[5] In the 1950s and 1960s, the eastern cottontail was introduced to France and northern Italy, where it displayed a rapid territorial expansion and increase in population density.

[6] The population in the mountains of the southwestern United States and western Mexico is now thought to be a distinct species, the robust cottontail (S.

[8] 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.

[9] Habitat parameters important for eastern cottontails in ponderosa pine, mixed species, and pinyon (Pinus spp.

[9] Eastern cottontails do not dig their own dens (other than nest holes) but use burrows dug by other species such as woodchucks.

[4] In winter when deciduous plants are bare eastern cottontails forage in less secure cover and travel greater distances.

[11] In Florida slash pine flat woods, eastern cottontails use low saw-palmetto (Serenoa repens) patches for cover within grassy areas.

The kits develop the same coloring after a few weeks, but they also have a white blaze that goes down their forehead; this marking eventually disappears.

[16][17] There may be some slight variation in the body size of eastern cottontails, with weights seeming to increase from south to north, in accordance with Bergmann's rule.

[19] Due to Eastern Cottontails being so small and since they do not usually fight back they are easy prey for other animals such as coyotes, bobcats, and even foxes.

Forests, swamps, thickets, bushes, or open areas where shelter is close by are optimal habitation sites for this species.

Cottontails do not dig burrows, but rather rest in a form, a shallow, scratched-out depression in a clump of grass or under brush.

[20] 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.

[4] The nest is a slanting hole dug in soft soil and lined with vegetation and white fur from the mother's underside.

Young begin to move out of the nest for short trips by 12 to 16 days and are completely weaned and independent by four to five weeks.

Leporids including eastern cottontails are coprophagous, producing two types of fecal pellets, one of which is consumed.

[8][15] 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.

[15] In Connecticut, important winter foods include gray birch (Betula populifolia), red maple, and smooth sumac (Rhus glabra).

[24] In Kansas, the largest cause of mortality of radiotracked eastern cottontails was predation (43%), followed by deaths due to the research process (19%), and tularemia (18%).

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.

Due to their often large populations in Eastern North America, they form a major component of several predators' diets.

Major predators of eastern cottontail include domestic cats and dogs, foxes (Vulpes and Urocyon spp.

[4] Predators that take nestlings include raccoon, badger (Taxidea taxus), skunks (Mephitis and Spilogale spp.

[23] In central Missouri, eastern cottontails comprised the majority of biomass in the diet of red-tailed hawks (Buteo jamaicensis) during the nesting season.

In Texas, eastern cottontails are preyed on by coyotes more heavily in early spring and in fall than in summer or winter.

Trace amounts of eastern cottontail remains have been detected in black bear (Ursus americanus) scat.