[Federal Register Volume 63, Number 203 (Wednesday, October 21, 1998)]
[Proposed Rules]
[Pages 56128-56134]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-28189]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
RIN 1018-AF00
Endangered and Threatened Wildlife and Plants; Proposed Rule To
Delist the Dismal Swamp Southeastern Shrew (Sorex longirostris fisheri)
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Proposed rule.
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SUMMARY: The U.S. Fish and Wildlife Service (Service) proposes to
remove the Dismal Swamp southeastern shrew (Sorex longirostris fisheri
Merriam) from the List of Endangered and Threatened Wildlife. The
Dismal Swamp southeastern shrew was listed as a threatened species in
1986 under the Endangered Species Act of 1973, as amended (Act). New
data indicate that this species is more widely distributed than
previously believed, is fairly abundant within its range, occurs in a
wide variety of habitats, and is genetically secure. The Service
concludes that the data supporting the original classification were
incomplete and that the new data indicate removing the Dismal Swamp
southeastern shrew from the List of Endangered and Threatened Wildlife
is warranted.
DATES: Comments from all interested parties must be received by
December 21, 1998. Public hearing requests must be received by December
7, 1998.
ADDRESSES: Comments and materials concerning this proposal should be
sent to the Virginia Field Office, U.S. Fish and Wildlife Service, P.O.
Box 99, 6669 Short Lane, Gloucester, Virginia 23061. The complete file
for this rule is available for inspection by appointment, during normal
business hours at the above address.
FOR FURTHER INFORMATION CONTACT: Cynthia A. Schulz, Fish and Wildlife
Biologist, at the above address (telephone 804/693-6694, extension 127;
facsimile 804/693-9032).
SUPPLEMENTARY INFORMATION:
Background
The Dismal Swamp southeastern shrew is a small, long-tailed shrew
with a brown back, slightly paler underparts, buffy feet, and a
relatively short, broad nose (Handley 1979a). It weighs 3 to 5 grams
and measures up to 10 centimeters in length. The species was first
described as Sorex fisheri by C.H. Merriam (Merriam 1895). Merriam's
description was based on four specimens trapped near Lake Drummond,
Virginia by A.K. Fisher of the U.S. Department of Agriculture's Bureau
of Biological Surveys. Rhoads and Young (1897) captured a specimen in
Chapanoke, Perquimans County, North Carolina, that seemed intermediate
between S. fisheri and the southeastern shrew (Sorex longirostris
Bachman) (Handley 1979b). Jackson (1928) subsequently reduced S.
fisheri to a subspecies of S. longirostris. Three subspecies of
southeastern shrew are now recognized--Sorex longirostris eionis, which
occurs in the northern two-thirds of peninsular Florida (Jones et al.
1991); S. l. fisheri, which occurs in southeastern Virginia and eastern
North Carolina; and S. l. longirostris, which occurs in the rest of the
range that extends through eastern Louisiana, eastern Oklahoma, and
Missouri, then eastward through central Illinois and Indiana, southern
Ohio, and Maryland. Jones et al. (1991) examined the taxonomic status
of these three subspecies and verified substantial size differences
among them. The authors found that S. l. eionis was significantly
larger in four cranial measurements when compared with the other two
subspecies; S. l. fisheri was significantly large in one cranial and
one external measurement; and S. l. longirostris had a relatively short
palate and rostrum, narrow skull, and short foot and tail. This study
confirmed the subspecific status of S. l. fisheri.
Apart from a litter of five young found in a nest in the Dismal
Swamp in 1905, little is known about reproduction or other life history
features of Sorex longirostris fisheri (Handley 1979b). However, more
is known about the life history of other Sorex species, and this
information may apply to S. l. fisheri. Sorex longirostris reproduces
from March through October, and it is likely that two litters are born
each year, with one to six young produced per litter (Webster et al.
1985). Nests are shallow depressions lined with dried leaves and
[[Page 56129]]
grasses and are usually associated with rotting logs (Webster et al.
1985). Young shrews grow rapidly and are almost adult size when they
leave the nest (Jackson 1928). Sorex longirostris forage on spiders,
crickets, butterfly and moth larvae, slugs, snails, beetles,
centipedes, and vegetation (Webster et al. 1985, Whitaker and Mumford
1972). Little information is available about the daily activity
patterns of S. longirostris. They forage intermittently throughout the
day and night in all seasons, seem to be most active after rains and
during periods of high humidity, and do much of their foraging in the
leaf litter or in tunnels in the upper layers of the soil (Jackson
1928).
The Dismal Swamp, the type locality for Sorex longirostris fisheri,
is a forested wetland with a mosaic of habitat types located in
southeastern Virginia and adjacent North Carolina. Within the Dismal
Swamp, S. l. fisheri has been found in a variety of habitat types
including recent clearcuts, regenerating forests, young pine
plantations, grassy and brushy roadsides, young forests with shrubs and
saplings, and mature pine and deciduous forests (Padgett 1991, Rose
1983). Sorex longirostris fisheri has also been collected in utility
line rights-of-way. The highest densities of S. l. fisheri occur in
early successional stage habitats and the lowest densities in mature
forests (Everton 1985), although mature forests are likely to be
important to the survival of the shrew during periods of drought or
fire. Densities of southeastern shrews in early successional stages are
10 to 30 per hectare (Rose 1995). Rose (1995) stated that, based on his
previous studies, mature forests yield only about \1/4\ or less of the
densities of S. longirostris compared with early successional stage
habitats dominated by grasses and shrubs. Mature forests with closed
canopies have densities of one to four shrews per hectare (Rose 1995).
``Within two years of the cutting of a forest plot, and probably for 8-
12 years afterwards on such cutover plots, the densities of
southeastern shrews are likely to be five or more times greater than in
nearby mature forests. (The number of years depends, in part, on
whether the trees on the sites regenerate naturally or are planted.)''
(Rose 1995).
Until recently, the distribution of Sorex longirostris fisheri was
considered coincidental with the historical boundaries of the Dismal
Swamp (Handley 1979a, Hall 1981, Rose 1983). After collection of the
original type series, additional S. l. fisheri specimens were collected
from similar habitats in the Dismal Swamp between 1895 and 1902. Prior
to 1980, only 19 specimens of S. l. fisheri were known. ``In addition
to Young's (Rhoads and Young 1989) Chapanoke specimen in the Academy of
Natural Sciences of Philadelphia, and one in the American Museum of
Natural History that (W. J.) Daniel (Jr.) collected at Lake Drummond in
1905, the National Museum has 16 from Lake Drummond collected in 1895
and 1902 by Fisher, T. S. Palmer, (W. L.) Ralph, and Daniel, and one I
collected near Wallaceton (at the eastern edge of the Dismal Swamp in
Virginia) in 1953'' (Handley 1979b). In 1980, 15 S. longirostris were
collected in pitfall traps in Suffolk, Virginia from the northwest
section of the Great Dismal Swamp National Wildlife Refuge (Refuge)
(Rose 1981) that is located in North Carolina and Virginia. Based on
their large size, the specimens were classified as S. l. fisheri.
From December 1980 through July 1982, 37 pitfall grids were
established in Currituck and Gates counties, North Carolina and the
Cities of Chesapeake, Suffolk, and Virginia Beach and Isle of Wight and
Surry counties, Virginia (Rose 1983). The results of this trapping were
24 specimens from 10 populations classified as Sorex longirostris
fisheri, 62 specimens from 9 populations classified as intergrades, and
30 specimens from 7 populations classified as S. l. longirostris. Three
grids each contained one specimen classified as S. l. longirostris,
while the remaining specimens were classified as S. l. fisheri. The
author determined that S. l. fisheri was associated with the Dismal
Swamp proper, except for a population north of the Refuge and a
population east of the Refuge. A narrow zone of hybridization (these
populations contained specimens that represent the parent stocks and
individuals that may be hybrids) was found to border the Dismal Swamp
running approximately north/south along its western edge and running
northwest/southeast adjacent to the southeastern corner of the Refuge.
Sorex longirostris longirostris was found to the east and west of the
Dismal Swamp with distinctive populations of S. l. longirostris
occurring within 20 miles of the Dismal Swamp border (Rose 1983). The
results of this analysis indicated that the largest Sorex were located
within the Refuge and the smallest Sorex were located at greater
distances from the Refuge, with specimens of intermediate size on the
margins of the Refuge. This suggested that interbreeding of the two
subspecies might be occurring, particularly at the margins of the
Refuge. Rose (1983) tentatively recommended that S. l. fisheri be
listed as threatened primarily because of the potential for contact and
interbreeding with S. l. longirostris. ``If widespread, this
interbreeding can result in an alteration of the gene pools of both
subspecies in the zone of contact, and the integrity of both subspecies
may be lost in the extreme'' (Rose 1983).
Additional study of Sorex was conducted from October 1986 through
June 1989, focusing within the Refuge but also including outlying areas
of the historical Dismal Swamp (Padgett 1991). Particular emphasis was
placed on determining whether the nominate subspecies might be
expanding into the remaining Dismal Swamp proper and interbreeding with
Sorex longirostris fisheri. The results of Padgett's (1991) study
indicated that S. l. fisheri was restricted to the historic Dismal
Swamp and that there was no strong evidence that S. l. longirostris was
using roadways to enter the interior of the Refuge. Between 1989 and
1991, Erdle and Pagels (1991) collected shrews to further delineate the
distributions of S. l. fisheri and S. l. longirostris in Virginia.
Sampling was conducted in much of the historic Dismal Swamp east of the
Refuge and north of the Virginia-North Carolina State line. Shrews
referable to both taxa and intergrades were represented in the 26 Sorex
trapped. These findings supported the hypothesis that S. l.
longirostris might be moving into areas of the historical Dismal Swamp.
During the 1990s, many additional areas were surveyed within the
historical Dismal Swamp in Virginia; the specimens found were referable
to S. l. fisheri or S. l. longirostris or were of intermediate size.
While a significant amount of study on the distribution of Sorex
longirostris fisheri had taken place in Virginia, knowledge of the
species in North Carolina was sparse. In the early 1980s, D. W. Webster
from the University of North Carolina-Wilmington collected Sorex
longirostris from southeastern North Carolina (D.W. Webster, University
of North Carolina-Wilmington, pers. comm. 1997). Utilizing the existing
range maps for S. longirostris, Webster determined that the specimens
were S. l. longirostris. In the late 1980s, Webster collected S.
longirostris from Beaufort County, North Carolina (located midway along
the coast of North Carolina) and realized that those specimens looked
just like those collected from southeastern North Carolina. Webster
(pers. comm. 1997), still using the existing range maps, assumed these
specimens were S. l. longirostris. Historical locations of S. l.
fisheri in North Carolina were
[[Page 56130]]
summarized by Webster (1992), indicating collection of S. l. fisheri
from Camden, Currituck, and Gates counties. Webster (1992) indicated
that S. l. fisheri probably inhabits parts of Chowan, Pasquotank, and
Perquimans counties. Webster continued to collect shrews from coastal
North Carolina throughout the early 1990s (D.W. Webster, pers. comm.
1997).
In January 1994, Webster visited the National Museum of Natural
History and compared specimens he had collected from southeastern North
Carolina and Beaufort and Gates counties, North Carolina, to the
specimens at the Smithsonian and realized that his specimens were of
the same size as the voucher specimen for Sorex longirostris fisheri
from Lake Drummond (the type locality). Charles O. Handley, curator of
mammals for the museum, agreed with Webster that these shrews were
referable to S. l. fisheri based on size. Based on that information,
Webster hypothesized that the ``dividing line'' between S. l. fisheri
and S. l. longirostris may be somewhere between Wilmington, North
Carolina and Charleston, South Carolina.
In May 1994, Webster visited the North Carolina State Museum of
Natural Sciences and found a series of relatively large Sorex
longirostris (not identified to subspecies) from Croatan National
Forest (Jones, Craven, and Carteret counties) in North Carolina (U.S.
Fish and Wildlife Service 1995). He presumed that this series of shrews
was S. l. fisheri based on his trip to the Smithsonian (D.W. Webster,
pers. comm. 1997). The State museum also had specimens of southeastern
shrews from Chowan, Bladen, and Brunswick counties that Webster assumed
were S. l. fisheri (D.W. Webster, pers. comm. 1997). In May and June
1994, Webster collected S. longirostris near the town of Warsaw in
Duplin County, midway between Wilmington and Raleigh, North Carolina.
He determined that these specimens were referable to S. l. fisheri
(D.W. Webster, pers. comm. 1997).
Webster et al. (1996a, 1996b) compared Sorex longirostris specimens
from east-central and southeastern North Carolina to specimens from the
Dismal Swamp. They also examined specimens from Charleston County,
South Carolina (near the type locality for S. l. longirostris) and
Citrus County, Florida (the type locality for S. l. eionis), and
representative samples of S. longirostris from throughout the
southeastern U.S. They concluded that S. l. fisheri ``is much more
widespread and ubiquitous than previously believed. From this, it was
determined that morphometric characteristics would be used to better
delineate the geographic distribution of S. l. fisheri in Virginia and
North Carolina. The morphometric analysis used 626 S. longirostris from
the southeastern U.S. (15 from Florida, 375 from North Carolina, 159
from Virginia, and the remaining 77 from Alabama, District of Columbia,
Indiana, Kentucky, Maryland, Mississippi, Missouri, South Carolina, and
Tennessee). The morphometric analysis included six cranial
measurements, palatal length, and braincase length. If available from
specimen tags, the total specimen length, tail length, hind foot
length, and weight were also utilized. Head and body length or the
difference between total length and tail length were determined where
possible. There was significant geographic variation in all cranial
measurements; samples from southeastern Virginia, eastern North
Carolina, and southern Georgia and Florida had much larger cranial
characteristics than samples from elsewhere in the range. The
significant geographic variation in external measurements and weight
typically followed the same pattern. A two-dimensional plot of the
samples formed three clusters: (1) shrews from Georgia and Florida that
have longer and overall much wider crania; (2) shrews from southeastern
Virginia and eastern North Carolina that have longer crania with
relatively narrower rostra; and (3) shrews from elsewhere in the range
that were smaller in all cranial measurements. This plot explained 93.2
percent of the total morphometric variation exhibited in S.
longirostris crania. Shrews from the piedmont and mountains of Virginia
and North Carolina were more similar to specimens from the Mississippi
and Ohio River basins than they were to those from the mid-Atlantic
coast.
Webster et al. (1996a, 1996b) established 84 survey sites in a wide
range of habitats throughout North Carolina and Virginia to ensure that
both Sorex longirostris longirostris and S. l. fisheri would be
captured. Of the 84 sites, 49 (58.3 percent) were located in abandoned
fields and powerline rights-of-way that were dominated by herbaceous
vegetation typical of early stages of succession. The other 35 sites
(41.7 percent) were dominated by arborescent vegetation, including such
forest types as longleaf pine/turkey oak, pocosin/bay, Atlantic white
cedar, shortleaf pine, riparian hardwood, and cove hardwood. Eighteen
species of small mammals were collected and S. longirostris was the
most abundant and ubiquitous. When survey sites were divided into two
groups, those occurring in the newly delineated range of S. l. fisheri
or in that of S. l. longirostris, the results were similar. Within its
geographic distribution, S. l. fisheri was the most abundant small
mammal, or shared that distinction with other species at 31 of the 84
sites sampled. Sorex longirostris fisheri was especially abundant in
forested habitats in and adjacent to the Refuge, comprising 84 percent
of the specimens taken. The only habitat sampled where S. l. fisheri
was absent was xeric longleaf pine/turkey oak. Both taxa were found in
a wide range of habitat types and moisture regimes, from early
successional to mature second-growth forest and from well-drained
uplands to seasonally-inundated wetlands. Webster (1996a, 1996b)
concluded that ``* * * even the smallest specimens from relatively dry,
upland sites in the Dismal Swamp region clearly are assignable to S. l.
fisheri.
Gurshaw (1996) examined allozyme variability in specimens of the
southeastern shrew from North Carolina and Virginia to identify
characters that differentiate Sorex longirostris fisheri and S. l.
longirostris and to determine if there are similarities between shrews
from the Dismal Swamp region and the coastal plain of southeastern
North Carolina. She found that shrews from the coastal plain of
southeastern North Carolina grouped most closely with those from the
Dismal Swamp. The author found an allele in the shrews from the coastal
plain that represents a genetic distinction from S. l. longirostris.
Distribution of this allele appeared to follow the Fall Line, the
boundary between the piedmont plateau and upper coastal plain in the
southeastern U.S.
Webster et al. (1996a, 1996b) concluded that Sorex longirostris
fisheri ``* * * has a much broader geographic distribution than
previously believed, extending from southeastern Virginia to
southeastern North Carolina along the outer coastal plain. In Virginia,
all specimens examined from Isle of Wight County, the City of
Chesapeake, and the City of Virginia Beach are referable to S. l.
fisheri, whereas those from Surry, Sussex, and Southampton counties are
assignable to S. l. longirostris. In North Carolina, S. l. fisheri is
distributed throughout the coastal counties as far south as New
Hanover, Brunswick, and Columbus Counties.'' Since the conclusion of
that study, S. l. fisheri has been documented in Hyde County, North
Carolina (D.W. Webster, pers. comm. 1997). No trapping for S.
longirostris has been conducted in Onslow, Martin, Pamlico, or Burtie
[[Page 56131]]
Counties, North Carolina (D.W. Webster, pers. comm. 1997). Webster
(pers. comm. 1997) does not have any records of S. l. fisheri from
Pasquotank County, although surveys were conducted there in 1995. At
the time of listing, Pasquotank County was listed as a county of
occurrence for S. l. fisheri, however, the literature cited does not
support this.
At the time of listing, Sorex longirostris fisheri was believed to
occur in only two cities in Virginia and four counties in North
Carolina. Sorex longirostris fisheri is now known to occur in Beaufort,
Bladen, Brunswick, Camden, Cateret, Chowan, Columbus, Craven,
Currituck, Dare, Duplin, Gates, Greene, Hyde, Jones, Lenoir, New
Hanover, Pender, Perquimans, Robeson, Scotland, Tyrrell, and Washington
counties in North Carolina and Chesapeake, Suffolk, and Virginia Beach
cities and Isle of Wight County in Virginia. Information gaps still
exist in the distribution of S. l. fisheri in North Carolina and
potentially South Carolina. Jones et al. (1991) noted a sample of Sorex
specimens from coastal South Carolina that appeared to be similar to S.
l. fisheri, but substantiation is needed regarding the taxonomy of
these specimens.
Previous Federal Action
On December 30, 1982, during its review of Vertebrate Wildlife (47
FR 58454), the Service designated the Dismal Swamp southeastern shrew
as a category 2 candidate species, meaning that a proposal to list the
subspecies as threatened or endangered was possibly appropriate, but
that substantial biological data were not available at that time to
support such a proposal. Rose (1981, 1983) and Everton (1985) conducted
pre-listing status surveys that documented large shrews within the
Refuge, small shrews outside the Refuge, and intermediate-sized shrews
near the Refuge boundaries.
On July 16, 1985, the Service published a proposed rule to list the
Dismal Swamp southeastern shrew as a threatened species (50 FR 28821).
The final rule to list the species was published in the Federal
Register on September 26, 1986 (51 FR 34422), and became effective on
October 27, 1986. The reasons for listing the Dismal Swamp southeastern
shrew were habitat loss and alteration and possible loss of genetic
integrity through interbreeding with S. l. longirostris.
In the early 1990's, a group of biologists from Virginia held
meetings to discuss information and issues related to the recovery of
the Dismal Swamp southeastern shrew. Initially, most of the effort was
focused in Virginia because of the development pressure occurring
there. In 1992, biologists from North Carolina were included in the
group. The Service then convened an official recovery team, and the
first meeting was held in February 1993.
A draft recovery plan was completed in July 1994, and a notice of
availability of the plan was published in the Federal Register (59 FR
37260). The recovery plan was finalized on September 9, 1994, and
updated on June 13, 1995.
Based on questions raised by D.W. Webster, a member of the recovery
team, about the shrew's distribution and taxonomy, in March 1995,
studies were funded by the Virginia Department of Game and Inland
Fisheries and the Service to determine if large shrews are distributed
from the Dismal Swamp region southward throughout the coastal plain of
North Carolina, and if the large shrews from coastal North Carolina are
similar to S. l. fisheri from near the type locality. A combination of
morphometric and genetic analyses was proposed to answer these
questions. The results of the morphological and genetic analyses which
followed are discussed in detail in the ``Background'' section of this
rule.
In May 1996, reports on morphometric variation among the three
Sorex longirostris subspecies (Webster et al. 1996a) and protein
electrophoresis and allozymic variation between S. l. fisheri and S. l.
longirostris (Gurshaw 1996) were received by the Service and sent to
the recovery team members. The recovery team convened in June 1996 to
discuss the two reports. The consensus of the team was that the results
of both the morphological and genetic analyses conclusively show that
S. l. fisheri is widely distributed along the coastal plain of
southeastern Virginia and eastern North Carolina at least as far south
as Wilmington, North Carolina; that S. l. fisheri uses a wide variety
of habitat types; and that S. l. fisheri is not in danger of genetic
swamping by S. l. longirostris. However, the team agreed that the
reports should be sent out for independent peer review before further
action was taken. The Service sent the reports to independent peer
reviewers in June 1996. Reviewers that responded concurred with the
conclusions of the authors and were supportive of delisting, Based on
comments provided by recovery team members, the Service, and peer
reviewers, the original manuscripts were revised (Moncrief 1996,
Webster et al. 1996b).
Federal involvement with the Dismal Swamp southeastern shrew after
listing has included surveys for new locations and informal and formal
section 7 consultations for activities (involving a Federal action)
occurring in suitable habitat within the historical Dismal Swamp. No
jeopardy biological opinions for this species have been issued.
Processing of this proposed rule conforms with the Service's
Listing Priority Guidance for Fiscal Years 1998 and 1999, published on
May 8, 1998 (63 FR 25502). The guidance clarifies the order in which
the Service will process rulemakings giving highest priority (Tier 1)
to processing emergency rules to add species to the Lists of Endangered
and Threatened Wildlife and Plants (Lists); second priority (Tier 2) to
processing final rules to add species to the Lists, processing proposed
rules to add species to the Lists, processing administrative findings
on petitions (to add species to the Lists, delist species, or
reclassify listed species), and processing a limited number of proposed
or final rules to delist or reclassify species; and third priority
(Tier 3) to processing proposed or final rules to designate critical
habitat. Processing of this proposed rule is a Tier 2 action.
Summary of Factors Affecting the Species
Procedures found at section 4(a)(1) of the Endangered Species Act
and regulations (50 CFR part 424) promulgated to implement the listing
provisions of the Act were followed. Regulations at 50 CFR 424.11
require that certain factors be considered before a species can be
listed, reclassified, or delisted. These factors and their application
to the Dismal Swamp southeastern shrew (Sorex longirostris fisheri
Merriam) are as follows:
A. The Present or Threatened Destruction, Modification, or Curtailment
of its Habitat or Range
Extensive habitat alteration has occurred within the area
historically occupied by Dismal Swamp. At the beginning of the
twentieth century, the Dismal Swamp occupied 2,000 to 2,200 square
miles (sq mi) (5,200 to 5,700 square kilometers (sq km)). Currently,
less than 320 sq mi (830 sq km) of the historical Dismal Swamp remain,
189 sq mi (490 sq km) of which are protected within the Refuge and the
Great Dismal Swamp State Park in North Carolina. Remnants of the
historical Dismal Swamp outside Refuge and State Park boundaries and
land beyond the historical Dismal Swamp boundaries are disappearing due
to development associated with the rapid growth of the Hampton Roads
metropolitan area of
[[Page 56132]]
southeastern Virginia. Agricultural and silvicultural conversions
(especially in North Carolina) also contribute significantly to habitat
loss. Habitat loss was a primary reason for listing the Dismal Swamp
southeastern shrew, considered at the time to be endemic to the
historical Dismal Swamp. However, because the species is now known to
occur across a much larger area and in a wider variety of habitats (see
the ``Background'' section of this rule), the threat of habitat loss is
not as significant as was believed at the time of listing.
B. Overutilization for Commercial, Recreational, Scientific, or
Educational Purposes
At present, the only known method for studying or monitoring the
Dismal Swamp southeastern shrew involves lethal collection with pitfall
traps. Researchers have been permitted to take individuals of the
species to gain an understanding of its taxonomy, ecology, and
distribution. However, because the Dismal Swamp southeastern shrew has
a high reproductive potential and a rapid maturation rate, limited
collection of individuals is not considered detrimental to healthy
populations. Utilization for commercial, recreational, or educational
purposes is not known to occur.
C. Disease or Predation
Southeastern shrews are subject to some predation, most frequently
by owls, snakes, opossums, and domestic cats and dogs (French 1980,
Webster et al. 1985). The number of dead shrews found in woods and on
roads suggests that many predators reject the shrew, probably because
of the bad taste associated with their musk glands (French 1980). There
is no evidence that predation or disease is a significant threat to the
Dismal Swamp southeastern shrew.
D. The Inadequacy of Existing Regulatory Mechanisms
Wetland habitats for the Dismal Swamp southeastern shrew will
continue to receive protection indirectly under Section 404 of the
Clean Water Act which requires the Department of the Army, Corps of
Engineers to regulate certain activities affecting ``waters of the
United States'' including wetlands. However, delisting the Dismal Swamp
southeastern shrew will remove Federal prohibitions against take and
activities involving a Federal action which would jeopardize the
continued existence of the species. However, because of its wide
distribution and use of a wide variety of habitats, the removal of
these protections afforded by the Act will not pose a significant
threat to the Dismal Swamp southeastern shrew.
The Dismal Swamp southeastern shrew is listed as threatened by the
State of Virginia. Virginia's Endangered Species Act of 1972, as
amended (Code of Virginia Section 29.1-564-568) prohibits the taking,
transportation, processing, sale, or offer for sale of endangered and
threatened species except as permitted. The Virginia Department of Game
and Inland Fisheries provides general protection to wildlife through
State law Section 29.1-521, which prohibits their possession and
capture including the attempt to capture, take, kill, possess, offer
for sale, sell, offer for purchase, purchase, deliver for
transportation, transport, cause to be transported, receive, export,
import in any manner or in any quantity except as specifically
permitted.
The Dismal Swamp southeastern shrew is listed as threatened by the
State of North Carolina. The species is protected by North Carolina
general statute Article 25, section 113-337, which makes it unlawful to
take, possess, transport, sell, barter, trade, exchange, export, or
offer for sale, barter, trade, exchange, or export, or give away for
any purpose including advertising or other promotional purpose any
animal on a protected wild animal list, except as authorized according
to the regulations of the North Carolina Wildlife Resources Commission.
All States will have the option of retaining the Dismal Swamp
southeastern shrew on their various lists if it is removed from the
Federal List of Endangered and Threatened Wildlife. Both the States of
Virginia and North Carolina support the delisting. The State of North
Carolina plans to delist Dismal Swamp southeastern shrew if it is
delisted at the Federal level (H. LeGrand, North Carolina Natural
Heritage Program, pers. comm. 1997). However, because of its wide
distribution and use of a wide variety of habitats, the removal of
State protection will not constitute a significant threat to the
species.
E. Other Natural or Manmade Factors Affecting Its Continued Existence
One of the reasons for listing the Dismal Swamp southeastern shrew
was concern regarding the possible loss of genetic integrity through
interbreeding with the nominate subspecies. Gurshaw (1996) examined
allozyme variability in specimens of the southeastern shrew from North
Carolina and Virginia. She found an allele in the shrews from the
coastal plain that represents a genetic distinction from Sorex
longirostris longirostris and that appeared to follow the Fall Line.
The author stated, ``A cline for this allele may be shifted in the
direction of dispersal in proportion to the direction of gene flow
through barriers such as the Fall Line and population size. If the
populations containing * * * (this) * * * allele are small, they will
not have as many individuals dispersing * * * and gene flow may be
restricted (Endler, 1977). In this study, however, the opposite appears
to be happening. Populations with * * * (this allele)* * * are
widespread in eastern North Carolina and southeastern Virginia, with
gene flow carrying * * * (this) * * * allele above the Fall Line in
central North Carolina.'' She concluded that genetic swamping within
the Dismal Swamp region was not evident.
Webster et al. (1996a, 1996b) found that intergradation between
Sorex longirostris fisheri and S. l. longirostris is evident in
specimens from the inner coastal plain of Virginia and North Carolina.
The zone of intergradation is relatively narrow in Virginia and
relatively wide in North Carolina, commensurate with the relative size
of the inner coastal plain. Shrews from samples immediately to the east
and west of the present Dismal Swamp were slightly smaller than shrews
from the Dismal Swamp in cranial and external measurements. This trend
was noted by Padgett et al. (1987). However, when compared with
specimens from throughout the range of the species, these shrews are
referable to S. l. fisheri.
The following summarizes available information regarding potential
environmental contaminant threats to the Dismal Swamp southeastern
shrew throughout its range. In 1987 and 1989, the Service conducted a
preliminary study (Ryan et al. 1992) within the Refuge to determine if
contaminants were impacting fish and small mammals. All water (metal-
laden leachate and groundwater) draining the Suffolk City Landfill, at
the time a federally designated Superfund site, enters the Refuge. This
landfill received industrial and domestic wastes, including 30 tons of
organophosphate pesticides in the 1970s. Numerous automobile junkyards
border the Refuge to the north and drain into the Dismal Swamp and the
Refuge. Oil, grease, metals, polycyclic aromatic hydrocarbons (PAHs)
and alkanes (PAHs and alkanes are components of petroleum products) are
common constituents of junkyard and roadway runoff. Agricultural fields
to the north and west of the Refuge contribute surface runoff that may
contain residual herbicides, insecticides, and fungicides.
[[Page 56133]]
The Service's study (Ryan et al. 1992) included analyses for
contaminant residues in the short-tailed shrew (Blarina brevicauda).
Short-tailed shrews trapped near the East Ditch displayed elevated
levels of lead, mercury, and several organochlorine pesticides. The
lead levels for short-tailed shrews exceeded normal ranges and fell
within the range for lead toxicosis according to Ma (1996). Small
mammal lead toxicosis symptoms may include neurological dysfunction,
reproductive disorders (including stillbirths), liver and kidney
failure, etc. Apart from overt symptoms, asymptomatic effects may occur
at lower levels and have significant effects on animal behavior, yet be
difficult to evaluate and/or document. Ryan et al. (1992) found that
mercury levels for short-tailed shrews collected at East Ditch, Badger
Ditch, Railroad Ditch, and Pocosin Swamp were elevated in comparison to
levels for short-tailed shrews collected from the study reference
location and other sites within the Refuge. The mercury levels reported
for short-tailed shrews, although elevated when compared within study
area sites, were below those levels reported in the literature as
causing observed adverse effects. Organochlorine pesticide levels of
short-tailed shrews from the East Ditch were higher than those reported
from all other study sites. However, the levels were below those
documented in the literature for observed adverse effects. In summary,
there may be a contaminant concern for the Dismal Swamp southeastern
shrew near the East Ditch of the Refuge. However, no contaminant
analysis has been conducted in Dismal Swamp southeastern shrews.
Further monitoring has been recommended by the Service.
Small mammals tend to have limited ranges, and, therefore, elevated
levels of contaminants found in shrews from one location cannot be
interpreted as a condition for shrews throughout the Refuge or range.
Land uses such as agriculture, transportation, and urbanization with
increased impervious surfaces contribute measurable levels of
contaminants to the environment, and many persistent contaminants are
passed through the food web. However, the Service does not have any
information indicating that contaminants pose a significant threat to
the continued existence of the Dismal Swamp southeastern shrew.
In developing this proposed rule, the Service has assessed the best
available scientific and commercial information regarding the past,
present, and future threats to the Dismal Swamp southeastern shrew, as
well as information on its distribution, its habitat use, and the
security of its genetic integrity. Based on this evaluation, the Dismal
Swamp southeastern shrew no longer meets the definition of
``threatened'' under the Act, and the preferred action is to remove the
species from the List of Endangered and Threatened Wildlife, thereby
removing the protection afforded by the Act.
Regulations at 50 CFR 424.11(d) state that a species may be
delisted if (1) it becomes extinct, (2) it recovers, or (3) the
original data for classification were in error. The Service has
determined that the original data for classification of the Dismal
Swamp southeastern shrew as a threatened species were in error.
However, it is important to note that the original data for
classification constituted the best available scientific and commercial
information available at the time and were in error only in the sense
that they were incomplete. Because Sorex longirostris from the Dismal
Swamp were originally classified as S. l. fisheri based on
morphological measurements from a limited number of specimens, and
because specimens from areas bordering the Dismal Swamp did not have
similar morphological measurements, taxonomists logically concluded
that only the largest specimens were S. l. fisheri. It has been assumed
since the early 1900s that small-sized shrews were S. l. longirostris,
resulting in erroneous classification of shrews found outside, and
sometimes within, the historical Dismal Swamp boundaries. Therefore,
the perception of a restricted range for S. l. fisheri was not a
misinterpretation on the part of the Service, but a longstanding
scientific assumption. At the time of listing, no other interpretation
could be reasonably construed from the available data. The Service
concludes that the data supporting the original classification were
incomplete and that new data indicate removing S. l. fisheri from the
List of Endangered and Threatened Wildlife is warranted.
The listing of the Dismal Swamp southeastern shrew as a threatened
species was based on the best information available and was thus a
valid decision at the time; the data leading to a better understanding
of S. longirostris taxonomy were derived incrementally as a direct
result of the recovery program; and no preceding shrew research
anticipated the outcome of the final morphometric and genetic analyses.
The dual effort to increase the base of available information while
addressing the perceived threats to this subspecies was thus both
legally and scientifically justified up to the point when new
information yielded a significant change in the knowledge of the Dismal
Swamp southeastern shrew's status.
The Service, after conducting a review of the species' status,
determines that the species is not in danger of extinction throughout
all or a significant portion of its range, nor is it likely to become
so within the foreseeable future. Based on the best scientific and
commercial information available including information showing a wider
distribution than previously believed, utilization of a wider variety
of habitat types than previously believed, and genetic security, the
Service concludes that the Dismal Swamp southeastern shrew does not
warrant the protection of the Endangered Species Act of 1973, as
amended. The information leading to this conclusion was derived through
the recovery process, which included studies to verify the shrew's
taxonomic status and to conclusively determine its distribution. In
proposing delisting, the Service is conforming to the objectives stated
in the recovery plan. Our ability to propose this subspecies for
delisting is based on a very intentional strategy of conducting
comprehensive studies that built on the incremental and cumulative
insights of various experts. During this lengthy process, the
dedication of recovery team members and other knowledgeable parties was
invaluable in protecting the shrew when its status seemed much more
precarious, and in furthering our knowledge of it.
Effects of the Rule
This action, if enacted, will result in the removal of the Dismal
Swamp southeastern shrew from the List of Endangered and Threatened
Wildlife. Federal agencies would no longer be required to consult with
the Secretary of the Interior to insure that any action they authorize,
fund, or carry out will not likely jeopardize the continued existence
of the species. There is no designated critical habitat for this
species. Federal restrictions on taking would no longer apply. The 1988
amendments to the Act require that all species that have been delisted
due to recovery be monitored for at least 5 years following delisting.
Since the Dismal Swamp southeastern shrew is being proposed for
delisting because of new information indicating it has an expanded
distribution, is not under serious threat from habitat loss, and is
genetically secure, and not because it has been recovered, the Service
does not intend to monitor the species for 5 years following delisting.
Within the Refuge
[[Page 56134]]
and the Great Dismal Swamp State Park in North Carolina, management
will continue to focus on restoring the hydrological regime to as close
to historical conditions as possible given the necessity for firebreaks
and access roads. In addition, efforts are being made to restore or
maintain the habitat mosaic through forestry practices. It is the
opinion of the Service that sufficient habitat will remain over the
long-term to allow for the continued viability of this subspecies.
Public Comments Solicited
The Service intends that any final action resulting from this
proposal will be as accurate and as effective as possible. Therefore,
comments or suggestions from the public, other concerned governmental
agencies, the scientific community, industry, or any other interested
party concerning this proposed rule are hereby solicited. Comments
particularly are sought concerning:
(1) Biological, commercial trade (legal and illegal), or other
relevant data concerning any threat (or lack thereof) to the Dismal
Swamp southeastern shrew;
(2) The location of any additional populations or occurrences of
this species;
(3) Additional information concerning the range, distribution, and
population size of this species;
(4) Current or planned activities in the subject area and their
possible impacts on this species; and
(5) The number, origin, location and legal deposition of
individuals of this species in captivity and/or trade.
Promulgation of the final regulations on this species will take
into consideration the comments and any additional information received
by the Service, and such communications may lead to a final regulation
that differs from this proposal.
The Endangered Species Act provides for one or more public hearings
on this proposal, if requested. Requests must be received within 45
days of the date of publication of this proposal in the Federal
Register. Such requests must be made in writing and addressed to the
Field Supervisor (see ADDRESSES section).
Executive Order 12866 requires each agency to write regulations
that are easy to understand. We invite your comments on how to make
this rule easier to understand including answers to questions such as
the following: (1) Are the requirements in the rule clearly stated? (2)
Does the rule contain technical language or jargon that interferes with
its clarity? (3) Does the format of the rule (grouping and order of
sections, use of headings, paragraphing, etc.) aid or reduce its
clarity? (4) Would the rule be easier to understand if it were divided
into more (but shorter) sections? (A ``section'' appears in bold type
and is preceded by the symbol ``Sec. '' and a numbered heading; for
example, Sec. 17.11 Endangered and threatened wildlife.) (5) Is the
description of the rule in the ``Supplementary Information'' section of
the preamble helpful in understanding the rule? What else could we do
to make the rule easier to understand?
National Environmental Policy Act
The Fish and Wildlife Service has determined that Environmental
Assessments and Environmental Impact Statements, as defined under the
authority of the National Environmental Policy Act of 1969, need not be
prepared in connection with regulations adopted pursuant to Section
4(a) of the Endangered Species Act of 1973, as amended. A notice
outlining the Service's reasons for this determination was published in
the Federal Register on October 25, 1983 (48 FR 49244).
Required Determinations
This rule does not include any collections of information that
require approval by the Office of Management and Budget under 44 U.S.C.
3501 et seq.
References Cited
A complete list of all references cited herein is available upon
request from the U.S. Fish and Wildlife Service, Virginia Field Office
(see ADDRESSES section).
Author
The primary author of this document is Cynthia A. Schulz (see
ADDRESSES section).
List of Subjects in 50 CFR Part 17
Endangered and threatened species, Exports, Imports, Reporting and
recordkeeping requirements, Transportation.
Proposed Regulation Promulgation
Accordingly, the Service hereby proposes to amend part 17,
subchapter B of chapter I, title 50 Code of Federal Regulations, as set
forth below:
PART 17--[AMENDED]
1. The authority citation for part 17 continues to read as follows:
Authority: 16 U.S.C. 1361-1407; 16 U.S.C. 1531-1544; 16 U.S.C.
4201-4245; Pub. L. 99-625, 100 Stat. 3500; unless otherwise noted.
Sec. 17.11 [Amended]
2. Amend Sec. 17.11(h) by removing the entry for ``Shrew, Dismal
Swamp southeastern, Sorex longirostris fisheri'' under ``Mammals'' from
the List of Endangered and Threatened Wildlife.
Dated: October 6, 1998.
Jamie Rappaport Clark,
Director, U.S. Fish and Wildlife Service.
[FR Doc. 98-28189 Filed 10-20-98; 8:45 am]
BILLING CODE 4310-55-P
