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Endangered and Threatened Wildlife and Plants; 90-Day Finding on a Petition to List the New England Cottontail as Threatened or Endangered
Note: EPA no longer updates this information, but it may be useful as a reference or resource.
[Federal Register: June 30, 2004 (Volume 69, Number 125)]
[Proposed Rules]
[Page 39395-39400]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr30jn04-18]
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DEPARTMENT OF THE INTERIOR
Fish and Wildlife Service
50 CFR Part 17
Endangered and Threatened Wildlife and Plants; 90-Day Finding on
a Petition to List the New England Cottontail as Threatened or
Endangered
AGENCY: Fish and Wildlife Service, Interior.
ACTION: Notice of 90-day petition finding and initiation of status
review.
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SUMMARY: We, the U.S. Fish and Wildlife Service (Service), announce a
90-day finding on a petition to list the New England cottontail rabbit
(Sylvilagus transitionalis) under the Endangered Species Act of 1973,
as amended (Act). We find that the petition presents substantial
information indicating that the listing of the New England cottontail
may be warranted. Therefore, we are initiating a status review to
determine if listing the species is warranted. To ensure that the
review is comprehensive, we are soliciting information and data
regarding this species.
DATES: The administrative finding announced in this document was made
on June 2, 2004. To be considered in the 12-month finding for this
petition, comments and information should be submitted to us by August
30, 2004.
ADDRESSES: Data, information, comments, or questions concerning this
petition and our finding should be submitted to the Field Supervisor
(Attention: Endangered Species), New England Field Office, 70
Commercial Street, Suite 300, Concord, New Hampshire 03301. The
petition, administrative finding, supporting data, and comments will be
available for public inspection, by appointment, during normal business
hours at the above address.
FOR FURTHER INFORMATION CONTACT: Michael J. Amaral, Endangered Species
Specialist, at the New England Field Office (see ADDRESSES above), or
at 603-223-2541.
SUPPLEMENTARY INFORMATION:
Background
Section 4 (b)(3)(A) of the Endangered Species Act (Act) of 1973, as
amended (16 U.S.C. 1531 et seq.), requires that we make a finding on
whether a petition to list, delist, or reclassify a species, or to
revise a critical habitat designation, presents substantial scientific
or commercial information to demonstrate that the petitioned action may
be warranted. We are to base this finding on all information available
to us at the time the finding is made. To the maximum extent
practicable, we are to make this finding within 90 days of the receipt
of the petition, and to publish a notice of the finding promptly in the
Federal Register. Our regulations at 50 CFR 424.14(b) state that for
the purposes of petition findings, ``'substantial information'' is that
amount of information that would lead a reasonable person to believe
that the measure proposed in the petition may be warranted * * *.'' If
we find that substantial information was presented, we are required to
promptly commence a review of the status of the involved species, if
one has not already been initiated under our internal candidate
assessment process. After completing the status review, we will issue
an additional finding (the 12-month finding) determining whether
listing is, in fact, warranted.
Based on our regulations at 50 CFR 424.14(b)(2), in making a 90-day
finding as to whether a petition presents substantial scientific or
commercial information indicating that the petitioned action may be
warranted, we are to consider whether such petition--
(1) Clearly indicates the administrative measure recommended and
gives the scientific and any common names of the species involved;
(2) Contains detailed narrative justification for the recommended
measure, describing, based on available information, past and present
numbers and distribution of the species involved and any threats faced
by the species;
(3) Provides information regarding the status of the species over
all or a significant portion of its range; and
(4) Is accompanied by appropriate supporting documentation in the
form of bibliographic references, reprints of pertinent publications,
copies of reports or letters from authorities, and maps.
On August 30, 2000, we received a petition dated August 29, 2000,
requesting that we list the New England cottontail (Sylvilagus
transitionalis) as a threatened or endangered species, and that
critical habitat be designated ``within a reasonable period of time
following the listing.'' The petition, submitted by the Biodiversity
Legal Foundation, Conservation Action Project, Endangered Small Animals
Conservation Fund, and Defenders of Wildlife, was clearly identified as
a petition for a rule, and contained the names, signatures, and
addresses of the requesting parties. Included in the petition was
supporting information regarding the species' taxonomy and ecology,
historic and current distribution, present status, and potential causes
of decline. We acknowledged receipt of the petition in a letter to Mr.
D. C. Jasper Carlton, dated September 14, 2000. In this letter, we also
advised the petitioners that due to funding constraints in fiscal year
(FY) 2000, we would not be able to begin processing the petition in a
timely manner. Those constraints persisted into FY 2001.
On December 19, 2000, Defenders of Wildlife sent a Notice of Intent
to sue the Service for violating the Act by failing to make a timely
90-day finding on the petition to list the New England cottontail. On
May 14, 2002, we advised the Defenders of Wildlife that we would begin
action on the petition in FY 2002. This notice announces and summarizes
our 90-day finding for the petition to list the New England cottontail.
Biology and Distribution
Sometimes called the gray rabbit, brush rabbit, wood hare, or
coony, the New England cottontail is a medium-sized cottontail rabbit
that may reach 1,000 grams (g) (2.2 pounds (lbs)) in weight. Dorsal
portions of its body are buff to ocher in color, and the back is
overlain with distinct black hair (Chapman and Ceballos 1990). The ears
are short and rounded, and have a distinct black edge. There is a
distinct black spot between the ears.
A New England cottontail in the hand usually can be distinguished
from two sympatric lagomorphs (lagomorphs are a suborder of mammals
that includes rabbits, hares, and pikas), the eastern cottontail
(Sylvilagus floridanus) and the snowshoe hare (Lepus americanus), by
several features, including fur color, ear length, body mass, presence
of the black spot between the ears, absence of a white spot on the
forehead, and the
[[Page 39396]]
black line on the anterior edge of the ears (Litvaitis et al. 1991).
Pelage characteristics, however, are not 100 percent reliable in
distinguishing between the visually similar New England and eastern
cottontails (Chapman and Ceballos 1990), and the two species are
difficult to tell apart in the field. Cranial differences, however, are
a highly reliable means of distinguishing the two cottontail species
(Chapman and Morgan 1973).
The New England cottontail was formally described in 1894 (Bangs
1894 in Litvaitis and Johnson 2002). Until the early 1990s, the species
was considered to occur in a mosaic pattern from southeastern New
England, south along the Appalachian Mountains to Alabama (Hall 1981).
However, Ruedas et al. (1989) and others questioned the taxonomic
status of S. transitionalis because they found evidence of two distinct
chromosomal races within its geographic range. Chapman et al. (1992)
conducted a review of the systematics and biogeography of the species
and reported finding clear evidence for two morphometrically distinct
taxa within what had conventionally been regarded as a single species.
Accordingly, Chapman et al. (1992) defined a new species, the
Appalachian cottontail (S. obscurus), with a range from west of the
Hudson River, New York south along the Appalachian Mountains through
Pennsylvania, Maryland, West Virginia, Virginia, Tennessee, North
Carolina, South Carolina, Georgia, and Alabama. Chapman et al. (1992)
defined the New England cottontail (S. transitionalis) as that species
east of the Hudson River, New York, north through Vermont, Connecticut,
Rhode Island, Massachusetts, New Hampshire, and southern Maine.
In addition to the morphometric and genetic differences reported by
researchers, the two species also occupy somewhat different habitats.
The Appalachian cottontail is generally an inhabitant of ericaceous
vegetation zones (areas dominated by plants in the heath family)
associated with higher elevations and mountain balds, while the New
England cottontail occurs at lower elevations nearer the coastline, in
forested or disturbed habitats with a dense understory.
Not all biologists concur with the taxonomic separation proposed by
Chapman et al. (1992); see, for example, Litvaitis et al. (1997).
However, the change in taxonomy and nomenclature proposed by Chapman is
included in the Smithsonian Institution's book on North American
mammals (Chapman in Wilson and Ruff, eds., 1999). Jones et al. (1997),
in the revised checklist of North American mammals, also recognizes
both species as valid. The Service currently accepts the taxonomic
separation of S. transitionalis and S. obscurus.
Pursuant to the definitions in section 3 of the Act, ``the term
species includes any subspecies of fish or wildlife or plants, and any
distinct population segment of any species of vertebrate fish or
wildlife which interbreeds when mature.'' In order for a species to be
considered as a listable entity under the Act, it must meet the above
definition. The Service agrees with the petitioners that the New
England cottontail qualifies as a listable entity under the Act based
on the definition of species. We base this conclusion on two arguments.
First, we believe there is general acceptance of the S. transitionalis
/ S. obscurus taxonomy put forth by Chapman et al. (1992) as noted
above. Second, we believe that the New England cottontail within its
range in the Northeast (east of the Hudson River, New York) would
warrant listing consideration as a distinct vertebrate population
segment in the event that the taxonomy of these species is further
revised. Accordingly, and consistent with the species as described in
the petition, in this finding we are considering only the New England
cottontail (S. transitionalis), as defined and with the range as
described by Chapman et al. (1992). Consistent with Chapman et al.
(1992) and other references (Chapman and Ceballos 1990, Hall 1981), no
subspecies of the New England cottontail are recognized.
The New England cottontail is the only endemic cottontail in New
England (Probert and Litvaitis 1996). Because the New England
cottontail was not formally described until 1894 (Bangs 1894), there
are few comprehensive reports on the historic range of the species
(Litvaitis and Johnson 2002). However, it is believed that during early
European settlement, New England cottontails occurred in a more or less
continuous distribution from eastern New York (including Long Island)
through Connecticut, statewide in Massachusetts (Cardoza in litt.
1999), Rhode Island, southern Vermont at least to Rutland, New
Hampshire south of the White Mountains (Jackson 1922 in Jackson 1973),
and four counties in southern Maine (Couse and Allen 1877 in Litvaitis
and Johnson 2002).
Presently, the range of the New England cottontail appears to be
limited to relatively small patches of suitable habitat from eastern
New York, to several counties in Connecticut, western and possibly
northern Rhode Island, only a few locations in eastern Massachusetts
and in the Berkshire Mountains, several southern counties in New
Hampshire, and two southern coastal counties in Maine (Litvaitis and
Johnson 2002). The species has not been reported from Vermont since
1990 and may be extirpated there (Litvaitis 1993a; Litvaitis et al.
2002). Litvaitis and Johnson (2002) report that, since 1960, the region
occupied by the New England cottontail has declined by approximately 75
percent.
The eastern cottontail has been introduced into much of the range
of the New England cottontail. The historical range of the eastern
cottontail extended northeast only as far as the lower Hudson Valley,
and possibly extreme western Connecticut (Goodwin 1935 in Chapman and
Stauffer 1981). Large-scale introductions of eastern cottontails to
Connecticut (Dalke 1942, in Chapman and Stauffer 1981), Rhode Island
(Johnston 1972), Massachusetts (Nelson 1909, in Johnston 1972) and
possibly Vermont (C. M. Kilpatrick, in litt. 2002) have firmly
established the eastern cottontail in all of New England, except Maine.
Introductions usually have been conducted by States and private hunting
clubs. The eastern cottontail is both larger (1,300 g (2.9 lb)) and
more fecund than the New England cottontail.
Fay and Chandler (1955) documented the extension of the range of
introduced eastern cottontails in Massachusetts, and recorded that S.
floridanus had replaced the native New England cottontail in many
places. Linkkila (1971) reported the disappearance of S. transitionalis
throughout much of the northeastern United States. Johnston (1972)
described the replacement over a 40 to 50 year period of S.
transitionalis by S. floridanus as the predominant cottontail in much
of southern New England.
Despite the widespread introductions of eastern cottontails into
the range of the New England cottontail, the two species are not
hybridizing. Wilson (1981) conducted a genetic study of the two species
in five of the New England States and found that the New England
cottontail has maintained its genetic identity in the face of eastern
cottontail range expansion.
The New England cottontail is considered an early successional
forest species, where disturbance occurring as a result of timber
harvest, hurricanes and other wind storms, or beaver activity maintains
areas of suitable habitat. Historically, fires set by Native Americans,
a practice continued by early European colonists, also set back forest
succession and maintained areas of suitable habitat (Bromley 1935;
Cronon 1983). Suitable habitat for the
[[Page 39397]]
species can be found in both forest and shrub lands, provided there is
dense understory growth where both food and cover are found in close
proximity. New England cottontail habitats include native shrublands,
beaver flowages, old fields, and early successional forests (Barbour
and Litvaitis 1993). In southern New England, however, this cottontail
may also occur in more stable forests where laurel (Kalmia sp.)
provides a dense understory. Like other cottontails, the New England
cottontail is an herbivore and feeds on a wide variety of woody and
herbaceous plants.
There is considerable overlap between habitats used by eastern and
New England cottontails. In general, however, eastern cottontails are
associated with plants indicative of open land such as old fields and
meadows, whereas New England cottontails are associated with forest
plant species (Eabry 1968).
Status Concerns
The status of the New England cottontail has been of concern to
biologists and natural resource agencies for nearly five decades.
Reductions in the range of the New England cottontail were first
reported by Fay and Chandler (1955) and subsequently by Linkkila (1971)
and Johnston (1972). In 1979, Chapman and Stauffer suggested to the
International Union for the Conservation of Nature (IUCN) Lagomorph
Specialist Group that the species be listed in the category ``Special
Concern'' (Chapman and Stauffer 1981). In 1989, we placed the New
England cottontail in category 2 of the Animal Notice of Review (54 FR
553). We no longer maintain a list of category 2 candidate species, but
at the time, category 2 was defined as including species for which we
had some information indicating that the taxa may be under threat, but
not enough information was available to determine if they warranted
Federal listing and the preparation of a proposed rule.
On the basis of the research and other information noted above,
concern for the status of the New England cottontail was well
documented even prior to the revision of the taxon by Chapman et al.
(1992). The separation of the taxon into two species with reduced and
allopatric (separate) ranges resulted in increased concern for the New
England cottontail, which was recognized as being restricted to east of
the Hudson River, New York, and New England. In 1999, a committee
composed of 13 State endangered species and wildlife diversity program
coordinators included the New England cottontail among 26 declining
species most in need of conservation attention in the northeast region
(Therres 1999). This committee described the New England cottontail as
warranting ``federal endangered or threatened species listing
consideration, including prelisting status reviews.''
Conservation Status
Under section 4(a) of the Act, we may list a species on the basis
of any of five factors, as follows: ``(A) the present or threatened
destruction, modification, or curtailment of its habitat or range; (B)
overutilization for commercial, recreational, scientific, or
educational purposes; (C) disease or predation; (D) the inadequacy of
existing regulatory mechanisms; (E) other natural or manmade factors
affecting its continued existence.'' The petitioners contend that four
of the five factors (A, B, D, and E) are applicable to the New England
cottontail (see below). A brief discussion of how each of the five
listing factors applies to the New England cottontail follows.
In regard to factor A, the petitioners cite loss of habitat to
urban and suburban development as a major threat to the New England
cottontail. Further, the petitioners note that this species requires
thicket habitat frequently associated with early seral stages of forest
regeneration after a disturbance such as timber harvest, fire, or
beaver activity. They note that an increasingly urbanized landscape,
with many small, partially-forested residential parcels is not
conducive to timber harvesting, fire, or other disturbance regimes that
would maintain and/or regenerate habitat for the species.
Information currently available indicates that loss of habitat to
these and other causes appears to be a significant threat to the status
of this species. Litvaitis (1993b) considered habitat succession to be
the most important cause of habitat loss for this species. As
agricultural land in the Northeast was abandoned after the Civil War,
forest succession led to a period where habitat conditions were highly
favorable for early successional or thicket-dependent species such as
the New England cottontail. However, as forests matured and forest
canopy closed, the habitats entered a mid-successional stage and were
no longer suitable for these early successional species (Brooks and
Birch 1988). Further, Litvaitis et al. (1999) reported that remaining
shrub-dominated and early successional habitats in the Northeast
continue to decline in both coverage and suitability. U.S. Forest
Service inventories reveal that in New Hampshire and New York, the
extent of forest in the seedling/sapling stage (thickets favorable to
the New England cottontail) has declined by about 50 percent in the
past three decades (Askins 1998; Litvaitis et al. 1999). In Maine,
young forest stands in the two southern counties that still support
populations of the New England cottontail declined even more sharply,
from about 38 percent in 1971 to 11 percent in 1995 (Litvaitis et al.
2002).
In addition to habitat succession, development has also contributed
to direct and more permanent loss and fragmentation of habitat for the
species. The three southern New England states, Connecticut (>700
inhabitants per square mile), Rhode Island (>1,000 inhabitants per
square mile), and Massachusetts (>800 inhabitants per square mile),
which comprise the center of the New England cottontail's range, are
among the most densely populated areas in the United States (U.S.
Census Bureau 2000). Early successional habitats that once supported
New England cottontails have been converted to a variety of uses which
make them unsuitable for the species. Among shrub-dominated plant
communities, which sometimes support New England cottontail
populations, scrub oak and pitch pine barrens have been heavily
degraded by development (Patterson 2002). These areas are rapidly being
lost to uses such as airport development, roadways, sand and gravel
mining, industrial parks, residential development, and retail
development. Litvaitis et al. (1999) conclude that shrub-dominated and
early successional habitats may be the most altered and among the most
rapidly declining communities in the Northeast.
The fragmentation of remaining suitable habitats into smaller
patches separated by roads, residential, and other development can have
profound effects on the occupancy and persistence of New England
cottontail populations in relatively small patches. Barbour and
Litvaitis (1993) found that New England cottontails occupying small
patches of habitat (less than or equal to 2.5 hectares (ha) or about 6
acres) were predominantly males, had lower body mass, consumed lower
quality forage, and had to feed farther from protective cover than
rabbits in larger patches (greater than or equal to 5 ha or slightly
more than 12 acres). This study also demonstrated that New England
cottontails in the smaller patches had only half the survival rate of
those in the larger patches due to increased mortality from predation.
Barbour and Litvaitis (1993) concluded that local populations of New
England cottontails may be vulnerable to
[[Page 39398]]
extinction if large patches of habitat are not maintained.
Although there are no reliable estimates for historic or current
population numbers of New England cottontails, the reduction in the
amount of suitable habitat and the range of the species, as well as the
effects of competition and predation, are believed to have resulted in
a concomitant reduction in numbers.
In regard to factor B, the petitioners contend that while anecdotal
evidence implies that hunting pressure on the New England cottontail
(and rabbits in general) is not severe, ``any hunting, in a population
reduced to remnants as the NE cottontail is, is too much.''
Our review of information for this 90-day finding indicates there
is presently little hunting pressure on New England cottontails. All of
the State wildlife agencies within the range of the New England
cottontail regard it as a small game animal and allow hunting with
specific season and bag restrictions. Most States report fewer rabbit
and other small game hunters today than in earlier decades (U.S. DOI
and U.S. DOC 1985, 1991, 1996, 2001), and the New England cottontail is
not the rabbit species preferred by most small game hunters because of
its smaller size and behavior. New England cottontails forage within or
close to dense cover (Smith and Litvaitis 2000), and typically hold in
safe areas when disturbed. They are therefore not as easily run by
hounds and taken by hunters as eastern cottontails or snowshoe hares.
Research shows that New England cottontails are more vulnerable to
mortality from predation in smaller patches of habitat than in larger
ones (Barbour and Litvaitis 1993). This may hold true for hunting
mortality as well, because rabbits on small patches must venture
farther from shelter to feed and have less escape cover in which to
hide, but this has not been demonstrated.
The petitioners also assert that rabbits may still be regarded as
pests and killed indiscriminately by farmers, but provided no objective
information to support that assertion. In our review of available
information, we did not find evidence either to support or refute this
claim. However, because of differences in habitat preference of the two
cottontail species, most farmers and homeowners are more likely to
encounter eastern cottontails, which occur in the more open habitats of
farms and residential lawns, than New England cottontails. Whether
either species is killed indiscriminately by farmers, however, is an
assertion that lacks supporting information in the petition. Thus, on
the basis of available information, current human hunting pressure does
not appear to be a significant mortality factor for the New England
cottontail.
The petitioners speculate that hunting pressure on the New England
cottontail earlier in the century (e.g., 1930s) led to declining
numbers of rabbits, and in response to reduced hunting opportunity,
States and hunting clubs then introduced large numbers of eastern
cottontails, with ``disastrous'' results. The Service agrees that the
introduction and establishment of eastern cottontail populations in the
Northeast for the purpose of providing small game hunting opportunities
has been deleterious to the New England cottontail. However, available
evidence suggests that habitat loss, through forest maturation and
other causes (Jackson 1973; Brooks and Birch 1988; Litvaitis et al.
1999), rather than hunting pressure, was the primary reason for the
decline of New England cottontail populations in the mid-20th century.
With regard to disease (factor C), the petitioners cited one
reference that suggested disease could be a factor in the decline of
the New England cottontail, but stated that no specifics were provided.
In our review of available information, we found little evidence to
suggest that disease is a limiting factor for this species. Cottontail
rabbits are known to contract a number of different diseases, such as
tularemia, and are afflicted with both ecto-parasites such as ticks,
mites and fleas, and endo-parasites such as tapeworms, and nematodes
(Eabry 1968). Chapman and Ceballos (1990) do not identify disease as an
important factor in the dynamics of cottontail populations. Rather,
they state that habitat is key to cottontail abundance and that
populations are regulated through other causes of mortality and
dispersal. Further, they note that escape cover is an essential habitat
requirement, suggesting that mortality from predation is an important
population regulation mechanism.
With regard to predation, the petitioners discussed its importance
as a mortality factor in the section, ``life history and ecology of the
New England cottontail,'' but did not refer to predation as a threat to
the species in their review of the five listing factors (Carlton et al.
2000). Available information indicates that predation is likely a
significant cause of mortality for New England cottontails and that
both mammalian and avian predators are important. Because female New
England cottontails are capable of producing 24 young annually (Chapman
and Ceballos 1990), the species has the potential to be abundant were
it not for mortality and other factors affecting population growth.
Litvaitis et al. (1984) noted that New England cottontails were a major
prey of bobcats (Felis rufus) in New Hampshire during the 1950s.
Presently, coyotes (Canis latrans) and red foxes (Vulpes vulpes) are
believed to be the major predators of the New England cottontail in New
Hampshire (Barbour and Litvaitis 1993; Brown and Litvaitis 1995). Among
avian predators known or suspected to take cottontails are several
species of owls (Smith 1997, in Smith and Litvaitis 1999) and red-
tailed hawks (Buteo jamaicensus) (Bent 1961). Lastly, anecdotal
evidence and at least one study (Walter et al. 2001) indicate that
cottontails are also killed by domestic dogs and cats.
Available evidence suggests that habitat fragmentation has
exacerbated predation rates and reduced New England cottontail survival
in several ways. Populations of generalist carnivores have increased
with forest fragmentation (Oehler and Litvaitis 1996), and supplemental
food resources associated with human dwellings (e.g., trash, bird
feeders, fruiting shrubs) may lead to ``spillover'' predation on
cottontails (Oksanen et al. 1992, in Brown and Litvaitis 1995).
Studies have shown that, as landscapes become fragmented, New
England cottontails become increasingly vulnerable to predation,
because habitat quantity and quality are reduced (less forage and
escape cover) (Smith and Litvaitis 2000). A study by Villafuerte et al.
(1997) demonstrated that the abundance of food and the risk of
predation are very influential in determining the persistence of small-
and medium-sized vertebrates such as the New England cottontail. As
food in the most secure areas is depleted, rabbits are forced to
utilize lower quality forage or feed farther from cover where the risk
of predation is greater. This study found that rabbits on small patches
were ``on the lowest nutritional plane'' and as a result, were killed
at twice the rate (and were killed sooner) than rabbits on larger
habitat patches. Villafuerte et al. (1997) concluded that forage
limitations imposed by habitat fragmentation affect the viability of
local populations of New England cottontails by influencing their
vulnerability to predation. Rabbits on larger patches were less
vulnerable; therefore, they concluded that large patches of habitat are
essential for sustaining populations of this species in a human-altered
landscape. Smith and Litvaitis (2000) report that because eastern
cottontails appear to have the ability to forage farther from cover and
detect predators
[[Page 39399]]
sooner than New England cottontails, eastern cottontails will likely
persist while populations of New England cottontails will continue to
decline.
In regard to factor D, the petitioners cite the inability of State
wildlife agencies to adequately monitor the status of the New England
cottontail within their respective jurisdictions as a threat to the
species. We note that the lack of monitoring is not a threat to a
species per se but agree that adequate monitoring is important in order
to promptly detect and respond to a decline in a species' status.
Conducting research on the status of this species is relatively
difficult and expensive because New England cottontails are labor
intensive to capture, and identifying them in the field is seldom
possible due to their general similarity to the eastern cottontail.
Also, because the habitat conditions that support New England
cottontail populations change over time with plant succession (e.g.,
forest maturation), status surveys (even presence/absence surveys) need
to be repeated periodically. Many States, such as Massachusetts, Rhode
Island, and Connecticut, have attempted to monitor the status of the
New England cottontail through voluntary hunter and public submittal of
specimens. While these data fall short of providing a comprehensive
review of the status of the species in a particular state, they are
nonetheless useful in demonstrating abundance relative to eastern
cottontails, locations of occupied habitats, and trends in frequency of
occurrence over time.
All seven State wildlife agencies within the northeastern area have
the authority to control the hunting of New England cottontails through
the setting of hunting and trapping seasons and bag limits. However,
most northeastern States cannot presently restrict hunting of New
England cottontails without also reducing hunting opportunities for
eastern cottontails and, to a lesser extent, snowshoe hares. This is
because these species are visually similar in the field and they co-
occur on the landscape, sometimes within the same or adjacent habitat
patches. In Maine, where the only cottontail is the New England
cottontail, the state has limited hunters to one cottontail per day and
two in possession (Maine Hunting and Trapping Laws and Rules 2003).
While States have legal authority to address the mortality of New
England cottontails from hunting and trapping, there are only limited
regulatory mechanisms available to address the loss of habitat. New
England cottontails occur on sites with dense understory vegetation,
including native shrublands, beaver flowages, old fields, and early
successional forests (Barbour and Litvaitis 1993). In Connecticut,
Walter et al. (2001) reported that most current New England cottontail
collection records are associated with sites that contain or are
adjacent to riparian vegetation, such as borders of lakes, swamps, and
rivers. However, the New England cottontail is primarily an upland,
terrestrial species that occurs along the margins of these wetland
types. This suggests that Federal and State laws that provide
protection to shorelands and wetlands may offer some protection to a
small portion of New England cottontail habitat (see also the
discussion of factor A regarding habitat loss).
Several areas that have persistent populations of New England
cottontails are on lands protected by Federal or State ownership and
some are being managed for early successional species. However, in our
review of information available for this 90-day finding, we were unable
to determine the number and location of large patches of occupied New
England cottontail habitat which occur on State and Federal
conservation lands. Quantifying this information will be an important
component of the status review.
In regard to factor E, the petitioners address the adverse effects
of eastern cottontail introductions. On the basis of available
information, we would agree that the introduction and spread of eastern
cottontails has been a factor in reducing the occurrence of the New
England cottontail within its historic range. Tens of thousands of
individuals of four or five different subspecies of S. floridanus were
introduced to the Northeast, beginning on Nantucket Island,
Massachusetts, in 1899 (Johnston 1972), and continuing elsewhere in
Massachusetts, Connecticut, New Hampshire, and Rhode Island until the
1960s. In States where researchers and State wildlife agencies reported
the New England cottontail had been the predominant or the only
cottontail encountered during the early- to mid-1900s, by the latter
half of the century the eastern cottontail had become by far the most
common rabbit (Johnston 1972; Tracy 1995; Cardoza, in litt. 1999).
Maine, where the eastern cottontail is not known to occur, is the only
exception to this pattern. In summary, Johnston (1972) reported that
this occupation of new areas by S. floridanus seemed to be at the
expense of S. transitionalis.
Although the precise mechanism explaining how eastern cottontails
displace New England cottontails is not known, it is well established
that as the range of the eastern cottontail expanded, that of the
indigenous New England cottontail declined. Probert and Litvaitis
(1996) found that eastern cottontails, though larger, were not
physically dominant over New England cottontails. Rather, they believe
that eastern cottontails are able to exploit a broader set of
ecological conditions and, through more efficient or rapid use of
available resources, they have been able to replace New England
cottontails in many habitats. Eastern cottontails appear capable of
occupying a wider range of available habitat types and can occupy
disturbance patches earlier than New England cottontails. Once
established, the highly fecund eastern cottontails are not readily
displaced by the New England cottontails.
Our review of available information indicates there are other
natural and man-made factors that may be affecting the status of the
New England cottontail. Winter severity, measured by persistence of
snow cover, is believed to affect New England cottontail survival.
Villafuerte et al. (1997) found that snow cover reduces the
availability of high-quality foods, and likely results in rabbits
becoming weakened nutritionally. In a weakened state, rabbits are more
vulnerable to predation. Brown and Litvaitis (1995) found that during
winters with prolonged snow cover, a greater proportion of the
cottontails in their study were killed by predators. Litvaitis and
Johnston (2002) speculate that snow cover may explain the largely
coastal distribution of this species in the Northeast (generally less
snow falls and persists in coastal versus interior areas) and may be an
important factor defining the northern limit of its range. The
preceding studies suggest that during winters with heavy snowfall, New
England cottontail numbers will be reduced, and the combined effects of
snowfall and habitat fragmentation will affect the persistence of
populations in smaller patches.
State wildlife agencies report that road kills are an important
source for obtaining specimens of rabbits, including the New England
cottontail. Road-killed rabbits were second only to hunting mortality
as a source for obtaining cottontail specimens in an ongoing
distributional study of eastern and New England cottontails in
Connecticut (Walter et al. 2001). The degree to which New England
cottontail populations are affected by vehicular mortality is unknown,
but roads may be an important limitation for dispersing individuals.
[[Page 39400]]
Litvaitis and Johnson (2002) note that cottontails are often found
in habitats that have invasive plant species, such as honeysuckle
(Lonicera spp.). Whether exotic plant species have a positive or
negative effect on the New England cottontail is presently unknown.
Finding
We have reviewed the petition, the literature cited in the
petition, and other literature and information available in our files.
On the basis of our review, we find that the petition presents
substantial information indicating that listing the New England
cottontail may be warranted. The main threat to the species appears to
be loss of habitat through forest succession, fragmentation, and
conversion to other uses. This loss of habitat has contributed to a
reduction in the range of the species and a reduction in numbers.
Ongoing competition with eastern cottontails that have been introduced
into areas that are outside their native range also appears to be
having a negative impact on the New England cottontail.
We have reviewed the available information to determine if the
existing and foreseeable threats pose an emergency. We have determined
that an emergency listing is not warranted at this time, because many
scattered occurrences of the New England cottontail are still known to
occur across its range, and some are on protected lands. However, if at
any time we determine that emergency listing of the New England
cottontail is warranted, we will seek to initiate an emergency listing.
The petitioners also requested that critical habitat be designated
for this subspecies. We always consider the need for critical habitat
designation when listing species. If we determine in our 12-month
finding that listing the New England cottontail is warranted, we will
address the designation of critical habitat in the subsequent proposed
rule or as funding allows.
Public Information Solicited
When we make a finding that substantial information exists to
indicate that listing a species may be warranted, we are required to
promptly commence a review of the status of the species. To ensure that
the status review is complete and based on the best available
scientific and commercial information, we are soliciting information on
the New England cottontail. We request any additional information,
comments, and suggestions from the public, other concerned governmental
agencies, Native American Tribes, the scientific community, industry,
or any other interested parties concerning the status of the New
England cottontail. We are seeking information regarding historic and
current status and distribution, the species' biology and ecology,
ongoing conservation measures for the species and its habitat, and
threats to the species and its habitat.
If you wish to comment or provide information, you may submit your
comments and materials concerning this finding to the Field Supervisor
(see ADDRESSES section). Our practice is to make comments and materials
provided, including names and home addresses of respondents, available
for public review during regular business hours. Respondents may
request that we withhold a respondent's identity, to the extent
allowable by law. If you wish us to withhold your name or address, you
must state this request prominently at the beginning of your
submission. However, we will not consider anonymous comments. To the
extent consistent with applicable law, we will make all submissions
from organizations or businesses, and from individuals identifying
themselves as representatives or officials of organizations or
businesses, available for public inspection in their entirety. Comments
and materials received will be available for public inspection, by
appointment, during normal business hours at the above address.
References Cited
A complete list of all references cited herein is available upon
request from the Field Supervisor (see ADDRESSES section).
Author
The primary author of this document is Michael J. Amaral, New
England Field Office (see ADDRESSES section).
Authority
The authority for this action is the Endangered Species Act of
1973, as amended (16 U.S.C. 1531 et seq.).
Dated: June 2, 2004.
Marshall Jones,
Acting Director, U.S. Fish and Wildlife Service.
[FR Doc. 04-14610 Filed 6-29-04; 8:45 am]
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