Sylvilagus floridanus - Eastern Cottontail Rabbit 

Skull Pictures:      
Dorsal     Posterior mandible
Lateral    Ventral
Mandible

Physical Description:

The adult eastern cottontail is a mid-sized rabbit weighing approximately 900-1,800 g (2-4 lbs.) with a total length of 407-423 mm (16-17 in.).  Five toes are present on the forefeet, and four on the hind feet, which collectively measure anywhere from 90-100 mm (3-4 in.).  The dorsal portion of the body varies in color from grays to browns with the tips of each hair being white or silver giving the pelage a frosty look.  A distinct rust-colored patch can be seen on the nape of the neck and fronts of the forearms.  The ventral portions are browner on the proximal end moving to whitish gray-sandy white toward the distal end and hide four pairs of mammae.  The short, fluffy tail 26-47 mm (1-1¾ in.) in length is brownish above and white below and, is usually the most conspicuous part of the animal when it runs hence the common name, cottontail.  The cottontail undergoes two molts per year.  The spring molt, from mid-April to mid-July results in a darker flat or short summer coat.  The fall molt from mid-September to the end of October results in a prime or longer, grayer winter pelage (Chapman, Hockman and Ojeda, 1980).

 Distribution:

The eastern cottontail is the most common, and geographically widespread, of all North American rabbits.  It ranges from Costa Rica through Mexico, north to southern Manitoba and Quebec.  It is also found in the United States east of the Rocky Mountains in the Great Plains region New Mexico and Arizona, with the exception of Maine, a majority of New Hampshire and Vermont, and northeastern New York.  The rabbit is absent from parts of Louisiana’s coastal marsh as well (Wildlife Habitat Management Institute (U.S.) 1999).  It ranges through all of Wisconsin though scarce throughout the largely forest-dominated parts of the northern landscape.

Ontogeny and Reproduction:

Day-length is the basic mechanism controlling the onset of breeding, particularly in the males.  However, the frequency and extent of late-winter periods of warm and cold temperatures result in some variation in the onset of breeding from year to year (Chapman, Harman, and Samuel, 1977).  Colder than normal temperatures delay breeding, while warmer temperatures result in earlier breeding.  Each female produces several litters of two to six young during the breeding season, with most breeding occurring between March and August. Gestation is 26 to 28 days.  A female may breed again before her young are a day old.  Shortly before the litter arrives, the female cottontail digs a nest cavity in the ground about 15 to 18 cm deep.  This depression is usually hidden by tall grass or bushes.  The nest, or form, is lined with grass and tufts of fur plucked from the female's own body.  Newborn cottontails are pink in color, blind, and helpless. The altricial newborn weighs 25-30 g (1oz) and grows at the rate of 2.5 g/day (0.1oz/day) (Kurta, 1995).  After her litter is born, the female cottontail stays in a form near the nest, only visiting her young to nurse once or twice a day to reduce detection by predators.  When the female leaves the nest, she covers the young with grass and fur for warmth, and scratches leaves over the nest to conceal it.  Young cottontails are well-furred within a week.  They open their eyes between six and nine days, and leave their nests at about 2 weeks of age.  Many cottontails born in the spring breed for the first time as soon as the summer preceding that spring, hence the saying “multiply like rabbits”. 

Ecology and Behavior:

The eastern cottontail is an edge species attracted to field and cover edges and early successional or weedy habitats (Wildlife Habitat Management Institute (U.S.) 1999).

The eastern cottontail can be found almost anywhere two types of cover meet; however, it prefers a mixture of grass, forbs such as wildflowers or weeds, and dense thorny shrubs. It most prefers ground cover that is a mixture of open areas which harbor any dense brushy vegetation near by. Fence rows, shelterbelts, stream sides, and roadsides are all potential locations where this type of habitat may be found.

The cottontail is solitary. Seldom are two or more found together, except for the young, and for mating cottontails. All habitat components needed by an animal are found in its home range. The female cottontail's home range is 1 to 15 acres (9.4 ha.) in size, while the males may be as much as 100 acres (41 ha.) or more. A cottontail must rely on shrubs or woody cover for escape cover. The rabbit uses above-ground structures called "forms" as well as abandon underground holes of badger, prairie dog and woodchuck for escape and shelter. Forms are pockets the rabbit creates by trampling small areas of grass and small shrubs.  Primarily nocturnal, it uses these forms or nests at night and during daytime or any rest periods throughout the year, even during the reproductive period. The cottontail uses underground holes for emergency escape throughout the year and during winter for shelter.

Basically a vegetarian, the cottontail eats primarily grasses and legumes such as clover and lespedezas during the growing season. Cottontails consume a considerable amount of forbs such as dandelions, ragweed and prickly lettuce, as well as numerous crops such as soybeans, wheat and corn.  During the non-growing season cottontails consume mainly, young shoots, buds. When more preferred foods are scarce its diet may shift to include twigs and/or bark of raspberry, red maple, aspens, black cherry, staghorn sumac, and many others.  When other foods are not available, it may resort to eating non-plant foods such as snails or carrion.

The eastern cottontail has a plantigrade foot posture and runs using saltatorial locomotion. Cottontails may attain a speed of about 29 km per hour, although this cannot be maintained for more than 0.8 km (Barry and Olcott, 2000). Cottontails depend more on ducking and dodging than upon speed to escape their enemies, and will often travel in a circuitous route and then return to near their starting place. Eastern cottontails do not take to water readily, but they can swim if necessary.  Hearing is acute, and cottontails can move their ears at will to catch sounds from various directions. The cottontails have a very excellent sense of smell and sight as well.

Remarks:

The cottontail’s genus name Sylvilagus, combines the Latin word silva, meaning “forest,” and the Greek word lagos, meaning “hare” as the historically inhabited swamps and hardwood boreal forests (Wildlife Habitat Management Institute (U.S.), 1999).

Literature Cited:

Barry, R. E., and S. P. Olcott. 2000, Environmental Correlates of Geographic Variations in Body Size of the eastern cottontail (Sylvilagus floridanus): Journal of Mammalogy. 81:986–998.

Chapman, J. A., A. L. Harman, and D. E. Samuel. 1977, Reproductive and physiological cycles in the cottontail complex in western Maryland and nearby West Virginia: Wildlife Monographs. 56:1–73.

Chapman, J.A., J.G. Hockman and M.M. Ojeda. 1980. Sylvilagus floridanus. Mammalian Species no.136. The American Society of Mammalogists.

Dice, L. R. 1927, The transfer of game and fur-bearing mammals from state to state, with special reference to the cottontail rabbit: Journal of Mammalogy. 8:90–96.

Hoffmeister, D. F., and E. G. Zimmerman. 1967, Growth of the skull in the cottontail (Sylvilagus floridanus) and its application to age determination: The American Midland Naturalist. 78:198–206.

Kurta, A. 1995. Mammals of the Great Lakes Region. The University of Michigan Press, Michigan.

Wildlife Habitat Management Institute (U.S.) 1999. Eastern cottontail (Sylvilagus floridanus) Madison, MS: USDA, Natural Resource Conservation Service.

Reference written by Weston Schmidt, Biol 378: Edited by Chris Yahnke.
Page last updated 4-29-04.