Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition To List the Prince of Wales Flying Squirrel as Threatened or Endangered, 52301-52308 [2012-21232]

Agencies

• Fish and Wildlife Service
• DEPARTMENT OF THE INTERIOR

[Federal Register Volume 77, Number 168 (Wednesday, August 29, 2012)]
[Proposed Rules]
[Pages 52301-52308]
From the Federal Register Online via the Government Printing Office [www.gpo.gov]
[FR Doc No: 2012-21232]



[[Page 52301]]

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DEPARTMENT OF THE INTERIOR

Fish and Wildlife Service

50 CFR Part 17

[Docket No. FWS-R7-ES-2012-0062; 4500030113]


Endangered and Threatened Wildlife and Plants; 90-Day Finding on 
a Petition To List the Prince of Wales Flying Squirrel as Threatened or 
Endangered

AGENCY: Fish and Wildlife Service, Interior.

ACTION: Notice of 90-day petition finding.

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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a 
90-day finding on a petition to list the Prince of Wales flying 
squirrel (Glaucomys sabrinus griseifrons) as an endangered or 
threatened species under the Endangered Species Act of 1973, as amended 
(Act), and to designate critical habitat. Based on our review, we find 
that the petition does not present substantial information indicating 
that listing this subspecies may be warranted. Therefore, we are not 
initiating a status review in response to this petition. However, we 
ask the public to submit to us any new information that becomes 
available concerning the status of, or threats to, the Prince of Wales 
flying squirrel or its habitat at any time.

DATES: The finding announced in this document was made on August 29, 
2012.

ADDRESSES: This finding is available on the Internet at https://www.regulations.gov at Docket Number FWS-R7-ES-2012-0062. 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, Juneau Fish and Wildlife Field Office, 3000 
Vintage Blvd., Suite 201, Juneau, Alaska 99801. Please submit any new 
information, materials, comments, or questions concerning this finding 
to the above address.

FOR FURTHER INFORMATION CONTACT: Bill Hanson, Field Office Supervisor, 
of the Juneau Fish and Wildlife Field Office (see ADDRESSES), by 
telephone 907-780-1160, or by facsimile to 907-586-7099. If you use a 
telecommunications device for the deaf (TDD), please call the Federal 
Information Relay Service (FIRS) at 800-877-8339.

SUPPLEMENTARY INFORMATION: 

Background

    Section 4(b)(3)(A) of the Act (16 U.S.C. 1531 et seq.) requires 
that we make a finding on whether a petition to list, delist, or 
reclassify a species presents substantial scientific or commercial 
information indicating that the petitioned action may be warranted. We 
are to base this finding on information provided in the petition, 
supporting information submitted with the petition, and information 
otherwise available in our files. To the maximum extent practicable, we 
are to make this finding within 90 days of our receipt of the petition, 
and publish our notice of the finding promptly in the Federal Register.
    Our standard for substantial scientific or commercial information 
within the Code of Federal Regulations (CFR) with regard to a 90-day 
petition finding is ``that amount of information that would lead a 
reasonable person to believe that the measure proposed in the petition 
may be warranted'' (50 CFR 424.14(b)). If we find that substantial 
scientific or commercial information was presented or is available in 
our files, we are required to promptly conduct a species status review, 
which we subsequently summarize in our 12-month finding.

Petition History

    On October 6, 2011, we received a petition, dated September 30, 
2011, from Mark N. Salvo, WildEarth Guardians, requesting that the 
Prince of Wales flying squirrel be listed as an endangered or 
threatened species and that critical habitat be designated under the 
Act. The petition clearly identified itself as such and included the 
requisite identification information for the petitioner(s), as required 
by 50 CFR 424.14(a). In a December 20, 2011, letter to petitioner(s), 
we responded that we reviewed the information presented in the petition 
and determined that issuing an emergency regulation temporarily listing 
the species under section 4(b)(7) of the Act was not warranted. We also 
stated that when budget and workload enabled us to direct resources to 
the petition, we would make an initial finding on whether the petition 
presented substantial information indicating that the petitioned action 
may be warranted. We received funding in January 2012. This finding 
addresses the petition.

Previous Federal Action(s)

    There are no previous Federal actions concerning the status of the 
Prince of Wales Flying squirrel under the Act.

Species Information

    The Prince of Wales (POW) flying squirrel (Glaucomys sabrinus 
griseifrons) is a small (4.6 ounces [130 grams]), nocturnal, 
nonhibernating, arboreal rodent that is endemic to the southern part of 
the Alexander Archipelago in Southeast Alaska. It occurs on at least 11 
islands, including POW (1,428,768 acres [ac] (578,202 hectares [ha])), 
Kosciusko (119,251 ac [48,259 ha]), Heceta (46,742 ac [18,916 ha]), 
Suemez (37,560 ac [15,200 ha]), Tuxekan (21,061 ac [8,523 ha]), Dall 
(162,766 ac [65,869 ha]), Orr (5,842 ac [2,364 ha]), El Capitan (1,562 
ac [632 ha]) islands and three of the Barrier Islands (less than 1,236 
ac [500 ha] total) (Demboski et al. 1998, p. 1774; Bidlack and Cook 
2001, p. 284; Bidlack and Cook 2002, p. 248; MacDonald and Cook 2007, 
pp. 21-22, p. 172). All of these islands are part of a larger group of 
islands often referred to as the POW Complex (2,305,058 ac [932,824 
ha]), but it is unknown whether the POW flying squirrel occurs on many 
of the smaller islands within the POW Complex. The only other 
subspecies (G. s. zaphaeus) of the northern flying squirrel that occurs 
in southeastern Alaska is restricted to the mainland and four adjacent 
islands (Mitkof, Wrangell, Etolin, and Revillagigedo islands) (Bidlack 
and Cook 2001, p. 286).
    The distinctness of the POW flying squirrel as a subspecies is well 
documented. Howell (1934, p. 64) proposed the original subspecific 
designation based on the darker pelage coloration and whiter underparts 
of only two specimens from POW Island compared to those of the mainland 
subspecies (G. s. zaphaeus). In recent years, mitochondrial DNA and 
microsatellite data have confirmed that the POW flying squirrel is 
genetically distinct (Demboski et al. 1998, p. 1773; Bidlack and Cook 
2001, pp. 286-288; Bidlack and Cook 2002, pp. 254-255). Base pair 
changes seen in mitochondrial sequences (Demboski et al. 1998, p. 1774; 
Bidlack and Cook 2001, p. 285), unique microsatellite alleles, and 
distinctive microsatellite frequencies (Bidlack and Cook 2002, pp. 250-
252) in the POW Complex all indicate differentiation from the mainland 
squirrel populations. Therefore, we accept the characterization of the 
Prince of Wales flying squirrel as a subspecies of the northern flying 
squirrel.
    There is little information about the historical range of the POW 
flying squirrel, but genetic studies indicate that flying squirrels 
probably colonized the archipelago after the last glacial maximum 
during the Holocene (Bidlack

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and Cook 2001, p. 286; Bidlack and Cook 2002, pp. 253-254). These same 
genetic data suggest that POW flying squirrels have been isolated for 
enough time to observe a reduction in genetic variation (due to drift 
in smaller populations) and to accumulate and fix new mutations in the 
island populations (Bidlack and Cook 2002, p. 255). There is no 
evidence to support or refute the possibility that the historical range 
of the POW flying squirrel has changed since colonization and 
subspeciation occurred.
    There is no information regarding population size or trend of the 
POW flying squirrel within any parts of its range. During the most 
recent status review of this insular subspecies, the International 
Union for the Conservation of Nature (Hafner et al. 1998, pp. 37-39) 
considered it to be ``threatened'' and NatureServe (2012 [online]) 
categorized it as ``imperiled,'' but both of these designations were 
predicated on the critical assumption that the POW flying squirrel 
requires old-growth forest to survive and reproduce successfully. While 
several studies investigating habitat relationships of the northern 
flying squirrel in the Pacific Northwest have concluded that optimal 
conditions for this species occur in old-growth forests (Carey 1995, p. 
654; Carey et al. 1999, p. 41; and others, but see Rosenberg and 
Anthony 1992, p. 163), this does not appear to be the case for the POW 
flying squirrel in the coastal, temperate rainforests of Southeast 
Alaska (Smith et al. 2005, pp. 695-696).
    Densities of the POW flying squirrel are among the highest flying 
squirrel densities recorded in North America (Smith 2007, p. 863). This 
subspecies occupies a variety of forested habitats with densities often 
increasing with forest complexity. Spring densities (number/ac) average 
0.7 squirrels/ac (1.8 squirrels/ha) in upland old-growth forests of 
Sitka spruce (Picea sitchensis) and western hemlock (Tsuga 
heterophylla) and 0.5 squirrels/ac (1.2 squirrels/ha) in peatland-
mixed-conifer forests (Smith and Nichols 2003, p. 1049). In autumn when 
dispersing juveniles are present, corresponding densities are 1.3 
squirrels/ac (3.2 squirrels/ha) and 0.7 squirrels/ac (1.8 squirrels/
ha), respectively (Smith and Nichols 2003, p. 1049). Overall, squirrel 
densities between the two habitat types do not differ significantly, 
but there is a significant habitat-by-season interaction with mean 
squirrel density in autumn higher in spruce-hemlock forests compared to 
peatland-mixed-conifer forests (Smith and Nichols 2003, p. 1049). There 
are no density estimates of the POW flying squirrel in managed forests, 
such as young or second growth stands.
    Specific habitat correlates of density and use of the POW flying 
squirrel vary by season, forest type, and scale (Smith et al. 2004, pp. 
667-668), but squirrel density and habitat use are most likely linked 
to resource availability at the scale of individual home ranges (Smith 
et al. 2005, p. 695). Smith et al. (2004, p. 667) found that 13 of 26 
vegetative and structural habitat elements were statistically 
significant in explaining the variation in density and habitat use of 
the POW flying squirrel in two seasons (spring, autumn) and two old-
growth forest types (upland old-growth, peatland-mixed-conifer). 
However, further analysis indicated that habitat use of the POW flying 
squirrel was best predicted by single habitat variables, as opposed to 
multivariate factors (Smith et al. 2005, pp. 694-695).
    To sum, densities of large trees (greater than 29 inches [in] (74 
centimeters [cm]) diameter at breast height [dbh]) and understory cover 
of blueberry and huckleberry shrubs (Vaccinium species; hereafter 
Vaccinium) explain much of the variation in microhabitat use by POW 
flying squirrels; as large tree density and Vaccinium cover increased, 
capture rates of squirrels also increased (Smith et al. 2004, p. 667; 
Smith et al. 2005, p. 689). This result differs from patterns of 
habitat use reported for flying squirrel populations in the Pacific 
Northwest, which clearly prefer complex, multi factorial habitat 
conditions that are characteristic of old-growth forests (Carey et al. 
1999, pp. 24-25, 39-40). Smith et al. (2005, p. 696) proposed that the 
diet of the POW flying squirrel and the community structure of arboreal 
rodents (although not mutually exclusive), especially squirrels (Family 
Sciuridae), may be sufficiently different than those in the Pacific 
Northwest to facilitate a more general lifestyle.
    Despite the high number of endemic species in Southeast Alaska, the 
small mammal community is relatively low in numbers or variety of 
species compared to the coniferous forests of Washington and Oregon 
where at least 57 native terrestrial mammal species have been observed 
(Carey 1995, p. 653; Smith and Nichols 2003, p. 1054; MacDonald and 
Cook 2007, pp. 15-17). Only 15 native mammal species have been 
documented on POW Island (MacDonald and Cook 2007, p. 142), and the POW 
flying squirrel is the only arboreal or forest-floor squirrel 
(MacDonald and Cook 2007 p. 177). Across most of the range of the 
northern flying squirrel, the American red squirrel (Tamiasciurus 
hudsonicus) occurs, and the two species directly compete for food and 
habitat resources. On POW Island, however, red squirrels are not 
present, providing the POW flying squirrel with almost exclusive access 
to many resources important to its life cycle (Smith and Nichols 2003, 
p. 1054; MacDonald and Cook 2007, pp. 25-27). Undoubtedly, this 
competitive release from interspecific competition further 
distinguishes the flying squirrels of Southeast Alaska from those in 
the Pacific Northwest.
    In most parts of its range, the northern flying squirrel feeds on 
truffles and plays an important role in dispersing their spores in 
coniferous forest ecosystems (Weigl 2007, p. 900). In contrast, the POW 
flying squirrel relies less on truffles and feeds on a greater 
diversity of food items than other subspecies of northern flying 
squirrel (Maser et al. 1986, p. 2087; Carey et al. 1999, p. 46; Pyare 
et al. 2002, p. 100; Flaherty et al. 2010, p. 85). Stable isotope and 
fecal analyses show that the main dietary items of POW flying squirrels 
were conifer seeds, lichens, and fungi, all of which are more abundant 
in old-growth than in young-growth forests (Flaherty et al. 2010, p. 
85). Truffles appear to be a moderately important component of the POW 
flying squirrel diet with spores identified in about 50 percent of 
fecal samples (Pyare et al. 2002, p. 100). However, Elaphomyces, the 
most common fungus on POW Island, has minimal nutritional value for 
squirrels (Flaherty et al. 2010, pp. 86-87). Overall, the POW flying 
squirrel has a far less specialized diet than the northern flying 
squirrels of the Pacific Northwest. This likely allows them to utilize 
a greater diversity of forested habitats, especially when coupled with 
the absence of competition with the red squirrel.
    The northern flying squirrel uses dens for shelter and to carry out 
important ecological and life history functions such as avoiding 
predators, caching food, thermoregulating, and reproducing. Flying 
squirrels use multiple dens within their home range, or core den area, 
and, therefore, the availability of suitable den sites on the landscape 
is strongly linked to the persistence of local squirrel populations. 
Pyare et al. (2010, p. 891) found that POW flying squirrels den in 
cavities in live trees (42 percent) or snags (51 percent), rarely 
constructing their own nests (2 percent) or using the ground (3 
percent). Positive correlates of den trees used by POW flying squirrels 
include diameter at breast height (dbh) for both live trees (mean dbh = 
40 in [101 cm]) and snags (mean dbh = 29 in

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[73 cm]), number of conks (hard, shelf-like structure of wood-decaying 
fungi found on stumps, logs, or trees) and bole entries (openings in 
the trunk or main stem of a tree) in live trees, and decay class for 
snags (Pyare et al. 2010, p. 892).
    In their study, the authors found that squirrels used 3.5-7.1 dens/
month and moved 195-711 yards (yd [178-650 meters (m)]) between dens 
(Pyare et al. 2010, p. 891). Compared to northern flying squirrels in 
other parts of their range, adult POW flying squirrels occupy smaller 
core denning areas, yet use more den trees per month (Pyare et al. 
2010, p. 891). This finding coupled with the nearly exclusive use of 
cavities for denning (93 percent) suggests that suitable cavities were 
readily available to squirrels despite the intensely managed landscape 
in which the study was conducted (Pyare et al. 2010, p. 893). At a 
broader scale, POW flying squirrels den in larger forested habitat 
patches, but with greater amounts of edge, than what was available on 
the landscape (Pyare et al. 2010, p. 893). Results of this study 
suggest that despite the need for larger trees for denning, the POW 
flying squirrel is not limited by availability or suitability of 
cavities or den sites, even in the small and insular habitat fragments 
in their study area, and is capable of moving large distances between 
den sites.
    Although the POW flying squirrel occupies a variety of forested 
habitats to meet its life-history needs, the persistence of squirrels, 
especially in a managed landscape, relies heavily on their ability to 
disperse to suitable habitats. Flying squirrels can glide from one tree 
to another or can walk or run on the ground, but Flaherty et al. 2010, 
p. 1051) speculated that ground travel was more energetically costly 
than gliding. High forest canopies and relatively open under- and mid-
story layers provide squirrels with high launch points and unobstructed 
gliding space, both of which allow for longer glides and less energy 
expenditure (Flaherty et al. 2008, p. 1051). Vernes (2001 [in Flaherty 
et al. 2008, p. 1057]) determined that squirrels will glide across a 
distance that is twice as long as the height of their launch; mean tree 
height of Sitka spruce and western hemlock in Southeast Alaska is 41.2 
yd (37.7 m).
    Flaherty et al. (2008, pp. 1055-1057) estimated the perceptual 
range, the distance at which an animal can perceive a particular 
habitat or landscape feature (Lima and Zollner 1996 [in Flaherty et al. 
2008, p. 1051]), of a POW flying squirrel to be 109-164 yd (100-150 m) 
in clearcuts and 27-55 yd (25-50 m) in second-growth forests, both far 
smaller than the average width of managed stands on POW Island (about 
394 yd [360 m]). The authors reported, however, that the ability of 
individual squirrels to select and orient themselves to the shortest 
distance towards a suitable habitat patch is most influenced by factors 
affecting sense of smell capabilities (e.g., precipitation, wind 
speed), not visual or auditory cues (Flaherty et al. 2008, p. 1055).
    While there is presumably a fragmentation threshold in which flying 
squirrel dispersal would cease (or be drastically reduced), there is no 
information available that quantifies this threshold, and there is no 
evidence that this threshold has been reached on the highly managed 
forested landscapes within the POW Complex. Bidlack and Cook (2002, p. 
256) found that there is contemporary gene flow among squirrel 
populations in the POW Complex, although that flow is primarily 
affected by distance between populations, and Pyare et al. (2010, p. 
891) estimated very large core den areas and movements of juvenile POW 
flying squirrels across a highly fragmented landscape, suggesting that 
dispersal is occurring and is not a limiting factor to population 
persistence.
    The northern flying squirrel has several life-history traits 
characteristic of a K-selected species (Smith 2007, p. 862), which 
produce few offspring and live in stable environments. It is relatively 
long-lived (greater than 7 years), produces small litters (usually 2-3 
young) after a long gestation period (37-42 days), and exhibits 
density-dependent population growth (Fryxell et al. 1998 [in Smith 
2007, p. 862; Lehmkuhl et al. 2006, p. 589). Consequently, annual 
survival rates are expected to be high. Accordingly, Smith and Nichols 
(2003, pp. 1050-1052) estimated minimum survival on POW Island to be 
16.7-65.7 percent in summer and 43.9-60.4 percent in winter with mean 
recapture probability of 0.33 (range = 0.30-0.39; p. 1049). In the same 
study, there was weak evidence suggesting that productivity was higher 
in upland-old-growth forest than in peatland-mixed-conifer forest. The 
number of reproductive females captured was greater in upland-old-
growth (3.9/trapping grid versus 2.1/trapping grid in peatland-mixed-
conifer), but there was no difference between the percentage of 
reproductive females captured in either habitat (75.5 percent in 
upland-old-growth, 75.9 percent in peatland-mixed-conifer (Smith and 
Nichols 2003, p. 1050)).

Evaluation of Information for This Finding

    Section 4 of the Act (16 U.S.C. 1533) and its implementing 
regulations at 50 CFR 424 set forth the procedures for adding a species 
to, or removing a species from, the Federal Lists of Endangered and 
Threatened Wildlife and Plants. A species may be determined to be an 
endangered or threatened species due to one or more of the five factors 
described in section 4(a)(1) of the Act:
    (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.
    In considering what factors might constitute threats, we must look 
beyond the mere exposure of the species to the factor to determine 
whether the species responds to the factor in a way that causes actual 
impacts to the species. If there is exposure to a factor, but no 
response, or only a positive response, that factor is not a threat. If 
there is exposure and the species responds negatively, the factor may 
be a threat and we then attempt to determine how significant a threat 
it is. If the threat is significant enough that it may drive or 
contribute to the risk of extinction of the species such that the 
species may warrant listing as a threatened or endangered species as 
those terms are defined by the Act, this does not necessarily require 
empirical proof of a threat. The combination of exposure and some 
corroborating evidence of how the species is likely impacted could 
suffice. The mere identification of factors that could impact a species 
negatively may not be sufficient to compel a finding that listing may 
be warranted. The information must include evidence sufficient to 
suggest that these factors may be operative threats that act on the 
species to the point that the species may meet the definition of a 
threatened or endangered species under the Act.
    In making this 90-day finding, we evaluated whether or not 
information regarding the threats to the POW flying squirrel, as 
presented in the petition and other information available in our files, 
is substantial, thereby indicating that the petitioned action may be 
warranted. Our evaluation of this information is presented below.

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A. The Present or Threatened Destruction, Modification, or Curtailment 
of Its Habitat or Range

Information Provided in the Petition
    According to the petitioner, the POW flying squirrel is an island 
endemic species that occupies forest habitats and, therefore, is 
vulnerable to negative impacts of logging and associated habitat 
fragmentation. There is a long history of logging in Southeast Alaska, 
especially on POW Island where roughly 39 percent of the old-growth 
forest has been harvested. This has resulted in a complex matrix of 
forest stands of varying age, muskeg (bog, marsh, or peatland; an area 
of mosses, sedges, and open growth of scrubby trees), less productive 
forests, and the presence of roads (WildEarth Guardians 2011, p. 2). 
The petitioner raises concern that the composition and spatial 
configuration of remaining forests within the range of the POW flying 
squirrel is not sufficient for the squirrel to meet its life-history 
needs and, therefore, to persist into the future.
    There are two pinchpoints, or narrow land corridors connecting 
larger areas of old-growth forest, on POW Island that are currently not 
protected and, therefore, are susceptible to future development. The 
Neck Lake and Sulzer Portage areas are nearly surrounded by private 
lands that have previously been subject to intense logging. These areas 
are connected to fragments of old-growth habitat intermixed with water, 
rugged terrain, and logged stands. All of these features are implicated 
by the petitioner in preventing movement of squirrels across the 
pinchpoints. The petitioner suggests that if these two pinchpoints are 
developed and the forest is removed, flying squirrel populations on 
either side of the pinchpoints may become isolated from one another. 
Although there is an existing series of old-growth reserves in Tongass 
National Forest lands on POW Island, flying squirrels may have a 
difficult time moving among these reserves especially if additional 
logging occurs as is planned within the next 100 years.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    The petitioner raises three primary concerns related to the 
destruction, modification, or curtailment of habitat or range of the 
POW flying squirrel, none of which were supported by the information in 
our files or the petition itself. First, the petitioner suggests that 
current and future forest composition within the POW Complex is not 
adequate for the persistence of the POW flying squirrel, assuming that 
this subspecies is an old-growth obligate. Second, the petitioner 
identified lack of connectivity among forest habitat patches and 
habitat fragmentation as factors reducing the population viability and 
long-term persistence of POW flying squirrels. Third, the petitioner 
raises concern about possible future development and additional logging 
within the range of the POW flying squirrel. We do not find substantial 
information supporting any of these assertions related to this threat.
    There are many definitions for old-growth forest. Generally, we 
consider old-growth forests to be in a late successional stage of 
forest development with both vertical and horizontal structural 
diversity including live trees and snags of a minimum number and size, 
canopy conditions with multiple layers, and logs and large woody debris 
(often on the forest floor). These forests are complex and involve 
several habitat variables. Species that rely on old-growth forests 
typically require habitat features of similar complexity.
    The POW flying squirrel occupies a diversity of forested habitats 
within its range. Although squirrel densities are slightly higher in 
productive, upland old-growth forests than in lower productive, 
peatland-mixed-conifer forests in Southeast Alaska (Smith and Nichols 
2003, p. 1049), two habitat features alone--density of large trees and 
understory cover of Vaccinium--explain much of the variation in habitat 
use of the POW flying squirrel (Smith et al. 2004, pp. 693-694). Smith 
et al. (2005) modeled habitat use of the POW flying squirrel and 
determined that complex models containing multiple variables performed 
poorly compared to simple models of individual habitat variables (i.e., 
looking at one habitat characteristic at a time). The lack of 
complexity of habitat conditions used by the POW flying squirrel 
suggests that this species is not an old-growth obligate species even 
though squirrel densities are often higher in old-growth forests. 
Therefore, unlike flying squirrels in other coniferous forests, 
especially in the Pacific Northwest (Carey et al. 1999, pp. 24-25, 39-
40), the information suggests that the POW flying squirrel is not an 
old-growth obligate species but uses a wider range of habitat types 
successfully. Furthermore, densities of the POW flying squirrel in a 
variety of forested habitats are among the highest flying squirrel 
densities recorded in North America (Smith 2007, p. 863). Based on the 
information in our files, any population projections of the POW flying 
squirrel based on the assumption that they depend on old growth and any 
loss of old growth equates to a loss in POW flying squirrels are not 
valid.
    We acknowledge that population density is not necessarily a 
reliable indicator of habitat quality. Smith and Nichols (2003, p. 
1052) captured more reproductive females in upland-old-growth forest 
(3.9/trapping grid) compared to peatland-mixed-conifer forest (2.1/
trapping grid in peatland-mixed-conifer). Based on this finding, Smith 
and Person (2007, p. 632) speculated that flying squirrels occupying 
peatland-mixed-conifer forests in some years represent population sinks 
that are sustained by immigration. However, Smith and Nichols (2003, p. 
1052) reported no difference between the percentage of reproductive 
females captured in either habitat (75.5 percent in upland-old-growth, 
75.9 percent in peatland-mixed-conifer), and, therefore, it is 
difficult to interpret the results of the study as they relate to 
identifying population sources, sinks, and habitat selection of the POW 
flying squirrel.
    There is insufficient and mixed evidence that fragmentation and 
lack of connectivity influences habitat use of POW flying squirrels. In 
a heavily managed landscape, POW flying squirrels chose to den in areas 
with larger habitat patches, but also greater absolute amounts of edge 
than what was available across the landscape (Pyare et al. 2010, p. 
894). Similarly, POW flying squirrels were more likely to be captured 
in traps on the forest edge compared to forest interior (Smith et al. 
2004, p. 666). Pyare et al. (2010) noted that radio-collared squirrels 
moved large distances to find suitable den sites (p. 891), traveling 
through linear old-growth fragments with a high edge-to-area ratio at 
rates nearly equivalent to those in more interior old-growth forest (p. 
894). These findings indicate that squirrel habitat use is not 
negatively correlated with forest edge or current levels of 
fragmentation on the POW Complex. Furthermore, despite the intensive 
and extensive logging within this area over the last 50 years, there is 
contemporary gene flow among populations of POW flying squirrels 
(Bidlack and Cook 2002, pp. 250-252), suggesting that there are 
currently few connectivity barriers within the range of this 
subspecies.
    The Tongass Land and Resource Management Plan (2008, p. 2-4; 
hereafter, Tongass Land Management Plan; TLMP), which outlines 
management of 80 percent of the lands in Southeast Alaska, includes a 
conservation strategy aimed to maintain

[[Page 52305]]

a forest-wide system of old-growth and other forest habitats to sustain 
old-growth associated species and resources. The strategy includes a 
series of small (less than 1,606 ac [650 ha]), medium (about 10,008 ac 
[4050 ha]), and large reserves (at least 40,031 ac [16,200 ha]), 
nondeveloped areas (e.g., Wilderness and Research Natural areas), and 
beach, estuary, and riparian corridors (TLMP Final Environmental Impact 
Statement 2008, p. D-6). Within the POW Complex, there are 95 reserves 
consisting of 65 small, 24 medium, and 4 large reserves totaling 
325,081 ac (131,556 ha) and 4 designated Wilderness Areas protecting 
229,630 ac (92,928 ha) on Federal land. Across all Federal and non-
Federal lands within the POW Complex, approximately half (44%) of the 
land is either legally (325,398 ac [131,684 ha] or administratively 
(691,102 ac [279,679 ha] protected and the remainder is or may be 
developed (1,288,563 ac [521,463 ha]).
    Although the efficacy of many aspects of the conservation strategy 
remains untested, the POW flying squirrel was a design species in 
developing the criteria for habitat conservation areas, specifically 
the small reserves (Julin 1997, p. 19). Smith and Person (2007, p. 627) 
assessed the size and composition of these small reserves by modeling 
population viability of the POW flying squirrel in two habitat types 
(upland-old-growth, peatland-mixed-conifer). The primary purpose of 
this modeling exercise was to evaluate the potential of only individual 
small habitat reserves for flying squirrel population viability. The 
authors did not include medium and large reserves or corridors in their 
analysis. Furthermore, they assumed no immigration or emigration among 
small reserves. However, based on POW flying squirrel movements (Pyare 
et al. 2010, p. 891) and contemporary gene flow (Bidlack and Cook 2002, 
p. 256), this was not a valid assumption. Despite these limitations, 
modeled estimates of time to extinction of POW flying squirrel were 
high, ranging from 118 to 507 years (or approximately 12 to 50 
generations) depending on habitat type and percent of upland-old-growth 
within the habitat patch (Smith and Person 2007, pp. 630-631) and 
intrinsic rates of population growth indicated stable or increasing 
populations (greater than zero) regardless of habitat type (p. 629). 
Therefore, in the absence of trend information or an explicit field-
based test of the assumptions or reserve criteria and because the model 
assumptions were very conservative (i.e., only small reserves 
available, no dispersal), the information available suggests that the 
conservation strategy, if implemented properly, will provide sufficient 
suitable habitat for population viability, and for connectivity between 
and among forest reserves and habitat fragments in the POW Complex. 
Petitioners did not provide any information to change this analysis or 
refute the conservation strategy.
    Although the conservation strategy does not extend to non-Tongass 
lands, the majority of land in the POW Complex (~97 percent) is part of 
the Tongass National Forest and, therefore, is subject to the standards 
and guidelines described in the plan. The petition raises concern that 
the non-Federal lands on POW Island are not protected currently and, 
therefore, are available for development; other than the assertion by 
the petitioners, there is no information that suggests that this lack 
of protection or the non-Federal land ownership suffice as substantial 
information suggesting a threat to the POW flying squirrel, especially 
given the other land protections and management prescriptions on 
Federal lands within the range of this subspecies and the overall 
amount of existing forested land within the range of this subspecies 
(722,010 ha; Table 2 in petition, p. 20).
    The petitioner states that a flawed assumption of the Tongass Land 
Management Plan is that second-growth forests will provide lesser but 
sufficient quality habitat for the POW flying squirrel (petition, p. 
19). This statement was uncited, and we were unable to find reference 
to it within the management plan itself. Regardless, we did not find 
any information evaluating the use of second-growth forested stands 
specifically by POW flying squirrels, but Flaherty et al. (2010, p. 87) 
reported that low availability of some food items in second-growth 
forests may constrain dispersal of squirrels across these habitats. We 
agree that movement of POW flying squirrels between and among forest 
patches on the landscape is critical to their persistence, but 
squirrels appear to be dispersing successfully based on radio-marked 
individuals (Pyare et al. 2010, p. 891) and contemporary gene flow 
among populations in the POW Complex (Bidlack and Cook 2002, pp. 250-
252). Furthermore, density and demography of northern flying squirrels 
in young and old-growth forests of the Pacific Northwest were similar 
(Rosenberg and Anthony 1992, p. 163; Carey 1995, p. 654; Lehmkuhl et 
al. 2006, p. 594).
    In summary, we found that the information provided in the petition, 
as well as other information in our files, does not suggest that the 
destruction, modification, or curtailment of habitat or range of the 
POW flying squirrel may be a threat to the subspecies because it is a 
habitat opportunist, using a variety of forested habitats, does not 
avoid forest edges, is apparently dispersing successfully across the 
current landscape, and is presumably benefiting from the forest reserve 
system, which provides considerable amounts of forested habitat 
throughout its range. We conclude that the information provided in the 
petition describing this potential threat was inconsistent with the 
published literature and available reports in our files.

B. Overutilization for Commercial, Recreational, Scientific, or 
Educational Purposes.

Information Provided in the Petition
    The petitioner raises concern about impacts of hunting on POW 
flying squirrel populations, especially given some of the K-selected 
life-history traits of this subspecies and the presumed small 
population size.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    The State of Alaska does not regulate or require reporting of take 
of POW flying squirrels. Additionally, we are not aware of targeted 
hunting effort of squirrels within the POW Complex, as suggested in the 
petition. Although POW flying squirrels may be taken occasionally by 
recreational or subsistence hunters, we do not have any information to 
suggest that hunting pressure on squirrels could be having a 
population-level impact within the POW Complex. Given their small size 
and nocturnal habits, it is unlikely that flying squirrels are sought 
by hunters for meat or fur, and we are not aware of any cultural 
significance of the flying squirrel to First Nations in Southeast 
Alaska.
    In summary, we found that the information provided in the petition, 
as well as other information in our files, does not present substantial 
scientific or commercial information indicating that overutilization 
for commercial, recreational, scientific, or educational purposes is a 
threat to the POW flying squirrel. Further, we are not aware of any 
other potential threats to the POW flying squirrel as a result of 
recreational or subsistence hunters within the POW Complex.

[[Page 52306]]

C. Disease or Predation.

Information Provided in the Petition
    The petitioner presents information to suggest that habitat 
destruction and fragmentation may result in increased predation on the 
POW flying squirrel. Reduction of canopy cover reduces protection of 
the POW flying squirrel when gliding for movement and may force 
individuals to resort to travel on the ground, increasing their 
exposure to predators. The petitioner identifies several potential 
nonnative predators including the raccoon (Procyon lotor), American 
marten (Martes americana), and feral cats and dogs.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    POW flying squirrels do not avoid natural or anthropogenic forest 
edges; in fact, Pyare et al. (2010, p. 894) found that they choose to 
den in habitat patches with greater absolute amounts of edge than what 
was available on the landscape and Smith et al. (2004, p. 666) reported 
greater capture rates of squirrels on the forest edge than in interior 
forest. Therefore, we did not find evidence that squirrels are avoiding 
forest edges, suggesting that neither predation risk is driving 
squirrel behavior nor is predation increased due to greater amounts of 
forest edge that may result from habitat fragmentation.
    Raccoons and marten have been introduced to some islands within the 
POW Complex, but neither appears to be having population-level impacts 
on the POW flying squirrel. In 1941, eight raccoons were introduced to 
a small island in El Capitan Passage on the west coast of POW Island. 
The transplant was apparently successful with occasional sightings of 
raccoons on POW Island as recently as 2001 (Paul 2009, p. 110). 
However, this population of raccoons is small and localized, and it is 
unlikely to be having a population-level impact on POW flying squirrels 
on the POW Complex. In 1934, ten marten were introduced to POW Island 
for fur trapping opportunities. This species is now well-established in 
the area; from 2001 to 2006, trappers reported 323-1,026 marten taken 
annually on POW Island (Paul 2009, pp. 104-105). However, Flynn et al. 
(2004, p. 23) estimated that POW flying squirrel was a small proportion 
(5-9 percent varying by year) of the diet of marten on POW Island, 
where they feed more commonly on salmon, voles, mice, and berries. The 
petitioner did not provide, and we have no evidence in our files, 
indicating that predation from feral cats or dogs is occurring. The 
barred owl (Strix varia) is a new inhabitant of Southeast Alaska, 
including the POW Complex (Kissling and Lewis 2009, p. 80). This 
species likely preys on the POW flying squirrel, but we do not have any 
quantitative or qualitative information regarding the diet of the 
barred owl in this area and, therefore, cannot evaluate any potential 
impacts on POW flying squirrel populations. However, we are not aware 
of any evidence suggesting that barred owls are having a population 
level impact.
    We did not find any information describing existing or potential 
disease impacts to POW flying squirrels. In areas where the southern 
flying squirrel (G. volans) and the northern flying squirrel coexist 
(e.g., the southern Appalachians), the southern species can infect the 
northern species with a nematode (Strongyloides robustus) that can 
cause huge die-offs of northern flying squirrels (Weigl 2007, pp. 901-
902). However, we are unaware of any such occurrence in POW flying 
squirrel populations in Southeast Alaska.
    In summary, we find that the information provided in the petition, 
as well as other information in our files, does not present substantial 
scientific or commercial information indicating that disease or 
predation may be a threat to the POW flying squirrel. The POW flying 
squirrel does not avoid forest edges where predation risk is assumed to 
be greatest and is not impacted at the population level by introduced 
predators within the POW Complex. We conclude that the information 
presented in the petition does not establish a connection between 
habitat fragmentation and predation risk to the POW flying squirrel. 
The potential predators identified in the petition are not widespread 
or established and do not feed on squirrels regularly. Furthermore, POW 
flying squirrels do not avoid edges and may in fact select for them, 
suggesting that individual squirrels do not perceive increased 
predation risk at or near forest edges, as stated in the petition. We 
did not find any information describing existing or potential disease 
impacts to POW flying squirrels.

D. The Inadequacy of Existing Regulatory Mechanisms.

Information Provided in the Petition
    The petitioner identifies perceived inadequacies of the most recent 
Tongass Land Management Plan (2008) to protect old-growth forest 
habitats and reserve connectivity required to support metapopulations 
of POW flying squirrels across their range. The primary concern 
described in the petition relates to the efficacy of small old-growth 
reserves and the ability of POW flying squirrels to glide across large 
clearcuts. Flaherty et al. (2008, p. 1055) concluded that the 
perceptual range, the distance at which an animal can perceive a 
particular habitat or landscape feature (Lima and Zollner 1996 [in 
Flaherty et al. 2008, p. 1051]) of the POW flying squirrel is 109-164 
yd (100-150 m) in clearcuts and 27-55 yd (25-50 m) in second-growth 
forest. Both distances are shorter than the average width of clearcuts 
on POW Island (~394 yd [360 m]). The petitioner asserts that if 
individuals are not capable or willing to cross large openings, 
squirrel populations will become isolated and may be extirpated.
    In addition to POW flying squirrel movement and habitat 
connectivity, the petitioner raises concern about forest composition, 
patch size, and land ownership and population viability of squirrels. 
Old-growth forests are not equal in ecological value; there are 
structural differences between old-growth forests of mixed conifer, 
peatland, and Sitka spruce and western hemlock. The petitioner claims 
that the POW flying squirrel may utilize second-growth forests, but 
they depend on old-growth forests for their survival. Private lands are 
not subject to the same forest management practices as those outlined 
in the Tongass Land Management Plan, and, therefore, these private 
lands are not protected and are subject to development.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    Similar to Factor A, the petitioner assumes that the POW flying 
squirrel requires productive, old-growth forest to meet their life-
history needs, including survival, reproduction, and movement, and we 
did not find substantial information in the petition or our files to 
support this assumption. The Tongass Land Management Plan is designed 
to provide adequate amounts of forest habitat and connectivity of 
suitable structure and composition to maintain viable populations of 
the POW flying squirrel. Smith and Person (2007, pp. 631-633) concluded 
that small old-growth reserves are too small to assure a high 
probability (greater than 90 percent) of sustaining flying squirrel 
populations, but their simulations relied on the unrealistic assumption 
of no immigration and do not consider the other matrix components, such 
as medium and large reserves and stream and beach corridors (see Factor 
A for details on the composition of reserves and land status). As noted 
above in

[[Page 52307]]

Factor A, the majority (~97 percent) of land within the POW Complex is 
subject to prescriptions and guidelines outlined in the Tongass Land 
Management Plan; a very small proportion of the land is privately 
owned. We do not believe that the lack of protection of these non-
Federal lands presents a threat to the POW flying squirrel.
    We lack population trend estimates of the POW flying squirrel and, 
therefore, are unable to evaluate reliably the efficacy of forest 
management practices or critical components of the conservation 
strategy for squirrel populations in the POW Complex. However, over the 
last 50-60 years, extensive timber harvesting has occurred within the 
POW Complex, reducing the total amount of old-growth forest from 
989,778 ac (400,549 ha) to 722,010 ac (292,187 ha; 27 percent, as of 
2006; in petition, p. 20) with most of the logging occurring prior to 
the implementation of the conservation strategy in 1997. The POW flying 
squirrel not only persisted during this period of heavy timber removal 
and no conservation strategy, but also appears to be utilizing and 
dispersing successfully across the managed landscape (Bidlack and Cook 
2002, pp. 250-252; Smith et al. 2003, p. 1049; Pyare et al. 2010, pp. 
889-891).
    In light of this information, we find that the information provided 
in the petition, as well as other information in our files, does not 
suggest that the inadequacy of existing regulatory mechanisms may be a 
threat to the POW flying squirrel. The POW flying squirrel is not an 
old-growth obligate species, is moving and dispersing successfully 
across the managed landscape, and is persisting in apparently viable 
populations under the existing conservation strategy and management 
guidelines in the Tongass Land Management Plan. As in the analysis for 
Factor A, we conclude that the information provided in the petition 
describing this threat relies on unsupported assumptions and does not 
fully recognize all components of the conservation strategy under the 
Tongass Land Management Plan.

E. Other Natural or Manmade Factors Affecting Its Continued Existence

Information Provided in the Petition
    The petitioner identified climate change and the introduction of 
the American red squirrel (Tamiasciurus hudsonicus) as potential 
threats to persistence of POW flying squirrels. Specifically, increased 
temperatures and fires, heavy winds, warmer sea temperatures and sea 
level rise were proposed as environmental changes that may result from 
changing climatic conditions and may affect POW flying squirrels. The 
red squirrel was implicated as a competitor to the POW flying squirrel 
for some food resources.
Evaluation of Information Provided in the Petition and Available in 
Service Files
    Most climate models for Southeast Alaska predict warmer and wetter 
weather with increases in rainfall and decreases in snowfall, 
especially at lower elevations, over the next 50-100 years (Bonsal and 
Prowse 2006, pp. 33-40). Despite higher projected precipitation, 
forests may be drier during summer months, and, therefore, fire, which 
currently is very uncommon in Southeast Alaska, may occur more often 
(Haufler et al. 2010, p. 18). However, it is difficult to assess 
potential impacts of increased fire on POW flying squirrel populations. 
Fire is a common event across most of the range of the northern flying 
squirrel, which encompasses the boreal, coniferous, and mixed forests 
of the northern United States and Canada and the slopes of the 
mountains of the east and west, and it is quite clear that this species 
has experienced a number of range contractions in the past (Weigl 2007, 
pp. 897-898).
    In Southeast Alaska, loss of snow cover at low elevations is 
causing changes in the distribution and decreasing the survival of 
yellow cedar (Callitropsis nootkatensis; Haufler et al. 2010, pp. 19-
20). The resulting die-offs of yellow cedar stands temporarily increase 
the availability of snags for denning squirrels, but also provide fuel 
for potential fire events in the future. However, yellow cedar stands 
are not common on the POW Complex (1.3 percent; 29,425 ac [11,908 ha]), 
and, therefore, loss of these stands to fire, should it occur, would 
not result in a substantial loss of habitat for the flying squirrel. We 
did not find any information to connect sea level rise or warmer sea 
temperatures to POW flying squirrel ecology or persistence. Therefore, 
impacts to the POW flying squirrel from predicted changes in climate do 
not appear to be a population-level threat to the subspecies.
    The petitioner stated that the American red squirrel, a potential 
competitor to the POW flying squirrel, was introduced to POW Island, 
but no citation was provided in support of this claim (petition, p. 
21), nor have we found any information supporting this statement in the 
literature or our files (e.g., Paul 2009, p. 111). Furthermore, 
MacDonald and Cook (2007, p. 26) do not include POW Island or Complex 
in the current range of the red squirrel. The red squirrel was 
introduced to other large islands in Southeast Alaska, such as, 
Admiralty, Baranof, and Chichagof islands, but there is no mention of 
any islands within the range of the POW flying squirrel (Paul 2009, p. 
111).
    In summary, we find that neither the information provided in the 
petition nor any other information in our files presents substantial 
scientific or commercial information indicates that other natural or 
manmade factors may be a threat to the POW flying squirrel. Potential 
impacts from changes in climate are contradictory and difficult to 
evaluate reliably, and the information presented in the petition 
regarding changes in climate is speculative and unsubstantiated. We 
found no reliable information indicating that red squirrels have been 
introduced within the range of the POW flying squirrel, contrary to 
what is stated in the petition.

Finding

    In summary, the petition does not present substantial information 
that listing may be warranted. The POW flying squirrel is a habitat 
opportunist that occupies a diversity of forested habitats (Smith et 
al. 2003, p. 1049), eats a variety of food items (Flaherty et al. 2010, 
p. 85), moves among remnant forest patches (Pyare et al. 2010, pp. 889-
891), and disperses successfully across the landscape (Bidlack and Cook 
2002, pp. 250-252). In the absence of population trend of the POW 
flying squirrel, the petitioner relies heavily on a presumption of 
dependency of this species on old-growth habitats and its inability to 
disperse across the forest openings caused by clearcuts. We find most 
of the information to be speculative or unsubstantiated even when 
augmented with the information in our files. This is especially true 
when considering the protections afforded the POW flying squirrel under 
the conservation strategy outlined in the Tongass Land Management Plan. 
Neither the information in the petition nor the information available 
in our files suggest that the Prince of Wales flying squirrel may be in 
danger of extinction or likely to become so now or in the foreseeable 
future.
    Under section 4(b)(3)(A) of the Act, we conclude that the petition 
does not present substantial scientific or commercial information to 
indicate that listing the Prince of Wales flying squirrel under the Act 
as a threatened or endangered species may be warranted at this time. 
Although we will not review

[[Page 52308]]

the status of the species at this time, we encourage interested parties 
to continue to gather data that will assist with the conservation of 
the Prince of Wales flying squirrel. If you wish to provide information 
regarding the Prince of Wales flying squirrel, you may submit your 
information or materials to the Field Supervisor, Juneau Fish and 
Wildlife Field Office (see ADDRESSES), at any time.

References Cited

    A complete list of references cited is available on the Internet at 
https://www.regulations.gov and upon request from the Juneau Fish and 
Wildlife Field Office (see FOR FURTHER INFORMATION CONTACT).

Author

    The primary authors of this notice are the staff members of the 
Juneau Fish and Wildlife Field Office (see ADDRESSES).

Authority

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

    Dated: August 20, 2012.
Benjamin Tuggle,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2012-21232 Filed 8-28-12; 8:45 am]
BILLING CODE 4310-55-P