BIOLOGICAL DATA AND HABITAT REQUIREMENTS
WILDLIFE SPECIES: Sylvilagus floridanus | Eastern Cottontail 



TIMING OF MAJOR LIFE HISTORY EVENTS : 
Diurnal Activity:  Eastern cottontails are crepuscular to nocturnal
feeders; although they usually spend most of the daylight hours resting
in shallow depressions under vegetative cover or other shelter; they
can be seen at any time of day [17,48].  Eastern cottontails are most
active when visibility is limited, such as rainy or foggy nights [27].
Eastern cottontails usually move only short distances, and they may
remain sitting very still for up to 15 minutes at a time [48].

Eastern cottontails are active year-round [48].

Breeding Season:  The onset of breeding varies between populations and
within populations from year to year.  The eastern cottontail breeding
season begins later with higher latitudes and elevations.  Temperature
rather than diet has been suggested as a primary factor controlling
onset of breeding; many studies correlate severe weather with delays in
the onset of breeding [10].  In New England breeding occurs from March
to September [17].  In New York the breeding season occurs from February
to September, in Connecticut from mid-March to mid-September.  In
Alabama the breeding season begins in January.  In Georgia the breeding
season lasts 9 months and in Texas breeding occurs year-round [10,48].
Populations in western Oregon breed from late January to early September
[10].  Mating is promiscuous [27].

Gestation and Development of Young:  The nest is a slanting hole dug in
soft soil and lined with vegetation and fur.  The average measurements
are: length 7.09 inches (18.03 cm), width 4.9 inches (12.57 cm), and
depth 4.71 inches (11.94 cm) [9].  The average period of gestation is
28 days, ranging from 25 to 35 days [48].  Eastern cottontail young are
born with a very fine coat of hair and are blind.  Their eyes begin to
open by 4 to 7 days.  Young begin to move out of the nest for short
trips by 12 to 16 days and are completely weaned and independent by 4
to 5 weeks [9,48,63].  Litters disperse at about 7 weeks [17].  Females
do not stay in the nest with the young but return to the opening of the
nest to nurse, usually twice a day [48,63].

Reproductive Potential:  Reproductive maturity occurs at about 2 to 3
months of age.  A majority of females first breed the spring following
birth [17]; but 10 to 36 percent of females breed as juveniles (i.e.,
summer of the year they were born) [52].  A typical litter in New
England is four or five young, ranging from three to eight [17].  In
Maryland the average litter size is 5.01 young, and ranges from 1 to 12.
In the South female eastern cottontails have more litters per year (up
to 7) but fewer young per litter [10,48].  In New England female eastern
cottontails have three or four litters per year [17].  The annual
productivity of females may be as high as 35 young [48].  Mammalian life
tables were compiled by Millar and Zammuto [45] and include eastern
cottontail data.  Wainright [63] reviewed the literature on eastern
cottontail reproduction.

Mortality/Survivorship:  In Kansas the largest cause of mortality of
radiotracked eastern cottontails was predation (43%), followed by
research mortalities (19%), and tularemia (18%) [3].  A major cause of
eastern cottontail mortality is collision with automobiles.  In Missouri
it was estimated that 10 eastern cottontails are killed annually per
mile of road.  The peak period of highway mortality is in spring (March
through May); roadside vegetation greens up before adjacent fields and
is highly attractive to eastern cottontails [52].

Annual adult survival is estimated at 20 percent.  Average longevity is
15 months in the wild; the longest lived wild individual on record was 5
years old.  Captive eastern cottontails have lived to at least 9 years
of age [48].

Diseases and Pests:  Eastern cottontails are hosts to fleas, ticks, lice,
cestodes, nematodes, trematodes, gray flesh fly larvae, botfly larvae,
tularemia, shopes fibroma, torticollis, and streptothricosis cutaneous
[27].  Further summary of diseases and pests is available [9].


PREFERRED HABITAT : 
Optimal eastern cottontail habitat includes open grassy areas,
clearings, and old fields supporting abundant green grasses and herbs,
with shrubs in the area or edges for cover [34].  The essential
components of eastern cottontail habitat are an abundance of
well-distributed escape cover (dense shrubs) interspersed with more open
foraging areas such as grasslands and pastures [1].  Habitat parameters
important for eastern cottontails in ponderosa pine, mixed species, and
pinyon (Pinus spp.)-juniper (Juniperus spp.) woodlands include woody
debris, herbaceous and shrubby understories, and patchiness [50].
Typically eastern cottontails occupy habitats in and around farms
including fields, pastures, open woods, thickets associated with
fencerows, wooded thickets, forest edges, and suburban areas with
adequate food and cover.  They are also found in swamps and marshes and
usually avoid dense woods [17,27].  They are seldom found in deep woods
[27].

In Maryland eastern cottontails use forest edges and strip vegetation;
rose (usually multiflora rose [Rosa multiflora]) hedgerows are most
heavily used [46].  In Ohio preferred habitats include patches of
briars, vine entanglements, brush piles, and small conifers [7].

In Michigan abandoned farmlands in various stages of succession were
assessed for eastern cottontail habitat.  Eastern cottontails were
present in all stages, but were most abundant from the fourth to the
sixth years after the last crop.  Most use occurred in grass/perennials
and mixed herbaceous perennials. Hayfields were preferred as nesting
sites.  Eastern cottontail numbers decreased through succession as
tolerant trees and canopy cover increased and shrubby ground cover
decreased [4].

In fragmented farmland habitats in southern Minnesota eastern cottontail
use is associated with dense woody vegetation and artificial cover
(brush piles), particularly in shelterbelts, strip vegetation
(uncultivated areas between fields), fencerows, and roadsides [58].

In western South Dakota eastern cottontails are associated with
black-tailed prairie dog (Cynomys ludovicianus) colonies due to the
presence of higher vegetative diversity around black-tailed prairie dog
colonies than in the surrounding prairie [53].

In Colorado cottontails, including eastern cottontail, were present in
greater numbers in ungrazed bottomlands than on grazed areas.  Within
the grazed areas eastern cottontails were present only where shrubs had
been moderately (instead of heavily) browsed [14].

In the Southeast eastern cottontails were most abundant in cultivated
areas, broomsedge (Andropogon virginicus) fields, and pine-hardwoods [44].

Home Range:  The eastern cottontail home range is roughly circular in
uniform habitats.  Eastern cottontails typically inhabit one home range
throughout their lifetime, but home range shifts in response to
vegetation changes and weather are common [1].  In New England eastern
cottontail home ranges average 1.4 acres (0.57 ha) for adult males and
1.2 acres (0.48 ha) for adult females [43] but vary in size from 0.5
acre to 40 acres (0.2-16.2 ha), depending on season, habitat quality,
and individual [17].  The largest ranges are occupied by adult males
during the breeding season.  In southwestern Wisconsin adult male home
ranges averaged 6.9 acres (2.8 ha) in spring, increased to 10 acres (4.0
ha) in early summer, and decreased to 3.7 acres (1.5 ha) by late summer
[61].  Daily activity is usually restricted to 10 to 20 percent of the
overall home range [1].

In southeastern Wisconsin home ranges of males overlapped by up to 50
percent, but female home ranges did not overlap by more than 25 percent
and actual defense of range by females occurred only in the immediate
area of the nest.  Males fight each other to establish dominance
hierarchy and mating priority [61].

Population Density:  Local concentrations of up to eight eastern
cottontails per acre (20/ha) have been recorded, but densities are
usually lower [9].  In Kansas peak population density was 2.59 rabbits
per acre (6.4/ha) [3].  Density is regulated by mortality and dispersal
[9,25].


COVER REQUIREMENTS : 
Eastern cottontails forage in open areas and use brush piles, stone
walls with shrubs around them, herbaceous and shrubby plants, and
burrows or dens for escape cover, shelter, and resting cover [17].
Woody cover is extremely important for the survival and abundance of
eastern cottontails [1].  Eastern cottontails do not dig their own dens
(other than nest holes) but use burrows dug by other species [27].  In
winter when deciduous plants are bare eastern cottontails forage in less
secure cover and travel greater distances [1].  Eastern cottontails
probably use woody cover more during the winter, particularly in areas
where cover is provided by herbaceous vegetation in summer [9].  In
Florida slash pine flatwoods, eastern cottontails use low saw-palmetto
(Serenoa repens) patches for cover within grassy areas [38].

Most nest holes are constructed in grasslands (including hayfields) [1].
The nest is concealed in grasses or weeds.  Nests are also constructed
in thickets, orchards, and scrubby woods [27].  In southeastern Illinois
tallgrass prairie, eastern cottontail nests were more common in
undisturbed prairie grasses than in high-mowed or hayed plots [64].  In
Iowa most nests were within 70 yards (64.2 m) of brush cover in
herbaceous vegetation at least 4.0 inches (10.2 cm) tall.  Nests in
hayfields were in vegetation less than 7.8 inches (20.0 cm ) tall [30].
Average depth of nest holes is 4.7 inches (120 mm), average width 5
inches (126 mm), and average length 7 inches (180 mm).  The nest is
lined with grass and fur [9,48].


FOOD HABITS : 
The diet of eastern cottontails is varied and largely dependent on
availability.  Eastern cottontails eat vegetation almost exclusively;
arthropods have occasionally been found in pellets [15].  Some studies
list as many as 70 [15], 100 [16], or 145 plant species [39] in local
diets.  Food items include bark, twigs, leaves, fruit, buds, flowers,
grass seeds, sedge fruits, and rush seeds.  Numerous studies of local
eastern cottontail diet are summarized by Chapman and others [9].  There
is a preference for small material:  branches, twigs, and stems up to
0.25 inch (0.6 cm) [26].  Leporids including eastern cottontails are
coprophagus, producing two types of fecal pellets one of which is
consumed.  The redigestion of pellets greatly increases the nutritional
value of dietary items [9,17,48].

Summer Diet:  Eastern cottontails consume tender green herbaceous
vegetation when it is available.  In many areas Kentucky bluegrass (Poa
pratense) and Canada bluegrass (P. compressa) are important dietary
components [10,39].  Other favored species include clovers (Trifolium
spp.)  and crabgrasses (Digitaria spp.) [34].  In Connecticut important
summer foods include clovers, alfalfa, timothy (Phleum pratense),
bluegrasses (Poa spp.), quackgrass (Elytrigia repens), crabgrasses,
redtop (Agrostis alba), ragweed (Ambrosia psilostachya), goldenrods
(Solidago spp.), plantains (Plantago spp.), chickweed (Stellaria media),
and dandelion (Taraxacum officinale).  Eastern cottontails also consume
many domestic crops [27].

Fall, Winter, and Early Spring Diet:  During the dormant season, or when
green vegetation is covered with snow, eastern cottontails consume
twigs, buds, and bark of woody vegetation [34].  In Connecticut
important winter foods include gray birch (Betula populifolia), red
maple, and smooth sumac (Rhus glabra) [15].


PREDATORS : 
Major predators of eastern cottontail include domestic dog (Canis
familiaris), foxes (Vulpes and Urocyon spp.), coyote (C. latrans),
bobcat (Lynx rufus), domestic cat (Felis cattus), weasels (Mustela
spp.), raccoon (Procyon lotor), mink (M. vison), great horned owl (Bubo
virginianus), barred owl (Strix varia), hawks (Falconiformes), corvids
(Corvidae), and snakes [26,27].  In the Southwest cottontails including
eastern cottontail comprise 7 to 25 percent of the diets of northern
goshawk (Accipiter gentilis) [50].  In Texas eastern cottontails are
preyed on by coyotes more heavily in early spring and in fall than in
summer or winter [2].  In southwestern North Dakota cottontails (both
eastern and desert cottontail [Sylvilagus auduboni]) were major prey
items in the diets of bobcats [62].

Predators that take nestlings include raccoon, badger (Taxidea taxus),
skunks (Mephitis and Spilogale spp.), and Virginia opossum (Didelphis
marsupialis) [52].  In central Missouri eastern cottontails comprised
the majority of biomass in the diet of red-tailed hawks (Buteo
jamaicensis) during the nesting season [60].  In Pennsylvania the chief
predator of eastern cottontails is the great horned owl [52].

Juvenile eastern cottontails are rare in the diet of short-eared owls
(Asio flammeus) [33].  Trace amounts of eastern cottontail remains have
been detected in black bear (Ursus americanus) scat [29].


MANAGEMENT CONSIDERATIONS : 
The eastern cottontail has major economic importance as a game species
for both meat and fur production; it is also of economic importance as
prey of furbearers (bobcat, coyote, foxes etc.) [25,34].  Since eastern
populations remain relatively stable they are an important prey item for
the endangered red wolf (Canis rufus) breeding population at Gulf
Islands National Seashore [55].  Eastern cottontails are potential prey
for the endangered black-footed ferret (Mustela nigripes), particularly
in prairie dog (Cynomys spp.) colonies [31].  The eastern cottontail is
common in suburban to urban areas and is an economically important pest
there as well as in in farmlands and tree plantations [26,48].
Transplantation of eastern cottontail populations has had impacts on
other species; in New England the decline of the New England cottontail
(Sylvilagus transitionalis) has been attributed at least in part to
eastern cottontail introduction [9,48].

Population Status:  In Illinois eastern cottontails increased in
abundance with agricultural development in the early postsettlement
period [42].  However, more recent changes in intensity of agriculture,
which have reduced the amount and size of areas of suitable habitat,
have contributed to a decline in eastern cottontail populations [1,25].
Reduced eastern cottontail numbers are associated with the decrease in
the number and size of individual farms and the amount of land devoted
to hay and oats because of increased emphasis on more valuable grains
[19].  Other changes include reductions in grasslands, reductions in
stream and river bottom forests and woodlots, and plowing of weedy and
brushy pastures [1,25].  In Illnois population indices for the period
1956 to 1978 indicate declines of at least 70 percent statewide, and 90
to 95 percent in intensively farmed areas [19].  In Ohio eastern
cottontail abundance declined by 70 percent from 1956 to 1983 in spite
of efforts to maintain populations [7].  In Kentucky conversion of
pastures to tall fescue (Festuca arundinacea) has reduced eastern
cottontail reproductive rates because of the presence of an unpalatable
endophytic fungus (Acremonium ceonophialum) associated with the tall
fescue [25].  Boyd [7] reviewed causes of eastern cottontail population
declines.

Pest Control:  Lethal control methods (trapping, shooting) are expensive
and effective only in the short term.  Nonlethal control methods are
also expensive but often effective.  Exclosures and repellants are the
most effective methods to reduce damage by rabbits.  Silvicultural
practices that reduce cover in and around plantations, particularly on
roadsides, are the most effective way to reduce rabbit damage [26].

Habitat Management:  In most areas eastern cottontail habitat can be
improved by the interspersion of old fields with briar thickets and
creation of edge by breaking up large areas of monocultures.  Artificial
cover in the form of brush piles 13 to 20 feet (4-6 m) in diameter and 3
to 7 feet (1-2 m) high is effective for up to 5 years.  Shrub plantings
should include thorny species that maintain a low, dense cover
resembling multiflora rose (multiflora rose is not recommended because
of its propensity to spread into other areas [10]).  Prescribed fire can
be used to improve cover (see FIRE ECOLOGY AND MANAGEMENT) [1,9].  Any
activity that reduces cover, such as burning followed by grazing,
decreases habitat quality [1,10].

In southwestern ponderosa pine forests cottontail numbers can be
increased by management that encourages dense natural or artificial
regeneration, by the retention of piled slash, or by encouragement of
herbaceous and shrub growth after timber harvest [12,13].  In central
Louisiana eastern cottontails were present in longleaf pine (Pinus
palustris)-slash pine woodlands in slightly greater numbers in
regeneration stands than in sapling, sawtimber, or pole-size stands
[47].  In northern Georgia, forage biomass was greater on all
site-preparation treatments after timber harvest than on unlogged
control sites; harvested sites are potentially better habitat for
eastern cottontails, but eastern cottontails were not plentiful enough
on the site to distinguish between treatments [22].  Increased
cottontail numbers have been noted where clearcuts have increased cover
in the form of slash piles, increased production of herbaceous plants,
and Gambel oak sprouts.  Numbers also increased in areas with dense
ponderosa pine reproduction around 4 to 5 feet tall (1.2-1.5 m) [12].
Only agricultural land that was within 300 feet (91.4 m) of a woodlot
was used by eastern cottontails in southwestern Wisconsin [61].

Food availability is typically not the most important consideration in
eastern cottontail management since it is not usually considered a
limiting factor.  Eastern cottontails select suitable cover over
abundant food supply if cover and abundant food are not found together
[1].  Korschgen [39] asserted that placement of preferred food plants
near permanent cover improves eastern cottontail habitat and
productivity.


REFERENCES : 
NO-ENTRY

Related categories for Wildlife Species: Sylvilagus floridanus | Eastern Cottontail