 
a result of trenching and equipment access. Revegetation of butterfly 
habitat impacted from this construction was required (Forest Service 
2005c, p. 2; Forest Service 2005d, pp. 12-14; Forest Service 2005e, pp. 
11-12), but there are no records available in our files that indicate 
it has been completed (see Factor D).
    (7) Expansion of the snowmaking pond at LVSSR was first proposed in 
June 2005 and would have permanently impacted 0.48 ac (0.18 ha) of 
presumed occupied butterfly habitat (Forest Service 2005a, pp. 1-25). 
The project was revised to reduce impacts in December 2007 (Forest 
Service 2007b, pp. 1-31) and again in June 2009. Plans for 
implementation included measures to minimize the amount of area 
impacted and mitigate for the loss of any butterfly habitat (Forest 
Service 2009a, p. 18). Construction of the snowmaking pond expansion 
was initiated and completed in 2010. The construction footprint was 
adjacent to one patch of Torrey's milkvetch, and overlapped another 
patch (Forest Service 2010b, Figure 1). A total area of 0.055 ac (0.022 
ha) of Torrey's milkvetch habitat patches was impacted by pond 
expansion construction (Forest Service 2010b, Table 1). Recommendations 
to mitigate for impacted habitat have been prepared (Forest Service 
2010b, pp. 1-5) but not yet implemented. An additional patch of 
previously undocumented Torrey's milkvetch was observed within the 
construction zone in May 2010 (Forest Service 2010a, p. 2), and is not 
included as an area for which mitigation is to be performed (Forest 
Service 2010b, pp. 1-5).
    Future projects are also a threat to the Mt. Charleston blue and 
its habitat. Four recently approved or future projects could impact Mt. 
Charleston blue habitat in Upper Lee Canyon, and are summarized below.
    (1) Expansion of the lower parking lot at LVSSR was proposed in 
June 2005 (Forest Service 2005a, pp. 1-25) and, after revisions to 
reduce impacts to the subspecies' habitat, was reproposed in December 
2007 (Forest Service 2007b, pp. 1-31). Expansion of the lower LVSSR 
parking lot would result in the permanent loss of 2.4 ac (0.97 ha) of 
previously disturbed butterfly habitat and 0.81 ac (0.33 ha) of 
undisturbed presumed occupied butterfly habitat (Location 6 in Table 1) 
(Forest Service 2007b, p. 12). Planning and environmental documents are 
completed for the project; however, final authorization by the USFS has 
not occurred and is currently on hold due to concerns about impacts to 
Mt. Charleston blue (Forest Service 2009a, p. 1).
    (2) The snowmaking system improvements project (new snowmaking 
lines) at LVSSR was proposed in June 2005 (Forest Service 2005a, pp. 1-
2). As proposed, the snowmaking lines expansion project would have 
permanently impacted at that time approximately 8.9 ac (3.6 ha) of 
known occupied butterfly habitat along the two primary ski runs where 
known occupied habitat has been delineated for the Mt. Charleston blue 
(Location 2 in Table 1). The USFS stopped planning efforts for this 
project in 2007 based on the potential impacts to the Mt. Charleston 
blue (Forest Service 2007b, pp. 2).
    (3) A January 2008 draft Master Development Plan for LVSSR proposes 
to improve, upgrade, and expand the existing facilities to provide 
year-round recreational activities. The plan proposes to add winter 
activities such as tubing, MiniZ, snowshoeing, Nordic skiing, climbing 
wall, and Euro-bungee, by widening existing runs to create ``gladed'' 
areas that would provide larger sliding areas (Ecosign 2008, pp. I-3-I-
4). The plan proposes to add summer activities and facilities, 
including mountain biking and bike park, alpine slides, concerts, 
hiking, mountain boards, ziptreks, and stargazing (Ecosign 2008, pp. I-
3-I-4). Summer activities would impact the butterfly and its known 
occupied and presumed occupied habitat (Location 2 in Table 1) by 
attracting visitors in higher numbers during the time of year when 
larvae and host plants are especially vulnerable to trampling. The 
Master Development Plan is in draft form and has not yet been approved 
by the USFS; therefore, no estimate of the potential area of impact is 
available.
    (4) Currently the USFS is planning to restore eroded stream 
channels in Lee Meadows. Repairs to the channels are expected to impact 
presumed occupied butterfly habitat mapped at 1.2 ac (0.50 ha) 
(Location 8 in Table 1) (Forest Service 2009b, p. 10; Datasmiths 2007, 
p. 27). Project implementation began in 2010 and is expected to be 
completed in 2011, and includes measures to minimize impacts to, and 
compensate for the loss of, butterfly habitat (Forest Service 2009b, p. 
10).
Fuels Reduction Projects
    In December 2007, the USFS approved the Spring Mountains National 
Recreation Area Hazardous Fuels Reduction Project (Forest Service 
2007a, pp. 1-127). This project will result in tree removals and 
vegetation thinning in three presumed occupied butterfly locations in 
Upper Lee Canyon, including Foxtail Ridge, Lee Canyon Youth Camp, and 
Lee Meadows, and result in impacts to approximately 32 ac (13 ha) of 
presumed occupied habitat that has been mapped in Upper Lee Canyon 
(Locations 3, 4 and 8 in Table 1) (Forest Service 2007a, Appendix A-Map 
2; Datasmiths 2007, p. 26). Manual and mechanical clearing of shrubs 
and trees will be repeated on a 5- to 10-year rotating basis and will 
result in direct impacts to the butterfly and its habitat, including 
crushing or removal of host plants and diapausing larvae (if present). 
Implementation of this project began in the spring of 2008 throughout 
the Spring Mountains National Recreation Area, including Lee Canyon.
    Although Boyd and Murphy (2008, p. 26) recommended increased forest 
thinning to improve habitat quality for the Mt. Charleston blue, this 
project was designed to reduce wildfire risk to life and property in 
the Spring Mountains National Recreation Area wildland urban interface 
(Forest Service 2007a, p. 6), not to improve Mt. Charleston blue 
habitat. Mt. Charleston blues require larval host plants in exposed 
areas not shaded by forest canopy cover because canopy cover reduces 
solar exposure during critical larval feeding periods (Boyd and Murphy 
2008, p. 23). Shaded fuel breaks created for this project may not be 
open enough to create or significantly improve Mt. Charleston blue 
habitat. Also, shaded fuel breaks for this project are concentrated 
along access roads, property boundaries, campgrounds, picnic areas, 
administrative sites, and communications sites, and are not of 
sufficient spatial scale to reduce the threat identified above 
resulting from fire suppression and succession.
    Although this project may result in increased understory herbaceous 
plant productivity and diversity, there are short-term risks to the 
butterfly associated with project implementation. In recommending 
increased forest thinning to improve Mt. Charleston blue habitat, Boyd 
and Murphy (2008, p. 26) cautioned that thinning treatments would need 
to be implemented carefully to minimize short-term disturbance

[[Page 12674]]

impacts to the butterfly and its habitat. Individual butterflies 
(larvae, pupae, and adults), and larval host plants and nectar plants, 
may be crushed during project implementation. In areas where thinned 
trees are chipped (mastication), layers of wood chips may become too 
deep and impact survival of butterfly larvae and pupae, as well as 
larval host plants and nectar plants. Soil and vegetation disturbance 
during project implementation also could result in increases in weeds 
and disturbance-adapted species, such as Chrysothamnus spp. 
(rabbitbrush), and these plants could compete with Mt. Charleston blue 
larval host and nectar plants.
Conservation Agreements and Plans
    A conservation agreement was developed in 1998 to facilitate 
voluntary cooperation among the USFS, the Service, and the State of 
Nevada Department of Conservation and Natural Resources in providing 
long-term protection for the rare and sensitive flora and fauna of the 
Spring Mountains, including the Mt. Charleston blue (Forest Service 
1998, pp. 1-50). Many of the conservation actions described in the 
conservation agreement have been implemented; however, several 
important conservation actions that would have directly benefited the 
Mt. Charleston blue have not been implemented. Regardless, many of the 
conservation actions in the conservation agreement (e.g., inventory and 
monitoring) would not directly reduce threats to the Mt. Charleston 
blue. In 2004, the Service and USFS signed a memorandum of agreement 
that provides a process for review of activities that involve species 
covered under the 1998 Conservation Agreement (Forest Service and 
Service 2004, pp. 1-9). Formal coordination through this memorandum of 
agreement was established to (1) Jointly develop projects that avoid or 
minimize impacts to listed, candidate and proposed species, and species 
under the 1998 conservation agreement; and (2) to ensure consistency 
with commitments and direction provided for in recovery planning 
efforts and in conservation agreement efforts. More than half of the 
past projects that impacted Mt. Charleston blue habitat were reviewed 
by the Service and USFS under this review process, but several were 
not. Some efforts under this memorandum of agreement have been 
successful in reducing or avoiding project impacts to the butterfly, 
while other efforts have not.
    The loss or modification of known occupied and presumed occupied 
butterfly habitat in Upper Lee Canyon, as discussed above, has occurred 
in the past. However, more recently the USFS has suspended decision on 
certain projects that would potentially impact Mt. Charleston blue 
habitat (see discussion of lower parking lot expansion and new 
snowmaking lines projects under Recreation Development Projects, 
above). In addition, the USFS has recently reaffirmed its commitment to 
collaborate with the Service in order to avoid implementation of 
projects or actions that would impact the viability of (Forest Service 
2010c). This commitment includes: (1) Developing a mutually agreeable 
process to review future proposed projects to ensure that 
implementation of these actions will not lead to loss of viability of 
the species; (2) reviewing proposed projects that may pose a threat to 
the continued viability of the species; and (3) jointly developing a 
conservation agreement (strategy) that identifies actions that will be 
taken to ensure the conservation of the species (Forest Service 2010c).
    The Mt. Charleston blue butterfly is a covered species in the 2000 
Clark County Multiple Species Habitat Conservation Plan (MSHCP). The 
Clark County MSHCP identifies two goals for the Mt. Charleston blue: 
(a) ``Maintain stable or increasing population numbers and host and 
larval plant species''; and (b) ``No net unmitigated loss of larval 
host plant or nectar plant species habitat'' (RECON 2000a, Table 2.5, 
pp. 2-154; RECON 2000b, pp. B158-B161). The USFS is one of several 
signatories to the Implementing Agreement for the Clark County MSHCP, 
because many of the activities from the 1998 Conservation Agreement 
were incorporated into the MSHCP. Primarily, activities undertaken by 
USFS focused on conducting surveying and monitoring for butterflies. 
Although some surveying and monitoring occurred through contracts by 
the USFS, Clark County and the Service, a butterfly monitoring plan was 
not fully implemented.
    Recently, the USFS has been implementing the LVSSR Adaptive 
Vegetation Management Plan (Forest Service 2005b, pp. 1-24) to provide 
mitigation for approximately 11 ac (4.45 ha) of impacts to presumed 
occupied butterfly habitat (and other sensitive wildlife and plant 
species habitat) resulting from projects it implemented in 2005 and 
2006. Under the plan, LVSSR will revegetate impacted areas using native 
plant species, including Torrey's milkvetch. However, this program is 
experimental and has experienced difficulties due to the challenges of 
native seed availability and propagation. Under the plan, Torrey's 
milkvetch is being brought into horticultural propagation, and, if 
successful, plants will begin to be planted in 2011-2013. However, 
these efforts are not likely to provide replacement habitat to the Mt. 
Charleston blue for another 5 years (2016-2018), because of the short 
alpine growing season.
Summary of Factor A
    The Mt. Charleston blue is currently known to occur in two 
locations: The South Loop Trail area in upper Kyle Canyon and LVSSR in 
upper Lee Canyon. Habitat loss and modification as a result of fire 
suppression and long-term successional changes in forest structure, 
implementation of recreational development projects and fuels reduction 
projects, and nonnative species are continuing threats to the butterfly 
in Upper Lee Canyon. Since 2000, seven projects have negatively 
impacted presumed occupied habitat for the Mt. Charleston blue. 
Approved and future projects could negatively impact additional 
presumed occupied occurrences of the Mt. Charleston blue in Lee Canyon 
(identified in Table 1). In addition, if proposed future activities 
under a draft Master Development Plan are approved, they could threaten 
the butterfly, as well as its known occupied and presumed occupied 
habitat at LVSSR.
    Because of its small population size, projects that impact even 
relatively small areas of occupied habitat could threaten the long-term 
population viability of Mt. Charleston blue. The continued loss or 
modification of presumed occupied habitat could further impair the 
long-term population viability of the Mt. Charleston blue in upper Lee 
Canyon by removing diapausing larvae (if present) and by reducing the 
ability of the butterfly to disperse during favorable years. The 
successional advance of trees, shrubs, and grasses and the spread of 
nonnative species are continuing threats to the butterfly in upper Lee 
Canyon. The butterfly is presumed extirpated from at least three of the 
six historical locations, likely due to successional changes and the 
introduction of nonnative plants. Nonnative forbs and grasses are a 
threat to the subspecies at LVSSR.
    Although there are agreements and plans that are intended to 
conserve the Mt. Charleston blue and its habitat, to date, some actions 
under these agreements and plans have not been fully implemented. 
Future actions could be implemented in accordance with the terms of 
various agreements and plans; however, this would be voluntary, and

[[Page 12675]]

other factors may preclude the USFS from doing so. Therefore, based on 
the current distribution and recent, existing, and likely future trends 
in habitat loss, we find the Mt. Charleston blue is threatened by the 
present and future destruction, modification, and curtailment of its 
habitat and range.

Factor B: Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes

    Rare butterflies can be highly prized by insect collectors, and 
collection is a known threat to some butterfly species, such as the 
Fender's blue butterfly (65 FR 3882; January 25, 2000). In particular, 
small colonies and populations are at the highest risk. Overcollection 
or repeated handling and marking of females in years of low abundance 
can seriously damage populations through loss of reproductive 
individuals and genetic variability (65 FR 3882; January 25, 2000). 
Given its diminutive size and similarity to closely related subspecies, 
the Mt. Charleston blue is not likely to be of considerable aesthetic 
interest to collectors or the general public.
    We are not aware of any information that indicates the butterflies 
are being sought by collectors or collected for other purposes. 
Therefore, we do not find that overutilization for commercial, 
recreational, scientific, or educational purposes threatens the Mt. 
Charleston blue.

Factor C: Disease or Predation

    We are not aware of any information regarding any impacts from 
either disease or predation on the Mt. Charleston blue. Therefore, we 
do not find that disease or predation threatens the Mt. Charleston 
blue.

Factor D: The Inadequacy of Existing Regulatory Mechanisms

    Existing regulatory mechanisms or other agreements that could 
provide some protection for the Mt. Charleston blue include: (1) Local 
land use laws, processes, and ordinances; (2) State laws and 
regulations; and (3) Federal laws and regulations. Actions adopted by 
local groups, States, or Federal entities that are discretionary, 
including conservation strategies and guidance, are not regulatory 
mechanisms; however, we will discuss and evaluate them below. The Mt. 
Charleston blue primarily occurs on Federal land under the jurisdiction 
of the USFS; therefore, the discussion below primarily focuses on 
Federal laws.
Local Laws and Ordinances
    We are not aware of any local land use laws or ordinances that have 
been issued by Clark County or other local government entities for 
protection of the Mt. Charleston blue.
State Law
    Nevada Revised Statutes sections 503 and 527 offer protective 
measures to wildlife and plants, but do not include invertebrate 
species such as the Mt. Charleston blue. Therefore, no regulatory 
protection is offered under Nevada State law.
Federal Law
    Mt. Charleston blues have been detected in only two general areas 
in recent years--the South Loop Trail area where adult butterflies were 
recently detected during the summer of 2010 and LVSSR. The South Loop 
Trail area is located along the ridgeline between Griffith Peak and 
Charleston Peak within the Mt. Charleston Wilderness. The U.S. Forest 
Service manages lands designated as wilderness under the Wilderness Act 
of 1964 (16 U.S.C. 1131-1136). Within these areas, the Wilderness Act 
states the following: (1) New or temporary roads cannot be built; (2) 
there can be no use of motor vehicles, motorized equipment, or 
motorboats; (3) there can be no landing of aircraft; (4) there can be 
no other form of mechanical transport; and (5) no structure or 
installation may be built. As such, Mt. Charleston blue habitat in the 
South Loop Trail area is protected from direct loss or degradation by 
the prohibitions of the Wilderness Act. Mt. Charleston blue habitat at 
LVSSR and elsewhere in Lee Canyon and Kyle Canyon is located outside of 
the Mt. Charleston Wilderness, and thus is not subject to protections 
afforded by the Wilderness Act.
    The National Environmental Policy Act (NEPA) of 1969, as amended 
(42 U.S.C. 4321 et seq.), requires Federal agencies, such as the USFS, 
to describe proposed agency actions, consider alternatives, identify 
and disclose potential environmental impacts of each alternative, and 
involve the public in the decision making process. Federal agencies are 
not required to select the NEPA alternative having the least 
significant environmental impacts. A Federal agency may select an 
action that will adversely affect sensitive species provided that these 
effects are identified in a NEPA document. The NEPA itself is a 
disclosure law, and does not require subsequent minimization or 
mitigation of actions taken by Federal agencies. Although Federal 
agencies may include conservation measures for the Mt. Charleston blue 
as a result of the NEPA process, such measures are not required by the 
statute. The USFS is required to analyze its projects, listed under 
Factor A, above, in accordance with the NEPA.
    The Spring Mountains National Recreation Area is one of 10 
districts of the Humboldt-Toiyabe National Forest. Public Law 103-63, 
dated August 4, 1993 (the Spring Mountains National Recreation Area 
Act, 16 U.S.C. 460hhh et seq.), established the Spring Mountains 
National Recreation Area to include approximately 316,000 ac (128,000 
ha) of Federal lands managed by the USFS in Clark and Nye counties, 
Nevada, for the following purposes:
    (1) To preserve the scenic, scientific, historic, cultural, 
natural, wilderness, watershed, riparian, wildlife, threatened and 
endangered species, and other values contributing to public enjoyment 
and biological diversity in the Spring Mountains of Nevada;
    (2) To ensure appropriate conservation and management of natural 
and recreation resources in the Spring Mountains; and
    (3) To provide for the development of public recreation 
opportunities in the Spring Mountains for the enjoyment of present and 
future generations.
    The National Forest Management Act (NFMA) of 1976, as amended (16 
U.S.C. 1600 et seq.), provides the principal guidance for the 
management of activities on lands under USFS jurisdiction, through 
associated land and resource management plans for each forest unit. 
Under NFMA and other Federal laws, the USFS has authority to regulate 
recreation, vehicle travel and other human disturbance, livestock 
grazing, fire management, energy development, and mining on lands 
within its jurisdiction. Current guidance for the management of USFS 
lands in the Spring Mountains National Recreation Area is under the 
Toiyabe National Forest Land and Resource Management Plan and the 
Spring Mountains National Recreation Area General Management Plan. In 
June 2006, the USFS added the Mt. Charleston blue, and three other 
endemic butterflies, to the Regional Forester's Sensitive Species List 
in accordance with Forest Service Manual 2670. The objectives of the 
USFS to manage sensitive species are to prevent listing of species 
under the Act, maintain viable populations of native species, and 
develop and implement management objectives for populations and habitat 
of sensitive species. All of the projects listed in Factor A, above, 
have been guided by these USFS plans, policies, and guidance. These 
plans, policies, and

[[Page 12676]]

guidance notwithstanding, removal or degradation of known occupied and 
presumed occupied butterfly habitat has occurred as a result of 
projects approved by the USFS in upper Lee Canyon. Additionally, this 
guidance has not been effective in reducing other threats to the Mt. 
Charleston blue (e.g., nonnative plant species).
Summary of Factor D
    Existing regulatory mechanisms are not sufficient to provide for 
conservation of the Mt. Charleston blue. Nevada Revised Statutes 
sections 503 and 527 do offer protective measures to wildlife and 
plants, but do not specifically include protections for invertebrate 
species, such as the Mt. Charleston blue. Since applicable State 
regulatory mechanisms that could potentially protect the Mt. Charleston 
blue are not inclusive of invertebrates, they are not effective in 
relieving the threats faced by the Mt. Charleston blue butterfly. 
Although Mt. Charleston blue habitat at the South Loop Trail area is 
protected by prohibitions of the Wilderness Act from many types of 
habitat-disturbing actions, habitat where Mt. Charleston blues have 
occurred in the past within Lee Canyon and Kyle Canyon are outside of 
designated wilderness and thus not protected by prohibitions of the 
Wilderness Act. Because of the Mt. Charleston blue's extremely small 
population size and limited distribution, it is potentially vulnerable 
to projects or actions that impact even relatively small areas of 
occupied or suitable habitat. Because existing law, regulation, and 
policy have not prevented implementation of projects or actions that 
have resulted in loss or degradation of butterfly habitat (see Factor 
A), we conclude that existing regulatory mechanisms are inadequate to 
protect the Mt. Charleston blue from threats discussed in this finding.

Factor E: Other Natural or Manmade Factors Affecting the Continued 
Existence of the Species

    The Mt. Charleston blue population appears to have declined since 
the last high-population year in 1995. This subspecies has a limited 
distribution, and population numbers are small. Small butterfly 
populations have a higher risk of extinction due to random 
environmental events (Shaffer 1981, p. 131; Shaffer 1987, pp. 69-75; 
Gilpin and Soule 1986, pp. 24-28). Weather extremes can cause severe 
butterfly population reductions or extinctions (Murphy et al. 1990, p. 
43; Weiss et al. 1987, pp. 164-167; Thomas et al. 1996, pp. 964-969). 
Given the limited distribution and likely low population numbers of the 
Mt. Charleston blue, late-season snowstorms, severe summer monsoon 
thunderstorms, and drought have the potential to adversely impact the 
subspecies.
    Late-season snowstorms have caused alpine butterfly extirpations 
(Ehrlich et al. 1972, pp. 101-105), and false spring conditions 
followed by normal winter snowstorms have caused adult and pre-diapause 
larvae mortality (Parmesan 2005, pp. 56-60). In addition, high rainfall 
years have been associated with butterfly population declines (Dobkin 
et al. 1987, pp. 161-176). Extended periods of rainy weather can also 
slow larval development and reduce overwintering survival (Weiss et al. 
1993, pp. 261-270). Weiss et al. (1997, p. 32) suggested that heavy 
summer monsoon thunderstorms adversely impacted Mt. Charleston blue 
butterflies during the 1996 flight season. During the 2006 and 2007 
flight season, severe summer thunderstorms may have affected the flight 
season at LVSSR and the South Loop Trail (Newfields 2006, pp. 11 and 
14; Kingsley 2007, p. 8). Additionally, drought has been shown to lower 
butterfly populations (Ehrlich et al. 1980, pp. 101-105; Thomas 1984, 
p. 344). Drought can cause butterfly host plants to mature early and 
reduce larval food availability (Ehrlich et al. 1980, pp. 101-105; 
Weiss 1987, p. 165). This has likely affected the Mt. Charleston blue. 
Murphy (2006, p. 3) and Boyd (2006, p. 1) both assert a series of 
drought years, followed by a season of above-average snowfall and then 
more drought, could be a reason for the lack of butterfly sightings in 
2006. Continuing drought could be responsible for the lack of sightings 
in 2007 and 2008 (Datasmiths 2007, p. 1; Boyd 2008, p. 2).
    High-elevation species like the Mt. Charleston blue may be 
particularly susceptible to some level of habitat loss due to global 
climate change exacerbating threats already facing the subspecies 
(Peters and Darling 1985, p. 714; Hill et al. 2002, p. 2170). The 
Intergovernmental Panel on Climate Change (IPCC) has high confidence in 
predictions that extreme weather events, warmer temperatures, and 
regional drought are very likely to increase in the northern hemisphere 
as a result of climate change (IPCC 2007, pp. 15-16). Climate models 
show the southwestern United States has transitioned into a more arid 
climate of drought that is predicted to continue into the next century 
(Seager et al. 2007, p. 1181). In the past 60 years, the frequency of 
storms with extreme precipitation has increased in Nevada by 29 percent 
(Madsen and Figdor 2007, p. 37). Changes in local southern Nevada 
climatic patterns cannot be definitively tied to global climate change; 
however, they are consistent with IPCC-predicted patterns of extreme 
precipitation, warmer than average temperatures, and drought (Redmond 
2007, p. 1). Therefore, we think it likely that climate change will 
impact the Mt. Charleston blue and its high-elevation habitat through 
predicted increases in extreme precipitation and drought. Alternating 
extreme precipitation and drought may exacerbate threats already facing 
the subspecies as a result of its small population size and threats to 
its habitat.
Summary of Factor E
    Small butterfly populations have a higher risk of extinction due to 
random environmental events (Shaffer 1981, p. 131; Gilpin and Soule 
1986, pp. 24-28; Shaffer 1987, pp. 69-75). Because of its small 
population and restricted range, the Mt. Charleston blue is vulnerable 
to random environmental events; in particular, the butterfly is 
threatened by extreme precipitation events and drought. In the past 60 
years, the frequency of storms with extreme precipitation has increased 
in Nevada by 29 percent (Madsen and Figdor 2007, p. 37), and it is 
predicted that altered regional patterns of temperature and 
precipitation as a result of global climate change will continue (IPCC 
2007, pp. 15-16). Throughout the entire range of the Mt. Charleston 
blue, altered climate patterns could increase the potential for extreme 
precipitation events and drought, and may exacerbate the threats the 
subspecies already faces given its small population size and the 
threats to the alpine environment where it occurs. Based on this 
information, we find that other natural or manmade factors are 
affecting the Mt. Charleston blue such that these factors threaten the 
subspecies' continued existence.

Summary of Threats Analysis

    The Mt. Charleston blue butterfly is sensitive to environmental 
variability with the butterfly population rising and falling in 
response to environmental conditions (see ``Status and Trends'' 
section). The best available information suggests the Mt. Charleston 
blue population appears to have been in decline since 1995, the last 
year the subspecies was observed in high numbers, and that the 
population is now extremely small (see ``Status and Trends'' section). 
To some extent the Mt. Charleston blue, like most butterflies, has 
evolved to survive unfavorable environmental conditions as diapausing 
larvae or pupae (Scott 1986, pp. 26-30). The pupae of some butterfly 
species are

[[Page 12677]]

known to persist in diapause up to 5 to 7 years (Scott 1986, p. 28). 
The number of years the Mt. Charleston blue can remain in diapause is 
unknown. Local experts have speculated that the Mt. Charleston blue may 
only be able to diapause for one season. However, in response to 
unfavorable environmental conditions, it is hypothesized that a 
prolonged diapause period may be possible (Murphy 2006, p. 1; 
Datasmiths 2007, p. 6; Boyd and Murphy 2008, p. 22). The best available 
information suggests environmental conditions from 2006 to 2009 have 
not been favorable to the butterfly (see ``Status and Trends'' 
section).
    Surveys are planned for 2011 to further determine the status and 
provide more knowledge about the ecology of the Mt. Charleston blue. 
Threats facing the Mt. Charleston blue, discussed above under listing 
Factors A, D, and E, will only increase risks to persistence of the 
butterfly, given its low population size. The loss and degradation of 
habitat due to fire suppression and succession; implementation of 
recreation development projects and fuels reduction projects; and 
increases in nonnative plants (see Factor A), along with the lack of 
adequate regulatory mechanisms to prevent these impacts (see Factor D), 
will increase the inherent risk of extinction of the remaining small 
population of Mt. Charleston blue. These threats are likely to be 
exacerbated by the impact of climate change, which is anticipated to 
increase drought and extreme precipitation events (see Factor E).

Finding

    As required by the Act, we considered the five factors in assessing 
whether the Mt. Charleston blue butterfly is endangered or threatened 
throughout all or a significant portion of its range. We have carefully 
examined the best scientific and commercial information available 
regarding the past, present, and future threats faced by the Mt. 
Charleston blue. We reviewed the petition, information available in our 
files, other available published and unpublished information, 
information obtained from consultations with recognized Mt. Charleston 
blue butterfly experts, and information submitted to us by the public 
following publication of our notice of 90-day petition finding and 
initiation of status review (72 FR 29933; May 30, 2007). On the basis 
of the best scientific and commercial information available, we find 
that the listing of the Mt. Charleston blue butterfly is warranted, due 
to the threats associated with habitat destruction or modification 
(Factor A), the inadequacy of existing regulatory mechanisms (Factor 
D), and other natural and manmade factors (Factor E). We will make a 
determination on the status of the species as endangered or threatened 
when we prepare a proposed listing rule. However, as explained in more 
detail below, an immediate proposal of a regulation implementing this 
action is precluded by higher priority listing actions, and progress is 
being made to add or remove qualified species from the Lists of 
Endangered and Threatened Wildlife and Plants.
    In making this finding, we recognize that there have been declines 
in the distribution and abundance of the Mt. Charleston blue as a 
result of natural and human-caused factors. Butterflies that occur in 
upper Lee Canyon are threatened by fire suppression and succession, 
implementation of recreation development projects and fuels reduction 
projects, and increases in nonnative plant species. These threats, if 
left unchecked, could continue to impair the long-term population 
viability of the Mt. Charleston blue (Factor A). In addition, the 
existing voluntary agreements and plans (Factor A), and regulatory 
mechanisms (Factor D) are inadequate to sufficiently reduce the threats 
to the subspecies from habitat loss and degradation and nonnative 
species to a level that does not pose a significant threat to the 
subspecies. The amount of known habitat persistently occupied at the 
South Loop Trail and LVSSR is small (less than 23 ac (9 ha)). The 
threats to the viability of the Mt. Charleston blue because of its 
limited distribution, extremely low population numbers, and degradation 
of its habitat will be exacerbated by threats from extreme 
precipitation events and drought that are predicted to become more 
frequent under global climate change (Factor E). Due to the threats 
described above, we find that the Mt. Charleston blue butterfly is 
warranted for listing throughout its range; however, the promulgation 
of a listing rule at this time is precluded by higher priority listing 
actions. We will review whether to list the Mt. Charleston blue 
butterfly as endangered or threatened when we begin the process to 
propose listing of this subspecies, as our priorities allow. We will 
make any determination on critical habitat during development of the 
proposed listing rule.
    We have reviewed the available information to determine if the 
existing and foreseeable threats render the species at risk of 
extinction now such that issuing an emergency regulation temporarily 
listing the species under section 4(b)(7) of the Act is appropriate. 
During this status review, we considered whether emergency listing of 
the subspecies was necessary, given the vulnerability of the Mt. 
Charleston blue to extinction due to its small population size and 
limited distribution. We have determined that, at this time, issuing an 
emergency regulation temporarily putting the protections of the Act in 
place for the subspecies is not appropriate for the following reasons. 
Nearly the entire range of the Mt. Charleston blue is located on public 
lands managed by the Humboldt-Toiyabe National Forest, so habitats on 
these lands are not subject to large-scale development pressures that 
may occur on private lands. The area where the most persistent 
population of Mt. Charleston blue currently occurs is the South Loop 
Trail area, which is located within the Mt. Charleston Wilderness, and 
thus receives protection afforded by the the Wilderness Act (see Factor 
D discussion). In addition, decisions on proposed projects that would 
have impacted Mt. Charleston blue habitat at the LVSSR have been 
suspended or modified recently (see Recreation Development Projects 
under Factor A), and the USFS has recently reaffirmed its commitment to 
ensure that implementation of projects and actions on Forest Service 
lands will not cause a loss of viability of the Mt. Charleston blue 
(see Conservation Agreements and Plans under Factor A). However, if the 
current situation changes and we become aware of projects or actions 
that pose an immediate threat to the continued existence of the Mt. 
Charleston blue, we may act immediately to provide the butterfly 
emergency protections under the Act.

Listing Priority Number

    The Service adopted guidelines on September 21, 1983 (48 FR 43098) 
to establish a rational system for utilizing available resources for 
the highest priority species when adding species to the Lists of 
Endangered or Threatened Wildlife and Plants or reclassifying species 
listed as threatened to endangered status. These guidelines, titled 
``Endangered and Threatened Species Listing and Recovery Priority 
Guidelines'' (LPN Guidance) address the immediacy and magnitude of 
threats, and the level of taxonomic distinctiveness by assigning 
priority in descending order to monotypic genera (genus with one 
species), full species, and subspecies (or equivalently, distinct 
population segments of vertebrates). We assigned the Mt. Charleston 
blue butterfly a Listing Priority Number (LPN) of 3 based on our 
finding that the

[[Page 12678]]

species faces threats that are of high magnitude and are imminent. 
Because the Mt. Charleston blue butterfly is a subspecies, the highest 
Listing Priority Number (LPN) we can assign it is an LPN of 3, which is 
the highest priority that can be provided to a subspecies under our LPN 
Guidance. Our rationale for assigning the Mt. Charleston blue butterfly 
an LPN of 3 is outlined below.
    Under the Service's LPN Guidance, the magnitude of threat is the 
first criterion we look at when establishing a listing priority. The 
guidance indicates that species with the highest magnitude of threat 
are those species facing the greatest threats to their continued 
existence. These species receive the highest listing priority. Mt. 
Charleston blue is highly vulnerable to threats because of its 
extremely small population size and limited distribution. The magnitude 
of threats to the Mt. Charleston blue is high due to a combination of 
existing threats. These threats include habitat loss and degradation 
due to fire suppression and succession, implementation of fuels 
reduction projects and habitat-disturbing projects or actions, and 
spread of nonnative plants (Factor A). In addition, because of its 
extremely limited range, drought and extreme precipitation events, 
which are predicted to become more frequent under climate change, 
potentially impact Mt. Charleston blue across its entire range (Factor 
E). These threats act synergistically and constitute a significant risk 
to the continued existence of the Mt. Charleston blue. Given the 
decline in the population of the Mt. Charleston blue butterfly over the 
last 15 years, active and sustained conservation of the butterfly and 
its habitat is required.
    Under our LPN Guidance, the second criterion we consider in 
assigning a listing priority is the immediacy of threats. This 
criterion is intended to ensure that the species that face actual, 
identifiable threats are given priority over those for which threats 
are only potential or species that are intrinsically vulnerable but are 
not known to be presently facing such threats. The threats described 
above in this finding are imminent because they are ongoing. The 
combination of ongoing threats place the continued existence of the Mt. 
Charleston blue at risk because of its high vulnerability due to 
extremely small population size and limited distribution.
    The third criterion in our LPN guidance is intended to ensure 
resources are devoted to those species representing highly distinctive 
or isolated gene pools as reflected by taxonomy. The Mt. Charleston 
blue butterfly is a valid taxon at the subspecies level, and therefore 
receives a lower priority than a full species or a species in a 
monotypic genus. The Mt. Charleston blue butterfly faces high-
magnitude, imminent threats, and is a valid taxon at the subspecies 
level. Thus, in accordance with our LPN guidance, we have assigned the 
Mt. Charleston blue butterfly an LPN of 3.
    We will continue to monitor the threats to the Mt. Charleston blue 
butterfly, and the subspecies' status on an annual basis, and should 
the magnitude or the imminence of the threats change, we will revisit 
our assessment of the LPN.
    Work on a proposed listing determination for the Mt. Charleston 
blue butterfly is precluded by work on higher priority listing actions 
with absolute statutory, court-ordered, or court-approved deadlines and 
final listing determinations for those species that were proposed for 
listing with funds from Fiscal Year 2011. This work includes all the 
actions listed in the tables below under expeditious progress.

Preclusion and Expeditious Progress

    Preclusion is a function of the listing priority of a species in 
relation to the resources that are available and the cost and relative 
priority of competing demands for those resources. Thus, in any given 
fiscal year (FY), multiple factors dictate whether it will be possible 
to undertake work on a listing proposal regulation or whether 
promulgation of such a proposal is precluded by higher-priority listing 
actions.
    The resources available for listing actions are determined through 
the annual Congressional appropriations process. The appropriation for 
the Listing Program is available to support work involving the 
following listing actions: Proposed and final listing rules; 90-day and 
12-month findings on petitions to add species to the Lists of 
Endangered and Threatened Wildlife and Plants (Lists) or to change the 
status of a species from threatened to endangered; annual 
``resubmitted'' petition findings on prior warranted-but-precluded 
petition findings as required under section 4(b)(3)(C)(i) of the Act; 
critical habitat petition findings; proposed and final rules 
designating critical habitat; and litigation-related, administrative, 
and program-management functions (including preparing and allocating 
budgets, responding to Congressional and public inquiries, and 
conducting public outreach regarding listing and critical habitat). The 
work involved in preparing various listing documents can be extensive 
and may include, but is not limited to: Gathering and assessing the 
best scientific and commercial data available and conducting analyses 
used as the basis for our decisions; writing and publishing documents; 
and obtaining, reviewing, and evaluating public comments and peer 
review comments on proposed rules and incorporating relevant 
information into final rules. The number of listing actions that we can 
undertake in a given year also is influenced by the complexity of those 
listing actions; that is, more complex actions generally are more 
costly. The median cost for preparing and publishing a 90-day finding 
is $39,276; for a 12-month finding, $100,690; for a proposed rule with 
critical habitat, $345,000; and for a final listing rule with critical 
habitat, the median cost is $305,000.
    We cannot spend more than is appropriated for the Listing Program 
without violating the Anti-Deficiency Act (see 31 U.S.C. 
1341(a)(1)(A)). In addition, in FY 1998 and for each fiscal year since 
then, Congress has placed a statutory cap on funds which may be 
expended for the Listing Program, equal to the amount expressly 
appropriated for that purpose in that fiscal year. This cap was 
designed to prevent funds appropriated for other functions under the 
Act (for example, recovery funds for removing species from the Lists), 
or for other Service programs, from being used for Listing Program 
actions (see House Report 105-163, 105th Congress, 1st Session, July 1, 
1997).
    Since FY 2002, the Service's budget has included a critical habitat 
subcap to ensure that some funds are available for other work in the 
Listing Program (``The critical habitat designation subcap will ensure 
that some funding is available to address other listing activities'' 
(House Report No. 107-103, 107th Congress, 1st Session, June 19, 
2001)). In FY 2002 and each year until FY 2006, the Service has had to 
use virtually the entire critical habitat subcap to address court-
mandated designations of critical habitat, and consequently none of the 
critical habitat subcap funds have been available for other listing 
activities. In some FYs since 2006, we have been able to use some of 
the critical habitat subcap funds to fund proposed listing 
determinations for high-priority candidate species. In other FYs, while 
we were unable to use any of the critical habitat subcap funds to fund 
proposed listing determinations, we did use some of this money to fund 
the critical habitat portion of some proposed listing determinations so 
that the proposed

[[Page 12679]]

listing determination and proposed critical habitat designation could 
be combined into one rule, thereby being more efficient in our work. At 
this time, for FY 2011, we do not know if we will be able to use some 
of the critical habitat subcap funds to fund proposed listing 
determinations.
    We make our determinations of preclusion on a nationwide basis to 
ensure that the species most in need of listing will be addressed first 
and also because we allocate our listing budget on a nationwide basis. 
Through the listing cap, the critical habitat subcap, and the amount of 
funds needed to address court-mandated critical habitat designations, 
Congress and the courts have in effect determined the amount of money 
available for other listing activities nationwide. Therefore, the funds 
in the listing cap, other than those needed to address court-mandated 
critical habitat for already listed species, set the limits on our 
determinations of preclusion and expeditious progress.
    Congress identified the availability of resources as the only basis 
for deferring the initiation of a rulemaking that is warranted. The 
Conference Report accompanying Public Law 97-304 (Endangered Species 
Act Amendments of 1982), which established the current statutory 
deadlines and the warranted-but-precluded finding, states that the 
amendments were ``not intended to allow the Secretary to delay 
commencing the rulemaking process for any reason other than that the 
existence of pending or imminent proposals to list species subject to a 
greater degree of threat would make allocation of resources to such a 
petition [that is, for a lower-ranking species] unwise.'' Although that 
statement appeared to refer specifically to the ``to the maximum extent 
practicable'' limitation on the 90-day deadline for making a 
``substantial information'' finding, that finding is made at the point 
when the Service is deciding whether or not to commence a status review 
that will determine the degree of threats facing the species, and 
therefore the analysis underlying the statement is more relevant to the 
use of the warranted-but-precluded finding, which is made when the 
Service has already determined the degree of threats facing the species 
and is deciding whether or not to commence a rulemaking.
    In FY 2011, on December 22, 2010, Congress passed a continuing 
resolution which provides funding at the FY 2010 enacted level through 
March 4, 2011. Until Congress appropriates funds for FY 2011 at a 
different level, we will fund listing work based on the FY 2010 amount. 
Thus, at this time in FY 2011, the Service anticipates an appropriation 
of $22,103,000 based on FY 2010 appropriations. Of that, the Service 
anticipates needing to dedicate $11,632,000 for determinations of 
critical habitat for already listed species. Also $500,000 is 
appropriated for foreign species listings under the Act. The Service 
thus has $9,971,000 available to fund work in the following categories: 
Compliance with court orders and court-approved settlement agreements 
requiring that petition findings or listing determinations be completed 
by a specific date; section 4 (of the Act) listing actions with 
absolute statutory deadlines; essential litigation-related, 
administrative, and listing program-management functions; and high-
priority listing actions for some of our candidate species. In FY 2010 
the Service received many new petitions and a single petition to list 
404 species. The receipt of petitions for a large number of species is 
consuming the Service's listing funding that is not dedicated to 
meeting court-ordered commitments. Absent some ability to balance 
effort among listing duties under existing funding levels, it is 
unlikely that the Service will be able to initiate any new listing 
determination for candidate species in FY 2011.
    In 2009, the responsibility for listing foreign species under the 
Act was transferred from the Division of Scientific Authority, 
International Affairs Program, to the Endangered Species Program. 
Therefore, starting in FY 2010, we used a portion of our funding to 
work on the actions described above for listing actions related to 
foreign species. In FY 2011, we anticipate using $1,500,000 for work on 
listing actions for foreign species which reduces funding available for 
domestic listing actions, however, currently only $500,000 has been 
allocated. Although there are currently no foreign species issues 
included in our high-priority listing actions at this time, many 
actions have statutory or court-approved settlement deadlines, thus 
increasing their priority. The budget allocations for each specific 
listing action are identified in the Service's FY 2011 Allocation Table 
(part of our record).
    For the above reasons, funding a proposed listing determination for 
the Mt. Charleston blue is precluded by court-ordered and court-
approved settlement agreements, listing actions with absolute statutory 
deadlines, and work on proposed listing determinations for those 
candidate species with a higher listing priority (i.e., candidate 
species with LPNs of 1-2.
    Based on our September 21, 1983, guidance for assigning an LPN for 
each candidate species (48 FR 43098), we have a significant number of 
species with an LPN of 2. Using this guidance, we assign each candidate 
an LPN of 1 to 12, depending on the magnitude of threats (high or 
moderate to low), immediacy of threats (imminent or nonimminent), and 
taxonomic status of the species (in order of priority: Monotypic genus 
(a species that is the sole member of a genus); species; or part of a 
species (subspecies, distinct population segment, or significant 
portion of the range)). The lower the listing priority number, the 
higher the listing priority (that is, a species with an LPN of 1 would 
have the highest listing priority).
    Because of the large number of high-priority species, we have 
further ranked the candidate species with an LPN of 2 by using the 
following extinction-risk type criteria: International Union for the 
Conservation of Nature and Natural Resources (IUCN) Red list status/
rank, Heritage rank (provided by NatureServe), Heritage threat rank 
(provided by NatureServe), and species currently with fewer than 50 
individuals, or 4 or fewer populations. Those species with the highest 
IUCN rank (critically endangered), the highest Heritage rank (G1), the 
highest Heritage threat rank (substantial, imminent threats), and 
currently with fewer than 50 individuals, or fewer than 4 populations, 
originally comprised a group of approximately 40 candidate species 
(``Top 40''). These 40 candidate species have had the highest priority 
to receive funding to work on a proposed listing determination. As we 
work on proposed and final listing rules for those 40 candidates, we 
apply the ranking criteria to the next group of candidates with an LPN 
of 2 and 3 to determine the next set of highest priority candidate 
species. Finally, proposed rules for reclassification of threatened 
species to endangered are lower priority, since as listed species, they 
are already afforded the protection of the Act and implementing 
regulations. However, for efficiency reasons, we may choose to work on 
a proposed rule to reclassify a species to endangered if we can combine 
this with work that is subject to a court-determined deadline.
    With our workload so much bigger than the amount of funds we have 
to accomplish it, it is important that we be as efficient as possible 
in our listing process. Therefore, as we work on proposed rules for the 
highest priority species in the next several years, we are preparing 
multi-species proposals when appropriate, and these may include

[[Page 12680]]

species with lower priority if they overlap geographically or have the 
same threats as a species with an LPN of 2. In addition, we take into 
consideration the availability of staff resources when we determine 
which high-priority species will receive funding to minimize the amount 
of time and resources required to complete each listing action.
    As explained above, a determination that listing is warranted but 
precluded must also demonstrate that expeditious progress is being made 
to add and remove qualified species to and from the Lists of Endangered 
and Threatened Wildlife and Plants. As with our ``precluded'' finding, 
the evaluation of whether progress in adding qualified species to the 
Lists has been expeditious is a function of the resources available for 
listing and the competing demands for those funds. (Although we do not 
discuss it in detail here, we are also making expeditious progress in 
removing species from the list under the Recovery program in light of 
the resource available for delisting, which is funded by a separate 
line item in the budget of the Endangered Species Program. So far 
during FY 2011, we have completed one delisting rule.) Given the 
limited resources available for listing, we find that we are making 
expeditious progress in FY 2011 in the Listing. This progress included 
preparing and publishing the following determinations:

                                        FY 2011 Completed Listing Actions
----------------------------------------------------------------------------------------------------------------
       Publication date                 Title                 Actions                      FR pages
----------------------------------------------------------------------------------------------------------------
10/6/2010.....................  Endangered Status for  Proposed Listing      75 FR 61664-61690
                                 the Altamaha           Endangered.
                                 Spinymussel and
                                 Designation of
                                 Critical Habitat.
10/7/2010.....................  12-Month Finding on a  Notice of 12-month    75 FR 62070-62095
                                 Petition to list the   petition finding,
                                 Sacramento Splittail   Not warranted.
                                 as Endangered or
                                 Threatened.
10/28/2010....................  Endangered Status and  Proposed Listing      75 FR 66481-66552
                                 Designation of         Endangered
                                 Critical Habitat for   (uplisting).
                                 Spikedace and Loach
                                 Minnow.
11/2/2010.....................  90-Day Finding on a    Notice of 90-day      75 FR 67341-67343
                                 Petition to List the   Petition Finding,
                                 Bay Springs            Not substantial.
                                 Salamander as
                                 Endangered.
11/2/2010.....................  Determination of       Final Listing         75 FR 67511-67550
                                 Endangered Status      Endangered.
                                 for the Georgia
                                 Pigtoe Mussel,
                                 Interrupted
                                 Rocksnail, and Rough
                                 Hornsnail and
                                 Designation of
                                 Critical Habitat.
11/2/2010.....................  Listing the Rayed      Proposed Listing      75 FR 67551-67583
                                 Bean and Snuffbox as   Endangered.
                                 Endangered.
11/4/2010.....................  12-Month Finding on a  Notice of 12-month    75 FR 67925-67944
                                 Petition to List       petition finding,
                                 Cirsium wrightii       Warranted but
                                 (Wright's Marsh        precluded.
                                 Thistle) as
                                 Endangered or
                                 Threatened.
12/14/2010....................  Endangered Status for  Proposed Listing      75 FR 77801-77817
                                 Dunes Sagebrush        Endangered.
                                 Lizard.
12/14/2010....................  12-Month Finding on a  Notice of 12-month    75 FR 78029-78061
                                 Petition to List the   petition finding,
                                 North American         Warranted but
                                 Wolverine as           precluded.
                                 Endangered or
                                 Threatened.
12/14/2010....................  12-Month Finding on a  Notice of 12-month    75 FR 78093-78146
                                 Petition to List the   petition finding,
                                 Sonoran Population     Warranted but
                                 of the Desert          precluded.
                                 Tortoise as
                                 Endangered or
                                 Threatened.
12/15/2010....................  12-Month Finding on a  Notice of 12-month    75 FR 78513-78556
                                 Petition to List       petition finding,
                                 Astragalus             Warranted but
                                 microcymbus and        precluded.
                                 Astragalus
                                 schmolliae as
                                 Endangered or
                                 Threatened.
12/28/2010....................  Listing Seven          Final Listing         75 FR 81793-81815
                                 Brazilian Bird         Endangered.
                                 Species as
                                 Endangered
                                 Throughout Their
                                 Range.
1/4/2011......................  90-Day Finding on a    Notice of 90-day      76 FR 304-311
                                 Petition to List the   Petition Finding,
                                 Red Knot subspecies    Not substantial.
                                 Calidris canutus
                                 roselaari as
                                 Endangered.
1/19/2011.....................  Endangered Status for  Proposed Listing      76 FR 3392-3420
                                 the Sheepnose and      Endangered.
                                 Spectaclecase
                                 Mussels.
2/10/2011.....................  12-Month Finding on a  Notice of 12-month    76 FR 7634
                                 Petition to List the   petition finding,
                                 Pacific Walrus as      Warranted but
                                 Endangered or          precluded.
                                 Threatened.
----------------------------------------------------------------------------------------------------------------

    Our expeditious progress also includes work on listing actions that 
we funded in FY 2010 and FY 2011 but have not yet been completed to 
date. These actions are listed below. Actions in the top section of the 
table are being conducted under a deadline set by a court. Actions in 
the middle section of the table are being conducted to meet statutory 
timelines, that is, timelines required under the Act. Actions in the 
bottom section of the table are high-priority listing actions. These 
actions include work primarily on species with an LPN of 2, and, as 
discussed above, selection of these species is partially based on 
available staff resources, and when appropriate, include species with a 
lower priority if they overlap geographically or have the same threats 
as the species with the high priority. Including these species together 
in the same proposed rule results in considerable savings in time and 
funding, as compared to preparing separate proposed rules for each of 
them in the future.

[[Page 12681]]



                           Actions Funded in FY 2010 and FY 2011 but not yet Completed
----------------------------------------------------------------------------------------------------------------
                      Species                                                  Action
----------------------------------------------------------------------------------------------------------------
                               Actions Subject to Court Order/Settlement Agreement
----------------------------------------------------------------------------------------------------------------
Flat-tailed horned lizard.........................  Final listing determination.
Mountain plover \4\...............................  Final listing determination.
Solanum conocarpum................................  12-month petition finding.
Thorne's Hairstreak butterfly \3\.................  12-month petition finding.
Hermes copper butterfly \3\.......................  12-month petition finding.
4 parrot species (military macaw, yellow-billed     12-month petition finding.
 parrot, red-crowned parrot, scarlet macaw) \5\.
4 parrot species (blue-headed macaw, great green    12-month petition finding.
 macaw, grey-cheeked parakeet, hyacinth macaw) \5\.
4 parrots species (crimson shining parrot, white    12-month petition finding.
 cockatoo, Philippine cockatoo, yellow-crested
 cockatoo) \5\.
Utah prairie dog (uplisting)......................  90-day petition finding.
----------------------------------------------------------------------------------------------------------------
                                        Actions with Statutory Deadlines
----------------------------------------------------------------------------------------------------------------
Casey's june beetle...............................  Final listing determination.
Southern rockhopper penguin--Campbell Plateau       Final listing determination.
 population.
6 Birds from Eurasia..............................  Final listing determination.
5 Bird species from Colombia and Ecuador..........  Final listing determination.
Queen Charlotte goshawk...........................  Final listing determination.
5 species southeast fish (Cumberland darter, rush   Final listing determination.
 darter, yellowcheek darter, chucky madtom, and
 laurel dace) \4\.
Ozark hellbender \4\..............................  Final listing determination.
Altamaha spinymussel \3\..........................  Final listing determination.
3 Colorado plants (Ipomopsis polyantha (Pagosa      Final listing determination.
 Skyrocket), Penstemon debilis (Parachute
 Beardtongue), and Phacelia submutica (DeBeque
 Phacelia)) \4\.
Salmon crested cockatoo...........................  Final listing determination.
6 Birds from Peru and Bolivia.....................  Final listing determination.
Loggerhead sea turtle (assist National Marine       Final listing determination.
 Fisheries Service) \5\.
2 mussels (rayed bean (LPN = 2), snuffbox No LPN)   Final listing determination.
 \5\.
Mt Charleston blue \5\............................  Proposed listing determination.
CA golden trout \4\...............................  12-month petition finding.
Black-footed albatross............................  12-month petition finding.
Mount Charleston blue butterfly...................  12-month petition finding.
Mojave fringe-toed lizard \1\.....................  12-month petition finding.
Kokanee--Lake Sammamish population \1\............  12-month petition finding.
Cactus ferruginous pygmy-owl \1\..................  12-month petition finding.
Northern leopard frog.............................  12-month petition finding.
Tehachapi slender salamander......................  12-month petition finding.
Coqui Llanero.....................................  12-month petition finding/Proposed listing.
Dusky tree vole...................................  12-month petition finding.
3 MT invertebrates (mist forestfly (Lednia          12-month petition finding.
 tumana), Oreohelix sp.3, Oreohelix sp. 31) from
 206 species petition.
5 UT plants (Astragalus hamiltonii, Eriogonum       12-month petition finding.
 soredium, Lepidium ostleri, Penstemon flowersii,
 Trifolium friscanum) from 206 species petition.
5 WY plants (Abronia ammophila, Agrostis rossiae,   12-month petition finding.
 Astragalus proimanthus, Boechere (Arabis)
 pusilla, Penstemon gibbensii) from 206 species
 petition.
Leatherside chub (from 206 species petition)......  12-month petition finding.
Frigid ambersnail (from 206 species petition) \3\.  12-month petition finding.
Platte River caddisfly (from 206 species petition)  12-month petition finding.
 \5\.
Gopher tortoise--eastern population...............  12-month petition finding.
Grand Canyon scorpion (from 475 species petition).  12-month petition finding.
Anacroneuria wipukupa (a stonefly from 475 species  12-month petition finding.
 petition) \4\.
Rattlesnake-master borer moth (from 475 species     12-month petition finding.
 petition) \3\.
3 Texas moths (Ursia furtiva, Sphingicampa          12-month petition finding.
 blanchardi, Agapema galbina) (from 475 species
 petition).
2 Texas shiners (Cyprinella sp., Cyprinella         12-month petition finding.
 lepida) (from 475 species petition).
3 South Arizona plants (Erigeron piscaticus,        12-month petition finding.
 Astragalus hypoxylus, Amoreuxia gonzalezii) (from
 475 species petition).
5 Central Texas mussel species (3 from 475 species  12-month petition finding.
 petition).
14 parrots (foreign species)......................  12-month petition finding.
Berry Cave salamander \1\.........................  12-month petition finding.
Striped Newt \1\..................................  12-month petition finding.
Fisher--Northern Rocky Mountain Range \1\.........  12-month petition finding.
Mohave Ground Squirrel \1\........................  12-month petition finding.
Puerto Rico Harlequin Butterfly \3\...............  12-month petition finding.
Western gull-billed tern..........................  12-month petition finding.
Ozark chinquapin (Castanea pumila var. ozarkensis)  12-month petition finding.
 \4\.
HI yellow-faced bees..............................  12-month petition finding.
Giant Palouse earthworm...........................  12-month petition finding.
Whitebark pine....................................  12-month petition finding.

[[Page 12682]]

 
OK grass pink (Calopogon oklahomensis) \1\........  12-month petition finding.
Ashy storm-petrel \5\.............................  12-month petition finding.
Honduran emerald..................................  12-month petition finding.
Southeastern pop snowy plover and wintering pop.    90-day petition finding.
 of piping plover \1\.
Eagle Lake trout \1\..............................  90-day petition finding.
Smooth-billed ani \1\.............................  90-day petition finding.
32 Pacific Northwest mollusks species (snails and   90-day petition finding.
 slugs) \1\.
42 snail species (Nevada and Utah)................  90-day petition finding.
Peary caribou.....................................  90-day petition finding.
Plains bison......................................  90-day petition finding.
Spring Mountains checkerspot butterfly............  90-day petition finding.
Spring pygmy sunfish..............................  90-day petition finding.
Bay skipper.......................................  90-day petition finding.
Unsilvered fritillary.............................  90-day petition finding.
Texas kangaroo rat................................  90-day petition finding.
Spot-tailed earless lizard........................  90-day petition finding.
Eastern small-footed bat..........................  90-day petition finding.
Northern long-eared bat...........................  90-day petition finding.
Prairie chub......................................  90-day petition finding.
10 species of Great Basin butterfly...............  90-day petition finding.
6 sand dune (scarab) beetles......................  90-day petition finding.
Golden-winged warbler \4\.........................  90-day petition finding.
Sand-verbena moth.................................  90-day petition finding.
404 Southeast species.............................  90-day petition finding.
Franklin's bumble bee \4\.........................  90-day petition finding.
2 Idaho snowflies (straight snowfly and Idaho       90-day petition finding.
 snowfly) \4\.
American eel \4\..................................  90-day petition finding.
Gila monster (Utah population) \4\................  90-day petition finding.
Arapahoe snowfly \4\..............................  90-day petition finding.
Leona's little blue \4\...........................  90-day petition finding.
Aztec gilia \5\...................................  90-day petition finding.
White-tailed ptarmigan \5\........................  90-day petition finding.
San Bernardino flying squirrel \5\................  90-day petition finding.
Bicknell's thrush \5\.............................  90-day petition finding.
Chimpanzee........................................  90-day petition finding.
Sonoran talussnail \5\............................  90-day petition finding.
2 AZ Sky Island plants (Graptopetalum bartrami and  90-day petition finding.
 Pectis imberbis) \5\.
I'iwi \5\.........................................  90-day petition finding.
----------------------------------------------------------------------------------------------------------------
                                          High-Priority Listing Actions
----------------------------------------------------------------------------------------------------------------
19 Oahu candidate species \2\ (16 plants, 3         Proposed listing.
 damselflies) (15 with LPN = 2, 3 with LPN = 3, 1
 with LPN = 9).
19 Maui-Nui candidate species \2\ (16 plants, 3     Proposed listing.
 tree snails) (14 with LPN = 2, 2 with LPN = 3, 3
 with LPN = 8).
2 Arizona springsnails \2\ (Pyrgulopsis bernadina   Proposed listing.
 (LPN = 2), Pyrgulopsis trivialis (LPN = 2)).
Chupadera springsnail \2\ (Pyrgulopsis chupaderae   Proposed listing.
 (LPN = 2)).
8 Gulf Coast mussels (southern kidneyshell (LPN =   Proposed listing.
 2), round ebonyshell (LPN = 2), Alabama
 pearlshell (LPN = 2), southern sandshell (LPN =
 5), fuzzy pigtoe (LPN = 5), Choctaw bean (LPN =
 5), narrow pigtoe (LPN = 5), and tapered pigtoe
 (LPN = 11)) \4\.
Umtanum buckwheat (LPN = 2) and white bluffs        Proposed listing.
 bladderpod (LPN = 9) \4\.
Grotto sculpin (LPN = 2) \4\......................  Proposed listing.
2 Arkansas mussels (Neosho mucket (LPN = 2) and     Proposed listing.
 Rabbitsfoot (LPN = 9)) \4\.
Diamond darter (LPN = 2) \4\......................  Proposed listing.
Gunnison sage-grouse (LPN = 2) \4\................  Proposed listing.
Miami blue (LPN = 3) \3\..........................  Proposed listing.
4 Texas salamanders (Austin blind salamander (LPN   Proposed listing.
 = 2), Salado salamander (LPN = 2), Georgetown
 salamander (LPN = 8), Jollyville Plateau (LPN =
 8)) \3\.
5 SW aquatics (Gonzales Spring Snail (LPN = 2),     Proposed listing.
 Diamond Y springsnail (LPN = 2), Phantom
 springsnail (LPN = 2), Phantom Cave snail (LPN =
 2), Diminutive amphipod (LPN = 2)) \3\.
2 Texas plants (Texas golden gladecress             Proposed listing.
 (Leavenworthia texana) (LPN = 2), Neches River
 rose-mallow (Hibiscus dasycalyx) (LPN = 2)) \3\.
FL bonneted bat (LPN = 2) \3\.....................  Proposed listing.
21 Big Island (HI) species \5\ (includes 8          Proposed listing.
 candidate species--5 plants and 3 animals; 4 with
 LPN = 2, 1 with LPN = 3, 1 with LPN = 4, 2 with
 LPN = 8).
12 Puget Sound prairie species (9 subspecies of     Proposed listing.
 pocket gopher (Thomomys mazama ssp.) (LPN = 3),
 streaked horned lark (LPN = 3), Taylor's
 checkerspot (LPN = 3), Mardon skipper (LPN = 8))
 \3\.
2 TN River mussels (fluted kidneyshell (LPN = 2),   Proposed listing.
 slabside pearlymussel (LPN = 2)) \5\.
Jemez Mountain salamander (LPN = 2) \5\...........  Proposed listing.
----------------------------------------------------------------------------------------------------------------
\1\ Funds for listing actions for these species were provided in previous FYs.
\2\ Although funds for these high-priority listing actions were provided in FY 2008 or 2009, due to the
  complexity of these actions and competing priorities, these actions are still being developed.

[[Page 12683]]

 
\3\ Partially funded with FY 2010 funds and FY 2011 funds.
\4\ Funded with FY 2010 funds.
\5\ Funded with FY 2011 funds.

    We have endeavored to make our listing actions as efficient and 
timely as possible, given the requirements of the relevant law and 
regulations, and constraints relating to workload and personnel. We are 
continually considering ways to streamline processes or achieve 
economies of scale, such as by batching related actions together. Given 
our limited budget for implementing section 4 of the Act, these actions 
described above collectively constitute expeditious progress.
    The Mt. Charleston blue butterfly will be added to the list of 
candidate species upon publication of this 12-month finding. We will 
continue to monitor the status of this species as new information 
becomes available. This review will determine if a change in status is 
warranted, including the need to make prompt use of emergency listing 
procedures.
    We intend that any proposed listing action for the Mt. Charleston 
blue butterfly will be as accurate as possible. Therefore, we will 
continue to accept additional information and comments from all 
concerned governmental agencies, the scientific community, industry, or 
any other interested party concerning this finding.

References Cited

    A complete list of all references cited is available on request 
from the Nevada Fish and Wildlife Office (see ADDRESSES).

Authors

    The primary authors of this document are the staff members of the 
U.S. Fish and Wildlife Service, Nevada Fish and Wildlife Office (see 
ADDRESSES).

Authority

    The authority for this action is section 4 of the Endangered 
Species Act of 1973, as amended (16 U.S.C. 1531 et seq.).

    Dated: February 11, 2011.
 Rowan W. Gould,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2011-4884 Filed 3-7-11; 8:45 am]
BILLING CODE 4310-55-P