[Federal Register Volume 80, Number 220 (Monday, November 16, 2015)]
[Rules and Regulations]
[Pages 70700-70717]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2015-28742]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
[Docket No. FWS-R5-ES-2014-0021; FXES11130900000; 4500030113]
RIN 1018-AY83
Endangered and Threatened Wildlife and Plants; Removal of the
Delmarva Peninsula Fox Squirrel From the List of Endangered and
Threatened Wildlife
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Final rule.
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SUMMARY: The best available scientific and commercial data indicate
that the Delmarva Peninsula fox squirrel (Sciurus niger cinereus) has
recovered. Therefore, under the authority of the Endangered Species Act
of 1973, as amended (Act), we, the U.S. Fish and Wildlife Service
(Service), remove the Delmarva Peninsula fox squirrel (commonly called
the Delmarva fox squirrel) from the Federal List of Endangered and
Threatened Wildlife (List). This determination is based on a thorough
review of all available information, which indicates that the
subspecies is now sufficiently abundant and well distributed to
withstand foreseeable threats and no longer meets the definition of an
endangered or threatened species under the Act.
This rule removes the Delmarva fox squirrel from the List
throughout its range, including the experimental population designated
for Assawoman Wildlife Management Area in Delaware. It also announces
the availability of a post-delisting monitoring plan for the
subspecies.
DATES: This rule is effective December 16, 2015.
ADDRESSES: This final rule and the post-delisting monitoring plan are
available on the Internet at http://www.regulations.gov under Docket
No. FWS-R5-ES-2014-0021. Comments and materials received, as well as
supporting documentation used in rule preparation, will be available
for public inspection, by appointment, during normal business hours at:
U.S. Fish and Wildlife Service, Chesapeake Bay Field Office, 177
Admiral Cochrane Drive, Annapolis, MD 21401; and on the Chesapeake Bay
Field Office Web site at: http://www.fws.gov/chesapeakebay/.
FOR FURTHER INFORMATION CONTACT: Field Office Supervisor, Genevieve
LaRouche, by telephone at 410-573-4573; or Cherry Keller, Wildlife
Biologist, at 410-573-4532, or by email
[[Page 70701]]
at [email protected]. Written questions or requests for additional
information may also be directed to: Delmarva fox squirrel QUESTIONS,
at the street address listed under ADDRESSES. Individuals who are
hearing-impaired or speech-impaired may call the Federal Relay Service
at 1-800-877-8337 for TTY assistance.
SUPPLEMENTARY INFORMATION:
Background
Previous Federal Action
On September 23, 2014, the Service published a proposed rule (79 FR
56686) to remove the Delmarva Peninsula fox squirrel, commonly called
and hereafter referred to as the Delmarva fox squirrel (DFS), from the
List of Endangered and Threatened Wildlife (List). In the proposed
rule, we solicited information and comments from the public and
scientific experts for 60 days, ending November 24, 2014. Later in this
document, we discuss comments we received. For more information on
previous Federal actions concerning the Delmarva fox squirrel, refer to
the proposed rule available at http://www.regulations.gov under Docket
No. FWS-R5-ES-2014-0021.
Species Information
The Delmarva fox squirrel (Sciurus niger cinereus), a subspecies of
the eastern fox squirrel (Sciurus niger) found only on the Delmarva
Peninsula, is located between the Chesapeake Bay and the Atlantic Ocean
in portions of Maryland, Delaware, and Virginia. The DFS is a large,
silver-gray tree squirrel with white underparts and a wide tail. It
inhabits mature forests of mixed hardwoods and pines within the
agricultural landscapes of the Delmarva Peninsula and is not typically
found in suburban settings. The DFS is also associated with forests
that have a relatively open understory (Dueser et al. 1988, entire;
Dueser 2000, entire) or where understory shrubs are clumped, leaving
other open spaces (Morris 2006, p. 37). While these squirrels need
mature forest for both feeding and denning, they can travel and forage
in other areas, including clearcuts, young forests, and agricultural
fields.
As a member of the Order Rodentia, the DFS has a life history with
good potential for population increase. For example, females breed at 1
year of age, litter sizes range from two to four young, some females
have potential for two litters in 1 year, and lifespans can reach 6 to
7 years in the wild. Den sites are frequently found in tree cavities,
but leaf nests may also be used. Home ranges of the DFS vary
considerably but are typically 12 to 16 hectares (ha) (30 to 40 acres
(ac)), and individual home ranges overlap (Flyger and Smith 1980;
entire, Paglione 1996; entire, Pednault-Willett 2002, p. 109).
Densities range from 0.36 to 1.29 DFS per ha (0.15 to 0.5 DFS per ac),
averaging 0.82 DFS per ha (0.33 DFS per ac) (Paglione 1996, p. 28;
Pednault-Willett 2002, pp. 85-104).
Historically, this subspecies had a patchy distribution throughout
most of the Delmarva Peninsula and into southern Pennsylvania, but by
the time of its listing in 1967 (32 FR 4001; March 11, 1967), remnant
populations occurred in only four Maryland counties (Taylor 1976,
entire); this range contraction was most likely caused by land use
changes and hunting. When the subspecies was listed, its distribution
had been reduced to only 10 percent of the Delmarva Peninsula. After
listing, the hunting season for this subspecies was closed, and
recovery efforts focused on expanding the squirrel's distribution
through translocations. In addition, new populations have been
discovered since the time of listing (particularly since more intensive
search efforts were initiated), and there are now many more areas of
forest known to be occupied by the DFS.
The squirrel's current occupied range is defined as the area within
4.8 kilometers (km) (3 miles (mi)) of credible DFS sightings. As of the
2012 status review for the DFS, this covered 28 percent of the Delmarva
Peninsula, including 10 of the 14 peninsular counties (8 counties in
Maryland and 1 each in Delaware and Virginia) and 54,543 ha (134,778
ac) of occupied forest (USFWS 2012, based on 2010 data). Since that
time, new sightings have continued to occur and an updated overview of
its range as of 2013 is provided below in Table 1. An additional
population discovered in Worcester County, Maryland, is the first
population found there that was not a result of a translocation. Figure
1 shows range changes between the time of the 1993 recovery plan and
the present decade.
Table 1--Known Occupied Range of the DFS, 1970 to 2013
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Year
Occupied range -------------------------------------------------------------------------------------------------------------------------
~ 1970 1990 2005 2010 2013
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Number of counties in the 3...................... 3...................... 6..................... 6..................... 7.
range (without
translocations).
Number of counties in the 4...................... 10..................... 10.................... 10.................... 10.
range (with translocations).
Total acres of occupied forest N/A.................... 103,311................ 128,434............... 134,778............... 137,363.
rangewide.
Percent of historical range 10..................... ....................... 27.................... 28.................... 28.
occupied.
Source........................ Taylor and Flyger 1974. USFWS 1993, recovery USFWS 2007, 5-yr USFWS 2012, 5-yr USFWS 2013 data.
plan. review. review.
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BILLING CODE 4333-15-P
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[GRAPHIC] [TIFF OMITTED] TR16NO15.211
BILLING CODE 4333-15-C
Summary of Changes From the Proposed Rule
We have not made any substantive changes in this final rule based
on the comments that we received during the public comment period on
the September 23, 2014, proposed rule (79 FR 56686), but we have added
or corrected text to clarify the information that was presented. This
information and other clarifications have been incorporated into this
final rule as discussed below in Summary of Comments and
Recommendations.
Summary of Comments and Recommendations
In the proposed rule published on September 23, 2014 (79 FR 56686),
we requested that all interested parties submit written comments on the
proposal by November 24, 2014. We also solicited peer review of the
scientific basis for the proposal (see Peer Review Comments, below),
and contacted appropriate Federal and State agencies, scientific
experts and organizations, and other interested parties and invited
them to comment on the proposal. Newspaper notices inviting general
public comment were published in the Baltimore Sun, placed on Service
Web sites, and advertised by other online media outlets (e.g., http://
www.wboc.com/story/26574688/
[[Page 70703]]
maryland-state-officials-set-to-discuss-delmarva-peninsula-fox-
squirrel). We did not receive any requests for a public hearing.
During the public comment period for the proposed rule, we received
a total of 129 comment letters. Of these, 74 provided substantive
comments that we address below, including one letter from the State of
Maryland and comments from two peer reviewers. Both peer reviewers
asked for additional detail on the life history of this subspecies,
which we have provided in the supplemental documents that can be found
at http://www.regulations.gov under Docket No. FWS-R5-ES-2014-0021. All
substantive information provided during the review period either has
been incorporated directly into this final determination or into the
supplemental documents, or is addressed below.
Comments From States
(1) Comment: The State of Maryland's Department of Natural
Resources (DNR) was supportive of the proposed rule and concurred with
our findings. The DNR added that it would continue to provide
protection to the DFS under the authority of Maryland's Nongame and
Endangered Species Conservation Act, although likely not at the
endangered level. The DNR also stated that the post-delisting
monitoring plan proposed by the Service was adequate to document
expansion or contraction of the range of the DFS and that the agency
would participate in the monitoring effort.
Our Response: We are in agreement with the DNR and appreciate its
commitment to continued conservation.
Public Comments
(2) Comment: Several commenters expressed concern that the DFS
would be hunted after delisting, and that populations would then
decline and might require relisting.
Our Response: As explained in the proposed rule and supplementary
documents (see Post-delisting Monitoring Plan, appendices D through F),
after delisting, the State of Maryland intends to keep the DFS on the
State list of endangered and threatened species as a Species of
Conservation Concern; this status does not allow a hunting season. This
intention is reinforced by the State of Maryland's comment letter
reiterating that the subspecies will remain State-listed as described
above.
The State of Delaware also intends to keep this subspecies on its
State list of endangered and threatened species, and no hunting of the
DFS will be allowed after delisting. The State has written a management
plan for the DFS (DNREC 2014) that calls for adding two additional DFS
populations in the State, likely through translocations.
In the State of Virginia, all DFSs are currently on the
Chincoteague National Wildlife Refuge, where they will not be hunted.
The State has evaluated locations for potential translocations of DFSs
in the future, but any future translocated populations are not expected
to be subject to hunting. Enhancement of DFS populations in Virginia
would be primarily aimed at restoring the native fauna of Virginia.
(3) Comment: Several commenters stated that the occupancy of 28
percent of the historical range was insufficient to warrant delisting.
Our Response: The Act is legislation intended to prevent extinction
of native species and does not describe recovery in terms of the
proportion of a historical range that is occupied by a species. We do
take into account in our listing and delisting determinations the
effects that loss of historical range may have on the current and
future viability of a species. As explained in our significant portion
of the range (SPR) final policy (79 FR 37578; July 1, 2014), we have
concluded that this consideration is sufficient to account for the
effects of loss of historical range when evaluating the current status
of a species. The purposes of the Act, stated in section 2, are to
provide a means to conserve the ecosystems upon which endangered
species and threatened species depend and to provide a program for the
conservation of endangered species and threatened species. The Act
itself does not contain the phrase ``historical range,'' nor does it
ever allude to restoration throughout the entire historical range as a
conservation purpose.
Some concerns about the current range of the DFS likely stem from a
frequently quoted reason for listing, ``the species was listed because
it declined to 10 percent of its historical range'' (USFWS 1993, p. 1).
However, the substantial population decline as evidenced by that range
decline is the actual reason for the listing. In 1944, the DFS was
found in seven counties (Dozier and Hall 1944), but by 1967, it was
known to occur in only four counties; thus, the decline would have been
apparent and reasonably concerning to many biologists at the time of
listing.
(4) Comment: Several commenters stated that the total number of
animals in the rangewide population did not appear to be large enough
to warrant delisting and expressed a concern that the population would
decline again after delisting.
Our Response: As described in the proposed rule, the best estimate
of the rangewide number of the DFS at the time of the 2012 status
review was 22,368 (USFWS 2012, p. 20), which we can approximate as
20,000. However, the critical question with regard to the listing
status of the subspecies is not a specified number of individuals;
rather, it is the level of extinction risk, indicating whether the
subspecies meets the definition of endangered or threatened. To address
this question, we conducted a population viability analysis (PVA) for
the DFS (Hilderbrand et al. 2007, entire), which enabled us to evaluate
how the foreseeable threats may affect the probability of extinction of
DFS subpopulations (USFWS 2012, pp. 18-21, 23-44).
The Hilderbrand et al. (2007) PVA model indicates that a population
of 130 animals would have a 95 percent chance of persisting for 100
years. This threshold, also called a minimum viable population (MVP),
provides a useful benchmark of extinction risk. It should not be
mistaken for a recovery goal but is, rather, a population size with an
associated extinction risk based on the life history of the DFS before
assessing additional threats. This PVA includes variations in adult and
juvenile survival, the number of young produced per year, and
variability in environmental effects.
Using this model, we estimate that the known occupied forest within
the range of the DFS contains a total population that is 171 times the
MVP and that, even under the worst-case scenarios for threats,
including inundation of areas up to 0.6 meters (m) (2 feet (ft)) above
sea level due to sea level rise, we would still have a total population
that is 145 times the MVP. Further, our analysis indicates that the
rangewide population would comprise at least 15 subpopulations broadly
distributed across the Delmarva Peninsula. After considering the
conservation imperatives of habitat availability, habitat connectivity,
population resiliency and redundancy, and genetic and/or ecological
representation, we concluded that the risk of extinction is low, even
under a worst-case scenario, and that the current population is
sufficiently abundant and well distributed to withstand foreseeable
threats.
(5) Comment: Several commenters stated that sea level rise was a
great concern, and that threats from climate change and sea level rise
have not been eliminated.
Our Response: We agree that climate change and sea level rise
trends are continuing; nonetheless, the pertinent
[[Page 70704]]
question is whether these factors are likely to threaten the DFS with
extinction or with endangerment in the foreseeable future. We analyzed
the impact of sea level rise and associated habitat loss on the DFS
using a worst-case scenario of 0.6 m (2 ft) of inundation within 40
years. As stated in our response to Comment 4, we evaluated this factor
along with a number of other factors with the potential to affect the
long-term viability of DFS subpopulations (noting that various
conditions can occur on the landscape and threaten some species and not
others depending on the abundance, distribution, and life history of
the species). After considering habitat availability and connectivity,
as well as population resiliency, redundancy, and representation, we
conclude that the risk of extinction is low even under the worst-case
sea level rise scenario (see Summary of Factors Affecting the Species,
Factor A), given projected population levels and distribution, and the
ability of the DFS to colonize unoccupied habitat as described in the
September 23, 2014, proposed rule (79 FR 56686) and 2012 status review
(USFWS 2012).
(6) Comment: One commenter expressed two concerns regarding DFS
movements in response to sea-level rise: First, during sea level rise,
individual animals would not be able to move inland because DFSs prefer
moving on the ground and would be unable to move across habitat that
became flooded. Second, with the occurrence of sea-level rise and the
associated loss of habitat, populations would not be able to shift
inland over time.
Our Response: DFSs have always been abundant in southern Dorchester
County, where forests are frequently flooded in the spring and are
often exposed to high tidal surges. Further, DFSs have been observed
moving across marshlands to other woodlands (L. Miranda 2010 and C.
Keller pers. comm. 2009) and moving through flooded woodlands on logs
and hummocks as well as through the trees (C. Bocetti pers. comm.
2015). In these same areas, marked animals have been documented to move
4 km (2.5 mi) and return within a season, despite intervening streams
and associated marshlands 100 m (328 ft) wide or greater (C. Bocetti
pers. comm. 2015). Typical home ranges are about 16.2 ha (40 ac) in
size and generally include forested wetlands, indicating that DFSs
already inhabit forests that experience periodic flooding.
Sea level rise is likely to result in more frequent flooding and
storm and tidal surges, with gradual deterioration of habitat at the
shoreline edges. It is therefore likely that individual animals will
need to shift their home range inland and that the overall population
will shift inland as well. The ability of DFSs to shift their home
ranges in response to habitat change has already been demonstrated as
individual animals moved to new areas following clearcuts in portions
of their home ranges (Paglione 1996); we note that clearcutting is a
more rapid and dramatic habitat alteration than would be expected from
flooding or storm surges.
In terms of available habitat for the DFS to move into following
storm events and/or sea level rise, we evaluated the rangewide
availability and connectivity of forest patches in the 2012 status
review (USFWS 2012) by mapping the connectivity of forest patches
relative to dispersal of DFS subpopulations (USFWS 2012, figures 9 and
10). After quantitative analysis of habitat that could be lost due to
sea level rise and development (USFWS 2012, table 7), we concluded that
even if all potentially affected habitat was lost immediately,
remaining DFS populations would still be sufficiently abundant and well
distributed to alleviate the risk of extinction.
With regard to the connectivity needed to allow DFSs to move to
more upland habitats, we recognize that sea-level rise can widen rivers
and increase obstacles to DFS movement, especially from west to east in
southern Dorchester County. However, even with maximum projected
inundation, DFSs could disperse from southern Dorchester without
crossing streams. In addition, southern Dorchester County would still
contain about 2,400 to 3,200 ha (6,000 to 8,000 ac) of suitable
occupied habitat, supporting at least six times the MVP. Given this, we
predict long-term population viability in these areas of Dorchester
County.
(7) Comment: One commenter stated that the DFS should not be
delisted because it has not met all of the recovery criteria contained
in the most recent DFS recovery plan (USFWS 1993). In particular, the
commenter contended that our analysis of recovery criterion 6 does not
adequately support our conclusion that this criterion has been met.
Our Response: We will respond first to the issue of whether
recovery criteria must be met in order to delist a species, and second
to the issue of whether criterion 6 has been met.
Notwithstanding our conclusion that the recovery criteria for the
DFS, as required under section 4(f) of the Act, have been met, this is
not the requisite analysis for determining the appropriate listing
status of the species. Rather, listing determinations must be made in
accordance with sections 4(a)(1) and 4(b) of the Act. Section 4(a)(1)
requires that the Secretary determine whether a species is endangered
or threatened because of one or more of five threat factors, while
section 4(b) requires that the determination be made ``solely on the
basis of the best scientific and commercial data available.'' Thus, any
determination to delist a species must be based on the best information
available at the time of the determination and the results of the five-
factor analysis, notwithstanding any information in the recovery plan.
Although meeting recovery criteria is not essential for determining
a species' listing status, our most recent status review (USFWS 2012)
led us to the conclusion that all recovery criteria for the DFS,
including criterion 6, have been met. Criterion 6 states that
``mechanisms that ensure perpetuation of suitable habitat at a level
sufficient to allow for desired distribution [must be] in place and
implemented within all counties in which the species occurs.'' Our
analysis showed that there are many State and Federal laws and land
protection programs in place that actively protect land at the present
time and will continue to do so into the future. A detailed table and
map of the land protected by these programs in each county is provided
for each county in the 2012 status review (USFWS 2012, table 5 and
figure 7). These protective mechanisms are also presented in our
analysis of Factor D (USFWS 2012, pp. 38-39), with a detailed
description of each program provided in appendix D of the same
document. These data clearly portray the adequacy of these regulatory
mechanisms.
(8) Comment: One commenter stated we had not adequately addressed
the future of the translocated population of the DFS at Chincoteague
National Wildlife Refuge (NWR) due to the projections in sea level
rise.
Our Response: We agree with the commenter that this coastal
population of the DFS, inhabiting Assateague Island, a barrier island,
is vulnerable to reduced habitat and isolation from sea level rise, and
we discussed this situation in the September 23, 2014, proposed rule
(79 FR 56686). We also discuss it below, under Factor A: Loss of forest
habitat from sea level rise, where we note that although the island's
beaches, marshes, and shorelines are vulnerable to sea level rise, most
of the forest habitat occupied by the DFS is above the 0.6 m (2 ft)
inundation worst-case scenario. Even so, Refuge managers
[[Page 70705]]
are aware of the risks of sea level rise and are actively exploring
management responses to this factor. As stated in the proposed rule:
``Sea level rise is expected to cause severe losses to beach and tidal
flat habitat but currently upland habitat would only be reduced by 4 to
8 percent (National Wildlife Federation 2008, p. 69). [Chincoteague's]
Comprehensive Conservation Plan [CCP] commits to continued forest
management to maintain suitable habitat for Delmarva fox squirrels and
continued monitoring of Delmarva fox squirrel populations.'' The draft
CCP is available at: http://www.fws.gov/nwrs/threecolumn.aspx?id=2147550165.
We consider it highly likely that a DFS population will persist on
Chincoteague NWR for the foreseeable future, although there may be a
shift in the habitats that are occupied. Nonetheless, even if the
Chincoteague population were to be lost, this would not cause a
rangewide risk of extinction (USFWS 2012, table 7).
(9) Comment: One commenter stated, ``In its 2007 and 2012 status
reviews, the Service concluded that these recovery criteria were not
based on the best available science and did not represent the most up-
to-date information on the biology of the DFS. And the Service also
concluded in these status reviews that the recovery criteria did not
specifically address all of the five threat-based listing factors.''
Our Response: The commenter may be referring to sections 2.2.2.1
and 2.2.2.2 of the referenced status reviews (USFWS 2007, p. 3; USFWS
2012, p. 5):
``2.2.2.1 Do the recovery criteria reflect the best available and
most up-to-date information on the biology of the species and its
habitat? No. More recent information on the squirrel's distribution,
subpopulation delineation, and population persistence is not reflected
in the 1993 recovery criteria. Nonetheless, these criteria continue to
act as generally appropriate measures of recovery.
2.2.2.2 Are all of the relevant listing factors addressed in the
recovery criteria? No. None of the recovery criteria specifically
addresses any of the five listing factors, although habitat-related
threats are alluded to. The criteria evaluate the biological status of
the species.''
These statements are intended to convey that although new
information had become available since 1993, the recovery criteria were
still considered adequate for assessing DFS recovery progress. With
regard to criteria addressing the five listing factors, the lack of
specific threats-based criteria is typical of recovery plans at that
time and does not preclude a separate five-factor analysis (see Comment
7, above). Significantly, since the two status reviews analyze both the
recovery criteria and the five listing factors, each review constitutes
a complete assessment of the status of the species (USFWS 2007; USFWS
2012). Overall, the two status reviews and the September 23, 2014,
proposed rule (79 FR 56686) are based on the best available information
on the biology of the DFS and the threats to its long-term viability.
(10) Comment: One commenter noted that the population data in the
2012 status review were the same as those in the 2007 review and
suggested that this showed there was no increase in the population or
range between those two time periods. The commenter further suggested
that there was a decrease in DFS-occupied forest between 2007 and 2012.
The commenter stated that despite the information for the two status
reviews being essentially the same, different conclusions were reached.
Our Response: It is not clear how the commenter's interpretation of
the data in the two reviews was made. Both the September 23, 2014,
proposed rule (79 FR 56686 Table 1) and the 2012 status review (Chart
2) clearly show an increase in the area of occupied forest from 51,975
ha (128,434 ac) in 2005, to 54,543 ha (134,778 ac) by 2010; a map
illustrating the changes in the range between the two reviews is also
provided (USFWS 2012, figure 3). Since 2010, we have continued to
document new areas of occupied forest and provide an updated number of
55,589 ha (137,363 ac) as of 2013 (79 FR 56686, September 23, 2014,
Table 1).
The rangewide population estimates in the 2007 and 2012 reviews
differ only slightly (19,265 versus 22,368 animals, respectively), but
as described in the 2012 review, the two estimates were based on
different survey methods. Light detection and ranging (LiDAR) data,
which allow us to distinguish between mature forests and other forested
areas, were not available for the 2007 status review. We were able to
use a more refined and conservative approach in the 2012 review and
estimated the rangewide population using only occupied mature forest.
Both estimates are intended to provide a general measure of the
rangewide population size (USFWS 2007, p. 8; USFWS 2012 p. 20).
It should also be noted that in the 2007 review, we concluded that
DFS recovery was imminent. We indicated that a final listing
recommendation was pending while we obtained and analyzed LiDAR data,
and that, if new information continued to support our finding that DFS
habitat availability and connectivity were likely to persist over the
foreseeable future, we would recommend initiation of delisting when the
LiDAR analysis was completed (USFWS 2007, p. 27).
(11) Comment: One commenter was concerned because 9 of 22
subpopulations (40 percent) appear to be vulnerable to extirpation.
Our Response: This concern does not take into account the relative
size of these subpopulations. As described in the 2012 status review
(USFWS 2012, p. 42, figure 5 and table 7), there is a higher
vulnerability to extirpation for 9 smaller subpopulations, but the vast
majority (95 percent) of DFSs occurs in 11 large, secure
subpopulations. This provides a solid indication of continued
persistence and growth of the rangewide population. Most of the smaller
populations originated as translocations, which have become well
established and have contributed to the expanded distribution of the
subspecies. Further, as shown by the 2007 population viability analysis
(Hilderbrand et. al 2007), if one or more small populations blink out,
the rangewide population is still not vulnerable to extinction; even
accounting for all projected losses from sea level rise and
development, the rangewide population will still be 145 times the MVP,
indicating long-term viability.
Peer Review Comments
In accordance with our peer review policy published on July 1, 1994
(59 FR 34270), we solicited expert opinion from five independent
scientists with expertise that included familiarity with the DFS and
its habitat, biological needs, and threats. We received responses from
two of the peer reviewers.
We reviewed comments received from the peer reviewers for
substantive issues and new information regarding the status of the DFS.
The peer reviewers generally concurred with our methods and conclusions
and considered the scientific information to be correct and the
analyses to be sound. However, both reviewers identified parts of the
document that could be strengthened. Peer reviewer comments are
addressed below and incorporated as appropriate into the final rule or
supplemental documents, available at http://www.regulations.gov under
Docket No. FWS-R5-ES-2014-0021.
(12) Peer Review Comment: Both reviewers asked for more detail to
be provided on life history of the subspecies.
[[Page 70706]]
Our Response: We have added more life-history information in a
supplemental document for the final rule, particularly life history
related to reproduction, litter size, and survival. The supplemental
document is available at http://www.regulations.gov under Docket No.
FWS-R5-ES-2014-0021.
(13) Peer Review Comment: One reviewer asked for clarification on
the length of time that agreements preventing development on private
lands would continue.
Our Response: The private lands we consider protected from
development have easements that extend in perpetuity, and this has been
added to the text of this rule.
(14) Peer Review Comment: Both reviewers thought that the rate of
future development might be underestimated and suggested possibly using
zoning or projected road development as additional sources of
information.
Our Response: We consider the analysis of future development
conducted by the Maryland Department of Planning to be the best
available source of information on development trends insofar as this
office has both the responsibility for tracking such information and
the requisite expertise to make trend projections. The September 23,
2014, proposed rule (79 FR 56686) and 2012 status review (USFWS 2012)
used data from Maryland's 2008 planning report (Maryland Department of
Planning 2008a), as this was the most current information at the time;
the same trends and areas of expected development are also mapped in a
more recent planning document (Maryland Department of Planning 2011a).
The data continue to show that the eastern shore of Maryland is far
more rural, with less development and more protected lands, than
elsewhere in Maryland. Thus, the most recent information continues to
support the past and future trends used in our previous analysis.
Consideration of zoning was not included in our analysis
specifically because zoning restrictions can be changed, making
projections based on this source of information less certain. Further,
we took a cautious approach in considering future development by
projecting complete loss of any DFS-occupied habitat within a ``Smart
Growth'' area that was not otherwise protected. (``Smart Growth'' is a
theory of land development that concentrates new development and
redevelopment in areas that have existing or planned infrastructure to
avoid sprawl.) Currently, DFSs inhabit blocks of forest within the
Smart Growth areas of both Cambridge and Easton in Maryland. Although
limited monitoring shows that DFSs have been persisting in these
woodlands over many years and may be able to continue doing so in the
future, our analysis assumes loss based on lack of ensured habitat
protection.
(15) Peer Review Comment: One peer review comment referred to the
possibility of residential development causing problems because of the
presence of free-ranging dogs that may pursue the DFS.
Our Response: We agree that this can be a problem in some
situations, and although all counties within the current range of the
DFS have regulations that require dogs to be on a leash, at heel, or
directly beside the owner, enforcing these regulations can be
difficult. Further, as noted in the status review (USFWS 2012, p. 27),
the presence of dogs may be one reason DFSs do not inhabit residential
developments. Despite these concerns, we do not consider free-roaming
dogs to be a threat that would result in population-level effects,
either individually or in combination with other possible risks, to
this subspecies, as effects are highly localized and regulations do
exist to enable management of this issue.
(16) Peer Review Comment: Both peer reviewers raised a concern
regarding the commitment to monitoring of the DFS after delisting and
questioned whether there would be long-term funds, time, and available
personnel to carry out the monitoring work described in the post-
delisting monitoring plan.
Our Response: We agree that sustaining monitoring efforts can be
challenging and subject to competing priorities. Nonetheless, we have
designed the post-delisting monitoring strategy to fit into current
work plans and are seeking additional ways in which this effort can be
incorporated into other monitoring work conducted by the States. For
example, the hunt clubs leasing the Maryland State Chesapeake Forest
lands are now asked to report sightings or camera shots which have
already provided DFS records, and we are working with the States on
other opportunities to invite hunters to report DFS sightings. We also
anticipate that DFS-occupied sites managed by conservation groups will
be monitored as part of their management efforts; sightings of DFSs are
often reported by those who live or work on these properties. Overall,
recording these sightings will enhance our ability to conduct
widespread monitoring of the DFS.
Recovery
Section 4(f) of the Act directs us to develop and implement
recovery plans for the conservation and survival of endangered and
threatened species unless we determine that such a plan will not
promote the conservation of the species. Recovery plans are not
regulatory documents and are instead intended to establish goals for
long-term conservation of a listed species; define criteria that are
designed to indicate when the threats facing a species have been
removed or reduced to such an extent that the species may no longer
need the protections of the Act; and provide guidance to our Federal,
State, and other governmental and nongovernmental partners on methods
to minimize threats to listed species. There are many paths to
accomplishing recovery of a species, and recovery may be achieved
without all criteria being fully met. For example, one or more criteria
may have been exceeded while other criteria may not have been
accomplished, yet the Service may judge that, overall, the threats have
been minimized sufficiently, and that the species is robust enough to
reclassify or delist the species. In other cases, recovery
opportunities may have been recognized that were not known at the time
the recovery plan was finalized. These opportunities may be used
instead of methods identified in the recovery plan.
Likewise, information on the species that was not known at the time
of the recovery plan may become available. The new information may
change the extent that criteria need to be met for recognizing recovery
of the species. Recovery of species is a dynamic process requiring
adaptive management that may, or may not, fully follow the guidance
provided in a recovery plan.
Despite the guidance provided by recovery plans, determinations to
remove species from the List must be made in accordance with sections
4(a)(1) and 4(b) of the Act. Section 4(a)(1) requires that the
Secretary determine if a species is endangered or threatened because of
one or more of five threat factors. Section 4(b) of the Act requires
that the determination be made ``solely on the basis of the best
scientific and commercial data available.''
Although recovery criteria, as mentioned above, help guide recovery
efforts and should always be consulted when considering a change in the
status of a listed species, the ultimate determination of whether to
reclassify or delist a species must be made in accordance with
statutory standards, and recovery criteria can neither substitute for
nor pre-empt section 4(a)(1) requirements. Ultimately, a decision to
remove a species from the
[[Page 70707]]
List is made when the best available data show that the species is no
longer an endangered species or a threatened species, regardless of how
closely this information conforms to the information and criteria in
the recovery plan.
The most recent DFS recovery plan was approved by the Service on
June 8, 1993 (USFWS 1993, entire), and updated on October 31, 2003
(USFWS 2003, entire). The plan states that ``the long-range objective
of the DFS recovery program is to restore this endangered species to a
secure status within its former range.'' The plan provides three
criteria for reclassifying the DFS from endangered to threatened
status. It then provides four additional criteria to be considered in
conjunction with the first three for delisting the DFS.
Recovery Criteria
A discussion of the extent to which each recovery criterion has
been met is provided in the proposed rule (79 FR 56686; September 23,
2014). This discussion is summarized below.
Criterion 1: Ecological requirements and distribution within the
remaining natural range are understood sufficiently to permit effective
management. A considerable body of new information has been amassed
regarding the DFS' distribution and ecological requirements, and we
thus conclude that this recovery criterion has been met. The six key
contributions to our understanding of the DFS are summarized below.
(1) DFS range and distribution: The geographic information system
(GIS) maintained for the DFS documents a significant increase in the
area occupied by the DFS since the 1993 recovery plan was issued (see
Figure 1, above). Records of DFS sightings by knowledgeable observers
and, in particular, the use of trap and camera surveys have greatly
improved our ability to determine which forest tracts are occupied by
the DFS and monitor continued presence.
(2) Population persistence: Persistence of DFS populations over the
recovery period has been evaluated through comparison of occupancy over
time, including a survey conducted in 1971 and repeated in 2001, and a
second analysis comparing occupancy from 1990 through 2010 (Table 2).
These studies are summarized in the proposed rule (79 FR 56686;
September 23, 2014) and status review (USFWS 2012, pp. 15-17).
Table 2--DFS Occupancy of 275 Forested Tracts (41,733 ha or 103,125 ac) in Maryland, 1990 Compared to 2010
----------------------------------------------------------------------------------------------------------------
Percent of the
original 41,733
Occupancy change from 1990 to 2010 Area of forest Number of forest ha (103,125 ac)
tracts in each occupancy
status
----------------------------------------------------------------------------------------------------------------
Persistence................................ 38,130 ha (94,221 ac)........ 181 91
Extirpations............................... 499 ha (1,233 ac)............ 7 1
Uncertain.................................. 3,104 ha (7,671 ac).......... 87 8
Discoveries or colonizations............... 13,042 ha (32,227 ac)........ 250 .................
----------------------------------------------------------------------------------------------------------------
As indicated in Table 2, DFSs continued to persist in the vast
majority of woodlots where they were known to occur in 1990, and their
presence was newly documented in an additional 13,042 ha (32,227 ac) in
all three States through 2010 (USFWS 2012, p. 8). Although some of
these discoveries are likely to be occurrences that were previously
present but undetected, anecdotal information indicates that several
new localities represent true range expansion (see, for example, USFWS
2012, figure 4). Using the 2010 figures for occupied forest in all
three States, as well as maps of mature forest and density estimates of
the DFS available from various studies, we estimate that the total
population of the DFS is now about 20,000 animals across an expanded
range (USFWS 2012, p. 21).
(3) Population viability: A DFS population viability analysis (PVA)
developed by Hilderbrand et al. (2007, entire) modeled the extinction
probabilities of different-sized populations and determined that a
population with 65 females, or 130 animals total, had a 95 percent
chance of persisting for 100 years. This value, also called a minimum
viable population (MVP), was used to gauge extinction risk by
projecting how many populations of this size are likely to remain
present in a given portion of the current DFS range (USFWS 2012, pp.
18-20; also see Public Comments, above).
The PVA also estimated that 75 percent of a given DFS population
would have the ability to disperse to areas within 4 km (2.5 mi)
(Hilderbrand et al. 2007, p. 73), and thus animals in forested tracts
within this distance would be likely to interbreed; these interbreeding
groups are defined as subpopulations. The analysis indicated that
approximately 85 percent of DFSs are found in four large, narrowly
separated subpopulations that could expand to become even more
connected. Each of these subpopulations contains populations estimated
to be several times the MVP minimum and have a high likelihood of
population persistence. Overall, the rangewide population, estimated at
between 17,000 and 20,000 animals, contains more than 100 times the
MVP.
(4) Effects of timber harvest: Two major studies of the effects of
timber harvest on the DFS (Paglione 1996, entire; Bocetti and Pattee
2003, entire) suggest that the subspecies is fairly tolerant of timber
harvest, although specific impacts depend on the size, location, and
landscape context of the harvest. Small clearcuts within a surrounding
forest showed relatively little impact on the DFS, with individual
squirrels shifting their home ranges into adjacent habitat, whereas
harvest of more isolated forest peninsulas forced DFSs to move greater
distances (Paglione 1996). Findings from the long-term Bocetti and
Pattee (2003) study lead to the general conclusion that the DFS can
tolerate timber harvests and can continue to occupy forested mosaics of
mature and regenerating stands. In addition, both studies suggest that
the DFS has high site fidelity and tends to shift home ranges rather
than abandon a site in response to disturbance.
(5) Habitat availability: An analysis of LiDAR data provided by the
State of Maryland enabled an inventory of mature forest suitable for
the DFS throughout most of the squirrel's range (USFWS 2012, Appendix
E). As of 2004, LiDAR mapping had identified 175,656
[[Page 70708]]
ha (434,056 ac) of mature forest in the eight Maryland counties
occupied by DFSs (55 percent of all forest was considered mature), with
17 percent currently occupied and thus over 80 percent of mature forest
available for expansion (USFWS 2012, table 4).
Although the amount and location of mature forest will change over
time with timber harvest and forest growth, these data provide good
baseline information about the availability and distribution of
suitable habitat. Mature forest is often found in riparian zones (USFWS
2012, figure 8) that can provide connected habitat for DFS dispersal
and colonization of new areas. LiDAR mapping also showed large tracts
of mature forest distributed in upland areas throughout the Maryland
portion of the subspecies' range. Given that most DFS populations occur
in Maryland and, further, that unoccupied but suitable habitat is found
both along the coast and inland elsewhere on the Delmarva Peninsula, we
can infer from this habitat inventory that there is ample unoccupied
mature forest to enable further expansion of the DFS' rangewide
population.
(6) Habitat connectivity: Lookingbill et al. (2010, entire)
conducted a GIS analysis of the connectivity between 400-ha (175-ac)
forest patches on the Delmarva Peninsula (although the DFS is not a
forest interior obligate and does not require forest blocks this
large). Study results show high connectivity of forest blocks in the
southern Maryland portion of the squirrel's range, indicating few
obstacles to DFS dispersal throughout this area. Two major forest
corridors were identified for DFS dispersal out of Dorchester County,
Maryland, one of which is already occupied by the DFS (a third
dispersal corridor not identified by the model is also DFS-occupied).
Observations of DFS movement through a wide range of habitats, in
conjunction with the results of this connectivity model and the map of
LiDAR-defined mature forests, indicate that there is sufficient habitat
availability and connectivity for further DFS range expansion.
Criterion 2: Benchmark populations are shown to be stable or
expanding based on at least 5 years of data. Criterion 2 was intended
to measure overall DFS population trends using monitoring data from
seven benchmark populations. Although a slightly different set of eight
benchmark sites was ultimately monitored, analysis of the resulting
data (Dueser 1999, entire) showed that the benchmark sites were stable
over a 5- to 7-year period, and benchmark monitoring was concluded.
We also have collected data to better understand rangewide
population trends. The distribution data that document an expanded
range and population persistence within that range as described under
criterion 1, above, are much better indicators of DFS recovery.
Although DFS populations in isolated areas (such as on small islands)
are vulnerable to extirpation, all available population data for the
DFS indicate that the range has expanded and populations are persisting
within the range, and that this recovery criterion has been met.
Criterion 3: Ten translocated colonies are successfully established
throughout the historical range. This criterion requires that at least
10 new DFS colonies must show evidence of presence for at least 5 to 8
years after release, demonstrating the ability of the DFS to colonize
new sites, whether naturally or through management.
Post-release trapping results (Therres and Willey 2002, entire),
along with more recent trapping and camera surveys, indicate continued
presence of 11 of 16 translocated colonies (69 percent) for more than
20 years (USFWS 2012, table 1, p. 83). Further, in several of these
areas, DFSs have dispersed well beyond the initial release site.
This success rate is higher than is typically found for similar
translocation efforts for other endangered species (see Fischer and
Lindenmayer 2000, p. 5), although the success rate is generally higher
for mammals and wild source populations (Wolf et al. 1996, p. 1146).
Further, despite some initial concerns about the genetic diversity of
the translocated populations, subsequent analysis indicated that their
genetic diversity was comparable to that of their source populations
(Lance et al. 2003, entire). These data indicate that this criterion
has been met.
Criterion 4: Five additional (post-1990) colonies are established
outside of the remaining natural range. Criterion 4 requires discovery
or establishment of colonies outside the range known at the time of the
1993 recovery plan, thus addressing the threat of range contraction and
providing for additional population redundancy as one component of
long-term species viability.
By 2007, eight new populations had been identified that did not
result from translocations (USFWS 2007, figure 2), expanding the range
toward the east. Notably, a colony discovered in Sussex County,
Delaware, represents the first population found in that State since the
time of listing that was not a result of a translocation. Since 2007,
additional occupied forest has been discovered between some of these
new populations, thus improving their long-term likelihood of survival
(USFWS 2012, figure 3). We therefore conclude that this recovery
criterion has been met.
Criterion 5: Periodic monitoring shows that translocated
populations have persisted over the recovery period. Criterion 5
requires the continued presence of at least 80 percent of translocated
populations, with at least 75 percent of these populations shown to be
stable or improving. All successfully established translocated
populations have persisted over the full period of recovery and have
either become more abundant on their release sites or have expanded or
shifted into new areas, as shown by trapping efforts (Therres and
Willey 2002, entire), and, more recently, both trapping and/or camera
surveys (USFWS 2012, table 1). Overall, the continued presence and
growth of DFS populations at translocation sites show that this
recovery criterion has been met.
Criterion 6: Mechanisms that ensure perpetuation of suitable
habitat at a level sufficient to allow for desired distribution are in
place and implemented within all counties in which the species occurs.
Several well-established programs protect DFS habitat from development
in perpetuity (Rural Legacy, Maryland Environmental Trust, Maryland
Agricultural Programs, etc.). These programs, along with State and
Federal ownership, protect an estimated 15,994 ha (39,524 ac; 29
percent) of DFS-occupied forest throughout the subspecies' current
range (USFWS 2012, table 3). In addition, several State laws and
regulatory programs will continue to protect forest habitat (USFWS
2012, appendix D). In Delaware and Virginia, the DFS occurs primarily
on Federal and State land; the sole Virginia population was established
on Chincoteague NWR and is completely protected from residential
development or commercial timber harvest. Overall, we conclude that
this recovery criterion has been met.
Criterion 7: Mechanisms are in place and implemented to ensure
protection of new populations, to allow for expansion, and to provide
inter-population corridors to permit gene flow among populations. As
discussed under recovery criterion 1, LiDAR data indicate that mature
forest blocks connected by riparian corridors are scattered throughout
the Delmarva Peninsula. Further, Lookingbill et al. (2010, entire)
indicate that these connected blocks constitute a good network of
forest to allow for dispersing DFSs. Given ample opportunities for
[[Page 70709]]
dispersal, and the fact that many of these corridors are protected by
State regulatory mechanisms (as discussed under The Inadequacy of
Existing Regulatory Mechanisms, below), we conclude this recovery
criterion has been met.
Summary of Factors Affecting the Species
Overview
Section 4 of the Act and its implementing regulations (50 CFR part
424) set forth the procedures for listing species, reclassifying
species, or removing species from listed status. ``Species'' is defined
in section 3 of the Act as any species or subspecies of fish or
wildlife or plants, and any distinct vertebrate population segment of
fish or wildlife that interbreeds when mature (16 U.S.C. 1532(16)). A
species may be determined to be an endangered or threatened species
based on one or more 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.
We must consider these same factors in delisting a species, and we
must show that the best available scientific and commercial data
indicate that the species is neither endangered nor threatened because:
(1) It is extinct; (2) it has recovered and is no longer endangered or
threatened (as is the case with the DFS); and/or (3) the original
scientific data used at the time of listing classification were in
error (50 CFR 424.11(d)). Determining whether a species is recovered
requires evaluation of both the threats currently facing the species
and the threats that are reasonably likely to affect the species in the
foreseeable future following delisting and removal or reduction of the
Act's protections.
A species is endangered for purposes of the Act if it is in danger
of extinction throughout all or a significant portion of its range
(SPR) and is threatened if it is likely to become endangered within the
foreseeable future throughout all or a significant portion of its
range. The word ``range'' in these definitions refers to the range in
which the species currently exists. Although the term ``foreseeable
future'' is left undefined, for the purposes of this rule, we regard
foreseeable future as the extent to which, given available data, we can
reasonably anticipate events or effects, or extrapolate threat trends,
such that reliable predictions can be made concerning the future status
of the DFS. In conducting this analysis, our general approach was to
review past threat trends and the DFS' response, followed by a
prediction of future trends. With some exceptions, we used a time frame
of approximately 40 years for both past and future trend analyses; this
time period also allowed use of available data to make more reliable
projections despite the inherent uncertainties attached to predicting
the future.
In the following five-factor analysis, we evaluate the status of
the DFS throughout its entire range. We then address the question of
whether the DFS is endangered or threatened in any significant portion
of its range. Note that information discussed in detail in the
September 23, 2014, proposed rule (79 FR 56686) and/or the 2012 status
review (USFWS 2012, pp. 26-44) is summarized for each factor below.
Factor A. The Present or Threatened Destruction, Modification, or
Curtailment of Its Habitat or Range
Here we considered habitat changes caused by residential
development, sea level rise, and commercial timber harvest, as well as
the habitat-related effects on DFS population and rangewide viability,
with the exception of development or timber harvest effects on the
population on Chincoteague NWR, as it is completely protected from
these activities; we did, however, address the impact of sea level rise
on this population.
Habitat Loss Due to Development
The Delmarva Peninsula is basically a rural landscape, but the
human population has increased since the DFS was listed, as shown by
Maryland Department of Planning data discussed in the September 23,
2014, proposed rule (79 FR 56686) (see Maryland Department of Planning
2008a, 2008b, and 2011b). Despite the past--and continuing--growth, the
majority of the Delmarva Peninsula's land base remains rural, with
approximately 47 percent agricultural land, 36 percent forest, 9
percent wetlands, and only 7 percent developed land (USFWS 2012, table
2).
Further, since listing, a variety of State laws and programs have
been put in place to counteract the rate of development across the
State (USFWS 2012, appendix D), including the Maryland Forest
Conservation Act and Maryland Critical Area Law. In addition, the
Maryland Environmental Trust, Maryland Agricultural Land Protection
Fund, and Maryland Rural Legacy Program used easements to permanently
protect about 3,642 ha per year (9,000 ac per year) of private lands
between 2000 and 2008, enhancing protection of DFS habitat (USFWS 2012,
chart 4).
Overall, approximately 30 percent of DFS-occupied forest lands,
widely distributed across the subspecies' range, is protected from
development (USFWS 2012, table 5). Additional acres of protected forest
outside the current range of the DFS provide areas for further
expansion (USFWS 2012, figure 7). Overall, the 15,995 ha (39,524 ac) of
occupied forest protected from development could support a DFS
population 45 times the MVP (based on Hilderbrand et al. 2007, entire).
However, because 70 percent of DFS-occupied forest occurs on private
land that remains legally unprotected from development, future losses
from development are likely.
We assessed the potential threat of DFS habitat loss stemming from
future development by overlaying the acres of existing occupied forest
with areas projected to be lost to development, including: (1) Smart
Growth areas (excluding the acres that are protected by easement), (2)
areas where development projects are already planned, and (3) areas
that are projected to be lost by 2030 if Smart Growth policies are not
implemented (USFWS 2012, figure 11). Overall, 3 percent (2,283 ha or
5,643 ac) of the forest area currently occupied by the DFS is
anticipated to be lost to development by 2030. This relatively low rate
of projected loss can be attributed to the likelihood that most future
development on the Delmarva Peninsula will occur outside the current
range of the DFS. Future development within the current range is
expected to primarily affect two small, isolated DFS subpopulations
where extirpation is already probable. Together these subpopulations
constitute less than 0.5 percent of the total viable population; thus,
their loss would have a negligible effect on the rangewide extinction
risk for the DFS. Although information on development projections past
2030 is not available at this time, we consider it likely that
development on the Delmarva Peninsula will continue to be concentrated
near large towns outside the range of the DFS, with some scattered
development within the subspecies' range.
Conversely, we also anticipate continued expansion of DFS
populations, including expansion onto Chesapeake Forest lands (which
are now owned and managed by the State of Maryland), noting that some
occupancy on these lands has already
[[Page 70710]]
occurred. The anticipated discovery of additional occupied forest areas
may further offset projected loss of occupied forest due to
development, resulting in little change to the overall area of the
distribution. Discovery of additional occupied forest has occurred at
the rate of 763 ha per year (1,887 ac per year) over the past 10 years.
Even if we discover new occupied forest at half that rate, the
anticipated net loss of occupied habitat from development would be
offset by known occupied habitat in 6 years. With the continued
protection of forest lands provided by State laws and programs, we do
not expect habitat loss from development to substantially elevate the
risk of the DFS' extinction.
Loss of Forest Habitat From Sea Level Rise
The Delmarva Peninsula is a low-lying landform, and sea level rise
in the Chesapeake Bay can flood and kill shoreline forests that provide
habitat for the DFS. However, the DFS does not occur exclusively in
coastal habitats, which moderates its vulnerability to this threat, and
GIS analysis indicates that over 80 percent of the current range would
remain even after a projected inundation of coastal areas by 0.61 m (2
ft); see the discussion below.
Regarding sea level rise in the past, the forces of land subsidence
and sea level rise have resulted in a long history of island loss and
formation in the Chesapeake Bay. In the last century, these forces
combined to produce a relative sea level rise in the Chesapeake Bay
region of approximately 0.3 m (1 ft) per 100 years (National Wildlife
Federation 2008, p. 2).
Loss of some forest areas in southern Dorchester County, Maryland,
is already apparent at the lowest elevations where trees have been
killed by saltwater intrusion from recent hurricanes. Although we
cannot precisely estimate how much occupied habitat has been lost in
the past 40 years, LiDAR analysis of forest height and canopy cover has
identified at least 68 ha (170 ac) at the edge of coastal marshes that
are now standing dead trees.
Hurricanes contribute to forest loss as sea levels rise, with
saltwater moving farther into forested areas during associated storm
surges. However, hurricanes and intense storms have always been part of
the weather in this region, and there is no evidence that they pose a
problem per se for the DFS. For instance, in October 2012, cameras
placed in woods to monitor DFSs near the Atlantic coast recorded DFSs
onsite after superstorm Sandy passed through, indicating survival
through the storm. Although direct loss of trees used by the DFS may
have occurred in the past, the major effect of hurricanes has been the
additional push of saltwater into more upland areas, killing coastal
forest trees.
In terms of future effects of sea level rise and climate change,
sea level rise in the Chesapeake Bay is certain to continue, and the
rate of change is likely to be even higher than in the past (National
Wildlife Federation 2008, pp. 16-17; Sallenger et al. 2012, entire;
Boesch et al. 2013, entire). To determine the extent of DFS-occupied
forest that may be lost through the combined effects of sea level rise
and subsidence (i.e., relative sea level rise), we used a 0.61-m (2-ft)
inundation scenario. A rise in sea level of this magnitude is predicted
to occur by about 2050 under a worst-case scenario (Boesch et al. 2013,
p. 15).
Our GIS analysis, in which we overlaid this inundation scenario
with DFS-occupied forest, indicated that the most severe effects of sea
level rise on the DFS by 2050 will be seen in the southwestern portion
of Dorchester County, Maryland (USFWS 2012, figure 12). Here, 9,332 ha
(23,060 ac) of currently occupied forest would either be lost or remain
only on isolated islands (USFWS 2012, figure 12). In addition, 4,409 ha
(10,897 ac) of habitat along the remaining southern edge of the county
would eventually deteriorate, causing DFSs to move inland. The ability
of DFSs to move into connected habitat likely reduces the effects on
this subspecies due to forest losses at the coastal marsh fringe; we
nonetheless recognize this as habitat loss. Other projected forest
losses include scattered patches throughout the range, including some
losses in the range of the Chincoteague population (USFWS 2012, figure
12).
Even if the predicted habitat losses from sea level rise in
southwestern Dorchester County were to occur immediately, the area's
remaining 23,632 ha (58,398 ac) of occupied habitat would continue to
support a highly abundant DFS population with a negligible risk of
extinction. Moreover, the habitat in the northeastern portion of this
area is connected to existing occupied forest farther inland (USFWS
2012, figure 9) into which DFSs could move. In particular, a large
tract of State-owned forest that will soon become sufficiently mature
to allow for DFS expansion connects the Dorchester DFS subpopulation to
forest tracts in Caroline and Sussex Counties (USFWS 2012, figure 10).
Although sea level rise may cause streams and rivers to widen and pose
more of a barrier in the future, forested corridors will still be
available to provide DFSs with access to habitat in the inland portions
of Dorchester County.
Given our current understanding of DFS habitat use, dispersal, and
population dynamics, the expected DFS response to deterioration of
coastal woodlands from sea level rise is the gradual movement of some
DFSs to more inland areas. The DFS is known to travel across areas of
marsh and can move at least 40 to 50 m (131 to 164 ft) between forested
islands and may also move across frozen marsh in the winter. We
acknowledge that despite the squirrel's ability to move, isolation and
loss of some individuals is likely to occur. Nonetheless, we conclude
that habitat loss due to sea level rise will not be a limiting factor
to the future viability of this subspecies.
The 0.61-m (2-ft) inundation scenario does not play out the same in
parts of the range outside southwestern Dorchester County. In the
series of small peninsulas in northwestern Dorchester County called the
``neck region,'' this scenario results in shrinkage of available
habitat but does not create islands, and leaves habitat for the DFS to
move into (USFWS 2012, figure 12). This is also the case in other
portions of the squirrel's range near the Chesapeake Bay and the
Atlantic Coast. Some additional small areas of occupied habitat may be
lost, but the gradual loss can be accommodated by shifts in DFS home
ranges to adjacent but currently unoccupied habitat.
The most coastal population of the DFS is a translocated population
introduced in 1968 to Chincoteague NWR, a barrier island in Virginia
that could be severely affected by sea level rise (National Wildlife
Federation 2008, p. 69). The refuge's draft Comprehensive Conservation
Plan (available at http://www.fws.gov/nwrs/threecolumn.aspx?id=2147550165) addresses this issue, and the refuge
may consider future land acquisitions on the Delmarva Peninsula
mainland. Chincoteague NWR will continue to manage for the DFS into the
future whether or not the subspecies remains listed. In addition,
translocations of DFSs to areas outside refuge boundaries at some point
in the future are possible.
It is not clear how climate change effects may alter the nature of
the forests of the Delmarva Peninsula. However, as the DFS occurs in
pine, hardwood, and mixed hardwood forests, with a preference for mixed
forests with diverse tree species, any effects on the species
composition of these forests are unlikely to become a significant
threat for the squirrel.
Overall, DFS distribution has increased in the past 40 years even
with
[[Page 70711]]
some sea level rise occurring. In the next 40 years under a worst-case
scenario, we predict some deterioration of forests in certain areas
along the Chesapeake Bay and the Atlantic Coast (USFWS 2012, figure
12), but we also anticipate population expansion and shifts in DFS home
ranges into suitable but currently unoccupied habitat available in the
interior of the Delmarva Peninsula. Although some concern has been
expressed about the likelihood of such expansion (e.g., by the Center
for Biological Diversity 2013), the analysis of habitat suitability,
connectivity, and the range expansion documented in the last 15 years
provides a rational basis for this expectation. Thus, available data
indicate that loss of habitat due to climate change and sea level rise
does not pose an extinction risk to the DFS.
Combined Effects of Development and Sea Level Rise
Having determined that neither development nor sea level alone
threatens the DFS with rangewide extinction, we conducted a spatial
analysis to examine how these most pervasive stressors might interact
(USFWS 2012, figure 5 and table 7).
As of 2010, 54,429 ha (134,496 ac) of habitat supported 22 DFS
subpopulations, (USFWS 2012, table 7), and 95 percent of the occupied
forest contains the 11 largest subpopulations, which are highly likely
to remain demographically viable. Even with projected losses from both
development and sea level rise, and not accounting for potential
discovery of additional occupied habitat, over 95 percent of the DFS-
occupied forest would continue to support these most viable
subpopulations. Thus, the combined effects of these threats do not pose
an extinction risk to the DFS.
Loss of Mature Forest From Timber Harvest
Unlike development and sea level rise, timber harvest does not
result in permanent loss of habitat. Further, as noted under Recovery
Criteria, above, DFSs are resilient to timber harvests when there is
adjacent habitat into which they can move. Thus, the major habitat
concerns related to timber harvests are (1) the prevalence of short-
rotation timber harvests, where trees are harvested before they mature
enough to become DFS habitat; and (2) harvest rates that exceed growth
rates and result in a continual decline of mature forest.
Short-rotation pine forestry involves harvesting stands at
approximately 25 years of age for pulp and other fiber products,
precluding their suitability as DFS habitat. In the past, two large
corporations managed for short-rotation pine on the Delmarva Peninsula;
however, these industries have effectively left the Peninsula. In 1999,
the State of Maryland acquired 23,471 ha (58,000 ac) of these lands,
collectively administered as the Chesapeake Forest Lands and comprising
scattered parcels throughout the southern four Maryland counties (USFWS
2012, figure 13). Another 4,202 ha (10,384 ac) of forest land
previously owned and managed for short-rotation pine are now owned by
the State of Delaware. All these lands will now be protected from
development and managed for sustainable sawtimber harvest and wildlife
habitat objectives. Moreover, DFS management has been integrated into
the Sustainable Forest Management Plan for Chesapeake Forest Lands
prepared by Maryland's Department of Natural Resources (Maryland DNR
2013, pp. 92-96), which identifies a total of 17,618 ha (43,535 ac) as
DFS Core Areas and DFS Future Core Areas. Overall, these land
acquisitions represent a future of protected forest areas managed for
sawtimber where the DFS can survive and grow in numbers, substantially
removing the threat posed by short-rotation pine management on the
lower Delmarva Peninsula.
Harvest rate estimates for both the 2007 and 2012 status review
(USFWS 2007, pp. 17-20; USFWS 2012, table 6) indicated that harvests in
more recent years have been substantially less than in previous years
(generally prior to 2005) (USFWS 2012, table 6). For instance, in the
four southern Maryland counties, the average annual harvest dropped
from approximately 1,050 ha (2,594 ac) prior to 2005, to approximately
303 ha (749 ac) since then. The average size of harvested stands in
these counties has also decreased, from an average of 22 ha (54 ac) to
an average of 15 ha (36 ac). This is also the case in Delaware; in
Sussex County, the annual harvest rate in the last 4 years was half of
what was generally harvested between 1998 and 2005, with the same
holding true for the size of individual harvest areas.
Among other reasons for these reductions, economic pressures have
resulted in the closure of several sawmills on the Delmarva Peninsula.
The market for timber has declined dramatically, with low prices acting
as a disincentive to harvesting. As discussed below, reduced harvest
levels are likely to continue in the future.
Although it is very difficult to predict future market forces,
trends in fragmentation and parcelization in the Chesapeake Bay region
(Sprague et al. 2006, pp. 22-24) suggest that future timber harvests
might remain smaller in size and occur less frequently. Parcelization
is the subdivision of large blocks of land into multiple ownerships,
with a consequent tendency to shift from forest management to
management for aesthetics and wildlife values. In Maryland, 45 percent
of woodland owners own less than 20 ha (50 ac) of woods (U.S.
Department of Agriculture, 2012). Given general sizes of timber
harvests, these woodlands may be too small for future harvests and are
more likely to be managed for aesthetics and wildlife.
This ownership pattern also reflects the gentrification of the
eastern shore of Maryland, with landowners becoming less likely to be
farmers or foresters and more likely to be commuters or retirees who do
not use their properties for income. This trend is expected to continue
into the future (see http://www.mdp.state.md.us/msdc/S3_Projection.shtml), with a concomitant reduction in total acres
harvested.
Overall, the forest land transfers in Maryland and Delaware, in
conjunction with available data on harvest rates across the range of
the squirrel, suggest that timber harvest does not pose an extinction
risk for the DFS.
Factor A Summary
The current range of the DFS spans coastal and interior areas of
the Delmarva Peninsula where DFSs inhabit diverse wetland and upland
forest types, suggesting that DFS populations will continue to remain
resilient to a variety of habitat-related effects. Further, the
distribution of these habitats provides for redundancy of populations,
which reduces the risk of catastrophic loss. We recognize that habitat
losses may occur in some areas, primarily from residential development
and sea level rise, but we expect the DFS population to remain at or
above recovered levels, and, moreover, we do not expect such habitat
losses to prevent overall expansion of the range in the future.
Factor B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
Overhunting has been posited as a factor in the original decline of
this subspecies. Squirrel hunting was common in the early and middle
decades of the 20th century, and hunting of the DFS in small, isolated
woodlots or narrow riparian corridors could have resulted in local
extirpations. Taylor (1976, p. 51) noted that the DFS remained present
on large agricultural estates where hunting was not allowed, suggesting
that these areas
[[Page 70712]]
may have provided a network of refugia for the DFS.
By 1972, hunting of DFS was banned through state regulations.
Removal of hunting pressure may have been one factor in the renewed
population growth and expansion of the squirrel's range to its current
extent. Coincidentally, squirrel hunting has declined in popularity in
recent decades; nationwide, squirrel hunting declined by about 40
percent between 1991 and 2001, and by an additional 20% between 2001
and 2011 (DOI 1991 p. 70; DOI 2001, p. 57; DOI 2011, p. 60). Recent
records of squirrel hunters specifically are not available for Maryland
but the number of small game hunters in Maryland (pursuing squirrels,
rabbits and/or quail) declined from 64,000 to 35,000 between 1991 and
2011 (DOI 1991, p. 113; DOI 2011, p. 102). Hunting gray squirrels will
continue to some extent, and though some hunters may mistake DFS for
gray squirrels, this is likely a rare situation that has not prevented
the DFS from expanding over the last 40 years.
Regarding hunting in the future, discussions with our State
partners indicate that DFS management after delisting would be
conducted very cautiously and that a hunting season would not be
initiated in the immediate future. We recognize that a restricted hunt
could be conducted at sites where DFSs are abundant without causing a
population decline, and that State management agencies have the
capability to implement careful hunting restrictions and population
management; the reopening of the black bear (Ursus americanus) hunt in
Maryland is a good example of a carefully and successfully managed hunt
(Maryland Department of Natural Resources 2012, entire).
We nonetheless foresee only limited individual interest in
reinitiating a DFS hunt, coupled with strong public attitudes against
hunting DFSs and, more generally, recreational hunting (Duda and Jones
2008, p. 183). Given public sentiment, the declining interest in
squirrel hunting, and the restrictions that we expect would be imposed
on a renewed hunting program, hunting is highly unlikely to pose an
extinction risk to the DFS in the foreseeable future.
Factor C. Disease or Predation
Each of these types of threat is summarized below.
Disease
Reports of disease in the DFS are uncommon. Although other
subspecies of eastern fox squirrels are known to carry diseases such as
mange and rabies, there is no documentation of these diseases in the
DFS, and there is no evidence or suspicion of disease-related declines
in any local population (USFWS 2012, pp. 37-38).
Although the advent of white-nose syndrome affecting bats (Blehert
et al. 2009, entire) and chytrid fungus affecting amphibians (Daszak et
al. 1999, entire) demonstrates the uncertainty surrounding novel
disease events, the life-history traits of the DFS tend to make them
less susceptible to these types of epizootics. Delmarva fox squirrels
do not congregate in large numbers where disease can easily spread
through a population. Further, the DFS is patchily distributed across
its range, which makes it more difficult for disease to spread across
populations, and DFSs are not migratory and do not inhabit the types of
environment (as with aquatic species) where pathogens can readily
disperse.
Overall, there currently is no evidence of disease-related declines
or any indication that DFSs are particularly susceptible to disease
outbreaks, and we conclude that disease is neither a current nor a
future extinction risk for this subspecies.
Predation
Predators of the DFS include the red fox (Vulpes vulpes), gray fox
(Urocyon cinereoargenteus), red-tailed hawk (Buteo jamaicensis), bald
eagle (Haliaeetus leucocephalus), and possibly domestic pets and feral
animals.
Changes in numbers of certain predators may cause some fluctuations
in DFS numbers at a site (for instance, a DFS population may decline
when red fox numbers increase), but these types of events are sporadic
and localized. Conversely, although bald eagle numbers have
dramatically increased in the Chesapeake Bay region over the past 40
years and eagles have been known to take DFSs, they still prey
primarily on fish. And while feral dogs and cats may occasionally take
DFSs, such predation is not a rangewide threat. The DFS population has
increased over the last 40 years despite ongoing predation, and we
conclude that predation at these levels is not a current or future
extinction risk for this subspecies.
Factor D. The Inadequacy of Existing Regulatory Mechanisms
Several laws established in Maryland over the past 40 years provide
substantial protections for DFS habitat (USFWS 2012, appendix D). The
Maryland Critical Areas Act of 1984 designates all areas within 304.8 m
(1,000 ft) of high tide as Critical Areas and, as amended, prohibits
development and forest clearing within 60.96 m (200 ft) of streams and
the Chesapeake Bay. These areas serve as both breeding habitat and
dispersal corridors for DFSs. The Maryland Forest Conservation Act of
1991 requires that when a forested area is cleared and converted to
other land uses, other forest areas must be protected in perpetuity or,
alternatively, replanted to offset these losses. Additionally, the
State-implemented portions of the Clean Water Act (33 U.S.C. 1251 et
seq.) provide rangewide protection to the many forested wetlands where
DFSs occur.
Several State programs in Maryland, including its Agricultural Land
Protection Fund, Environmental Trust, and Rural Legacy Program,
encourage voluntary conservation easements that protect lands from
development. Collectively, these programs now protect 79,066 ha
(195,377 ac) of private lands within the DFS' range. Similar programs
in Delaware protect an additional 12,677 ha (31,327 ac) in Sussex
County (USFWS 2012, table 3).
Although in Delaware and Virginia the DFS occurs primarily on
Federal and State lands, regulatory protections affecting private lands
allow for continued DFS range expansion. For example, Delaware's
Agricultural Land Protection Program and Forest Legacy Program now
protect more than 12,677 ha (31,327 ac) in Sussex County, much of which
is or could be occupied by the DFS. The Virginia DFS population is
completely protected on Chincoteague NWR. If needed, State-owned lands
or private lands, or both, protected by land trusts would provide
suitable habitat for future translocations.
Overall, many State laws and programs that protect the DFS and its
habitat have been enacted or strengthened in the last 40 years, and it
is likely that this State protection will continue. Currently, these
regulatory mechanisms, together with other factors that address
population and habitat trends, have substantially reduced threats to
the DFS. We thus conclude that existing regulatory mechanisms are
adequate in terms of reducing extinction risks for the DFS.
Factor E. Other Natural or Manmade Factors Affecting Its Continued
Existence
The level of risk posed by each of the following factors is
assessed below.
Forest Pest Infestations
Forest pest infestations can affect forest health and its ability
to provide suitable habitat for the DFS. Gypsy moth
[[Page 70713]]
(Lymantria dispar) outbreaks can decimate mature forest stands,
although the affected stands will eventually regenerate. Monitoring
outbreaks and spraying for gypsy moth control appear to have reduced
this threat within the current range of the DFS, as infestations in the
last several years have diminished in acreage (Maryland Department of
Agriculture Forest Health Highlights 2007, 2008, 2009; entire).
Southern pine bark beetle (Dendroctonus frontalis) infestations can
also decimate mature forest stands within the range of the DFS.
Although beetle outbreaks necessitated salvage cuts for a total of 809
ha (2,000 ac) scattered across the southern counties in Maryland in the
early 1990s, monitoring and control efforts appear to have reduced this
threat as well.
Overall, an analysis of forest pests in the Chesapeake Bay
watershed found that most areas on the Eastern Shore where DFSs occur
have a relatively low likelihood of insect infestations, with 3.8 to 10
percent of this area considered to be at risk (Sprague et al. 2006, p.
87). Although emergence of new forest pests is to be expected,
Maryland's Forest Health Monitoring Program conducts surveys to map and
report forest pest problems (Maryland Department of Agriculture, Forest
Pest Management, 2012, entire). Forest pest outbreaks are likely to
recur and may increase if the climate warms as projected; however, this
threat appears to be localized and sporadic and, with existing programs
to monitor and treat forest pest outbreaks, we conclude that this is
not an extinction risk factor for the DFS.
Vehicle Strikes
Vehicle strikes are a relatively common source of DFS mortality.
Similarly to other species, the probability of DFSs being hit by
vehicles is dependent on the DFS' density and proximity of roads to
habitat. Vehicle strikes of DFSs tend to be reported more frequently in
areas where DFSs are abundant, even if traffic levels are relatively
low (e.g., Dorchester County). The conscientious reporting and
collecting of DFSs killed on roads at the Blackwater and Chincoteague
NWRs, where the DFS is very abundant, likely results in a more complete
count of vehicle strikes than elsewhere. Vehicle strikes occur
regularly at both refuges, yet DFSs remain abundant in both places and
have expanded their occupancy at Chincoteague NWR.
Overall, most DFS populations across the subspecies' range continue
to remain stable or are increasing in numbers despite these localized
events, and we conclude that vehicle strikes alone are not a pervasive
threat or extinction factor for this subspecies.
Overall Summary of Factors A Through E
A summary of the five-factor analysis discussed above is provided
in Table 3. Based on our analysis, we conclude that no single factor or
combination of factors poses a risk of extinction to the DFS now or in
the foreseeable future.
Table 3--Summary of Five-Factor Analysis Under the Act for DFS
----------------------------------------------------------------------------------------------------------------
Does factor pose an
Factor Past trends Foreseeable trends extinction risk?
----------------------------------------------------------------------------------------------------------------
Habitat loss from development..... In the past 40 years, Development is projected No.
development increased to increase to 14
from 3 to 8 percent of percent of the land area
the land area in the in the Maryland and
Maryland range of the Delaware portions of
DFS; development also DFS' range. Although
increased in Sussex most development will
County, Delaware. Some occur near urban areas
habitat has been lost, where DFSs do not occur,
but most development 3 to 4 percent of total
occurs near existing DFS occupied habitat is
towns where DFSs are not expected to be affected.
as prevalent, and While these losses may
development often occurs cause some small
on agricultural rather subpopulations to
than forest land. disappear, most occupied
habitat will remain
available. Despite the
projected development,
DFS distribution is
expected to continue to
expand.
Habitat loss from sea level rise.. In the past, loss of Under an extreme scenario No.
occupied habitat due to of 0.61-m (2-ft)
inundation and saltwater inundation in 40 years,
intrusion has occurred in considerable acreage
southern Dorchester will be lost or isolated
County, although the in southwestern
acreage is not known. Sea Dorchester County.
level rise has occurred However, even if this
in the past at the rate loss were to occur
of 3.5 millimeters (mm) immediately, the
per year (about 1 ft per Dorchester County
100 years). subpopulation would
remain over 70 times
larger than the MVP. It
would thus continue to
be the largest
subpopulation, and given
a 40-year time frame for
reaching this level of
inundation, is very
likely to remain viable
over the long term.
Habitat loss from timber harvest.. Sawtimber harvest has Recent declines in timber No.
occurred throughout the harvests, along with
Delmarva Peninsula. Past mill closings, may
harvest rates appear to reduce the harvest rate
have been sustainable, as for some time.
DFSs have remained Increasing parcelization
present across the range. of land will further
reduce opportunities for
large-scale timber
production.
Gentrification of the
Eastern Shore is
shifting public values
for forest management
from timber production
to management for
aesthetics and wildlife.
Thus, future timber
harvest rates are not
expected to exceed past
harvest rates.
[[Page 70714]]
Habitat loss from short-rotation In the past, short- Since 1999, these lands No.
pine management. rotation pine harvests have been acquired by
occurred on approximately the States of Maryland
68,000 ac of the forest and Delaware and are now
lands in the Maryland and managed for sawtimber,
Delaware portions of the which will provide
DFS' range. These acres suitable DFS habitat.
were typically harvested Thus, 58,000 ac of land
before they were mature in Maryland and 10,000
enough to become DFS ac in Delaware are
habitat. protected from
development and managed
for sawtimber, enabling
future use by the DFS
that was previously
precluded.
Overutilization................... Hunting seasons have been Hunting seasons are No.
closed since 1972. likely to remain closed
into the foreseeable
future. If opened, DFS
hunts would be limited
and carefully managed.
Interest in squirrel
hunting has declined
significantly, and
public attitudes toward
hunting have changed to
primarily support
hunting of those species
viewed as needing
population management,
such as deer.
Disease or predation.............. Disease and predation have These threats are not No.
not been significant expected to increase,
threats for this and the expanding
subspecies in the past 40 distribution of the DFS
years. lessens the potential
impacts that disease and
predation could have on
this subspecies.
Inadequacy of regulatory Several new Maryland laws In the next 40 years, No.
mechanisms. have appeared in the last forest conservation
40 years to help conserve measures are expected to
forest areas that support continue, and the
the DFS. DFS occurrences programs that have begun
in Delaware and Virginia in Maryland are expected
are almost exclusively on to continue or increase
protected lands. as they have in the
past. Easement programs
that protect private
lands from development
have begun in Delaware
and Virginia and are
expected to increase in
the future as well.
Other natural or manmade factors.. Forest pests and vehicle Forest pests and vehicle No.
strikes have occurred in strikes are likely to
the past 40 years to some continue to some extent,
extent but have not but neither factor has
limited the expansion of limited growth of the
the DFS' distribution. subpopulations in the
past, nor are they
expected to do so in the
future. As DFS
populations increase in
density, vehicle strikes
could increase, as the
probability of a strike
is primarily a function
of animal abundance.
----------------------------------------------------------------------------------------------------------------
Determination
We have carefully assessed the best scientific and commercial
information available regarding past, present, and future threats to
the long-term viability of the DFS. The current range of the DFS spans
the northern and southern portions of the Delmarva Peninsula,
comprising all three States, and extends from coastal areas to the
interior of the Delmarva Peninsula. The DFS inhabits a variety of
forest types, from hardwood-dominated to pine-dominated forests and
from wetland to upland forests, indicating an underlying genetic
variability or behavioral plasticity that should enhance the
subspecies' ability to adapt to changing environmental conditions. Its
relatively wide distribution also provides redundancy of occupied
forest across the landscape, which further reduces extinction risk, and
its continued occupancy of woodlots over the past 20 to 30 years and
the success of translocation efforts indicate considerable resilience
to stochastic events. We thus expect the rangewide population of the
DFS not only to remain at recovery levels but to grow and continue to
occupy the full complement of landscapes and forest types on the
Delmarva Peninsula.
The Act defines ``endangered species'' as any species that is ``in
danger of extinction throughout all or a significant portion of its
range,'' and ``threatened species'' as any species that is ``likely to
become an endangered species within the foreseeable future throughout
all or a significant portion of its range.'' The term ``species''
includes ``any subspecies of fish or wildlife or plants, and any
distinct population segment [DPS] of any species of vertebrate fish or
wildlife which interbreeds when mature.'' As a subspecies, the DFS has
both met the recovery criteria we consider for delisting, and the
analysis of existing and potential risks shows that the range and
distribution of the subspecies is sufficient to withstand all
foreseeable threats to its long-term viability. Thus, after assessing
the best available information, we have determined that the DFS is no
longer in danger of extinction throughout all of its range, nor is it
likely to become threatened with endangerment in the foreseeable
future.
Significant Portion of the Range Analysis
Overview
Having determined the status of the DFS throughout all of its
range, we next examine whether the subspecies is in danger of
extinction in a significant portion of its range. Under the Act and our
implementing regulations, a species may warrant listing if it is in
danger of extinction or likely to become so throughout all or a
significant portion of its range, as stated above. We published a final
policy interpreting the phrase ``significant portion of its range'' (79
FR 37578; July 1, 2014). This policy states that: (1) If a species is
found to be endangered or threatened throughout a significant portion
of its range, the entire species is listed as an endangered species or
a threatened species,
[[Page 70715]]
respectively, and the Act's protections apply to all individuals of the
species wherever found; (2) a portion of the range of a species is
``significant'' if the species is not currently endangered or
threatened throughout all of its range, but the portion's contribution
to the viability of the species is so important that, without the
members in that portion, the species would be in danger of extinction
or likely to become so in the foreseeable future throughout all of its
range; (3) the range of a species is considered to be the general
geographical area within which that species can be found at the time we
make any particular status determination; and (4) if a vertebrate
species is endangered or threatened throughout an SPR, and if it can
also be shown the population in that significant portion is a valid
DPS, we will list the DPS rather than the entire taxonomic species or
subspecies.
The SPR policy is applied to all status determinations, including
analyses for the purposes of making listing, delisting, and
reclassification determinations. The procedure for analyzing whether
any portion is an SPR is similar, regardless of the type of status
determination we are making. The first step in our analysis of the
status of a species is to determine its status throughout all of its
range. If we determine that the species is in danger of extinction, or
likely to become so in the foreseeable future, throughout all of its
range, we list the species as an endangered (or threatened) species and
no SPR analysis will be required. If the species is neither in danger
of extinction, nor likely to become so, throughout all of its range, we
determine whether the species is in danger of extinction or likely to
become so throughout a significant portion of its range. If it is, we
list the species as an endangered species or a threatened species,
respectively; if it is not, we conclude that listing of the species is
not warranted.
When we conduct an SPR analysis, we first identify any portions of
the species' range that warrant further consideration. The range of a
species can theoretically be divided into portions in an infinite
number of ways. However, there is no purpose to analyzing portions of
the range that are not reasonably likely to be both significant and
endangered or threatened. To identify only those portions that warrant
further consideration, we determine whether there is substantial
information indicating that (1) the portions may be significant and (2)
the species may be in danger of extinction in those portions or likely
to become so within the foreseeable future. We emphasize that answering
these questions in the affirmative is not a determination that the
species is endangered or threatened throughout a significant portion of
its range--rather, it is a step in determining whether a more detailed
analysis of the issue is required. In practice, a key part of this
analysis is whether the threats are geographically concentrated in some
way. If the threats to the species are affecting it uniformly
throughout its range, no portion is likely to warrant further
consideration. Moreover, if any concentration of threats apply only to
portions of the range that clearly do not meet the biologically based
definition of ``significant'' (i.e., the loss of that portion clearly
would not be expected to increase the vulnerability to extinction of
the entire species), those portions will not warrant further
consideration.
If we identify any portions that may be both (1) significant and
(2) endangered or threatened, we engage in a more detailed analysis to
determine whether these standards are indeed met. The identification of
an SPR does not create a presumption, prejudgment, or other
determination as to whether the species in that identified SPR is
endangered or threatened. We must go through a separate analysis to
determine whether the species is endangered or threatened in the SPR.
To determine whether a species is endangered or threatened throughout
an SPR, we will use the same standards and methodology that we use to
determine if a species is endangered or threatened throughout its
range.
Depending on the biology of the species, its range, and the threats
it faces, it may be more efficient to address the ``significant''
question first, or the status question first. Thus, if we determine
that a portion of the range is not ``significant,'' we do not need to
determine whether the species is endangered or threatened there.
Conversely, if we determine that the species is not endangered or
threatened in a portion of its range, we do not need to determine if
that portion is ``significant.''
SPR Analysis for DFS
Having determined that the DFS does not meet the definition of
endangered or threatened throughout its range, we considered whether
there are any significant portions of its range in which it is in
danger of extinction or likely to become so. The full discussion
regarding this analysis, summarized here, is provided in the September
23, 2014, proposed rule (79 FR 56686).
Applying the process described above, we evaluated the range of the
DFS to determine if any area could be considered a significant portion
of its range. Based on examination of the relevant information on the
biology and life history of the DFS, we determined that there are no
separate areas of the range that are significantly different from
others or that are likely to be of greater biological or conservation
importance than any other areas. We next examined whether any threats
are geographically concentrated in some way that would indicate the
subspecies could be in danger of extinction, or likely to become so, in
that area. Through our review of threats to the subspecies, we
identified some areas where DFSs are likely to be extirpated, including
areas in Queen Anne's County, Maryland, where DFS distribution is
scattered and relatively isolated by roads and water, and where future
development is anticipated. We thus considered whether this area in the
northern portion of the range may warrant further consideration as a
significant portion of its range.
The forest area currently occupied by DFSs that is projected to be
lost to development by 2030 would affect two small populations in Queen
Anne's County that together constitute less than 0.5 percent of the
rangewide population; however, five large DFS subpopulations are
expected to remain viable across the northern portion of the current
range. Additionally, Queen Anne's County's landscape does not represent
a unique habitat type or ecological setting for the subspecies. Thus,
the areas expected to be lost due to development would not appreciably
reduce the long-term viability of the subpopulation in the northern
portion of the range, much less imperil the DFS in the remainder of its
range. Therefore, we have determined that this portion of the DFS'
range does not meet the definition of SPR under the 2014 policy.
We also anticipate loss of DFS-occupied forests from sea level rise
in Dorchester County, Maryland, on the southwestern periphery of the
habitat supporting the largest subpopulation of DFS. However, these
losses do not threaten either the subpopulation or the subspecies with
a risk of extinction, as there is ample unoccupied and sufficiently
connected habitat for displaced squirrels to colonize; this is
bolstered by their ability to readily colonize new areas evidenced by
successful expansion of DFS translocations. In addition, we anticipate
the continued presence of mixed pine/hardwood forests adjacent to marsh
and open water in Dorchester
[[Page 70716]]
County and do not anticipate losses of any unique habitats. Therefore,
losses due to sea level rise in this portion of the range would not
appreciably reduce the long-term viability of the subpopulation, much
less cause the subspecies in the remainder of its range to be in danger
of extinction or likely to become so. We thus conclude the portion of
the range that is expected to be lost from sea level rise does not meet
the policy's definition of an SPR.
These are the only two portions of the range that we identified as
meriting analysis as to their significance and level of endangerment in
conformance with the 2014 SPR policy. Finding that the potential losses
in small areas of Queen Anne's County would not cause cascading
vulnerability and do not constitute unique areas that are not
represented elsewhere in the subspecies' range, and finding that loss
of areas in Dorchester County to sea level rise would not diminish the
continued viability of the Dorchester subpopulation or cause the
remainder of the subspecies to be in danger of extinction or likely to
become so, we do not consider this subspecies to be endangered or
threatened in any significant portion of its range. Further, having not
found the basis for an SPR determination on grounds of either
significance or threat, we also find that a DPS analysis is not
warranted.
Summary
The subspecies' current and projected resiliency, redundancy, and
representation should enable it to remain at recovered population
levels throughout all of its range, and even expand its range, over the
foreseeable future. Having assessed the best scientific and commercial
data available and determined that the DFS is no longer endangered or
threatened throughout all or a significant portion of its range and is
not it likely to become so in the foreseeable future, we are removing
this subspecies from the List under the Act.
Future Conservation Measures
Section 4(g)(1) of the Act requires us, in cooperation with the
States, to implement a monitoring program for not less than 5 years for
all species that have been recovered and delisted. The purpose of post-
delisting monitoring (PDM) is to verify that a species remains secure
from risk of extinction after the protections of the Act are removed by
developing a program that detects the failure of any delisted species
to sustain itself. If, at any time during the monitoring period, data
indicate that protective status under the Act should be reinstated, we
can initiate listing procedures, including, if appropriate, emergency
listing under section 4(b)(7) of the Act.
This rule announces availability of the final PDM plan for the DFS.
Public and peer review comments on the draft PDM plan have been
addressed in the body of the plan and are summarized in the plan's
appendix. The plan can be accessed at: http://www.regulations.gov under
Docket No. FWS-R5-ES-2014-0021. It is also posted on the Service's
national Web site (http://endangered.fws.gov) and the Chesapeake Bay
Field Office's Web site (http://www.fws.gov/chesapeakebay). A summary
of the PDM plan is provided below.
Post-Delisting Monitoring Plan Overview
The PDM plan for the DFS builds upon and continues the research
conducted while the DFS was listed. In general, the plan directs the
Service and State natural resource agencies to (1) continue to map all
DFS sightings and occupied forest to delineate the distribution and
range, and (2) assess the occupancy of DFS in a sample of forest tracts
to estimate the relative persistence of DFS populations versus
extirpations across the range.
The PDM plan identifies measurable management thresholds and
responses for detecting and reacting to significant changes in the
DFS's protected habitat, distribution, and ability to remain at
recovered population levels. If declines are detected equaling or
exceeding these thresholds, the Service, along with other post-
delisting monitoring participants, will investigate causes, including
consideration of habitat changes, stochastic events, or any other
significant evidence. Results will be used to determine if the DFS
warrants expanded monitoring, additional research, additional habitat
protection, or resumption of Federal protection under the Act.
Effects of This Rule
This final rule revises 50 CFR 17.11(h) to remove the Delmarva
Peninsula fox squirrel from the List of Endangered and Threatened
Wildlife (List). It also revises 50 CFR 17.11(h) and 50 CFR 17.84(a) to
remove the listing and regulations, respectively, for the nonessential
experimental population of Delmarva Peninsula fox squirrels at
Assawoman Wildlife Management Area in Sussex County, Delaware. The
prohibitions and conservation measures provided by the Act,
particularly through sections 7 and 9, no longer apply to this
subspecies. Federal agencies are no longer required to consult with the
Service under section 7 of the Act in the event that activities they
authorize, fund, or carry out may affect the DFS. The take exceptions
identified in 50 CFR 17.84(a)(2) for the experimental population of the
DFS are also removed. There is no critical habitat designated for the
DFS.
Required Determinations
National Environmental Policy Act
We have determined that environmental assessments and environmental
impact statements, as defined under the authority of the National
Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.), need not be
prepared in connection with regulations pursuant to section 4(a) of the
Act. We published a notice outlining our reasons for this determination
in the Federal Register on October 25, 1983 (48 FR 49244).
Government-to-Government Relationship With Tribes
In accordance with the President's memorandum of April 29, 1994,
``Government-to-Government Relations with Native American Tribal
Governments'' (59 FR 22951), Executive Order 13175, and the Department
of the Interior's manual at 512 DM 2, we readily acknowledge our tribal
trust responsibilities. We have determined that there are no tribal
lands affected by this rule.
References Cited
A complete list of all references cited in this final rule is
available at http://www.regulations.gov, or upon request from the
Chesapeake Bay Field Office (see ADDRESSES).
Authors
The primary authors of this final rule are staff members of the
Chesapeake Bay Field Office (see ADDRESSES).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Regulation Promulgation
Accordingly, we amend part 17, subchapter B of chapter I, title 50
of the Code of Federal Regulations, as set forth below:
PART 17--ENDANGERED AND THREATENED WILDLIFE AND PLANTS
0
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 1531-1544; 4201-4245, unless
otherwise noted.
[[Page 70717]]
Sec. 17.11--[Amended]
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2. Amend Sec. 17.11(h) by removing both entries for ``Squirrel,
Delmarva Peninsula fox'' under MAMMALS from the List of Endangered and
Threatened Wildlife.
Sec. 17.84--[Amended]
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3. Amend Sec. 17.84 by removing and reserving paragraph (a).
Dated: October 23, 2015.
James W. Kurth,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 2015-28742 Filed 11-13-15; 8:45 am]
BILLING CODE 4333-15-P