Endangered and Threatened Wildlife and Plants; Proposed Rule To Delist the Dismal Swamp Southeastern Shrew (Sorex longirostris fisheri)

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]

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