The desert cottontail (Sylvilagus audubonii), also known as Audubon's cottontail, is a New World cottontail rabbit, and a member of the family Leporidae. Unlike the European rabbit (Oryctolagus cuniculus), they do not form social burrow systems, but compared with some other leporids, they are extremely tolerant of other individuals in their vicinity.

Cottontails give birth to their kits in burrows vacated by other mammals. They sometimes cool off, or take refuge in scratched out shallow created depressions of their own making, using their front paws like a back hoe. They are not usually active in the middle of the day, but can be observed foraging in the early morning, and early evening. Cottontails are rarely found out of their burrows looking for food on windy days, because the wind interferes with their ability to hear approaching predators, their primary defense mechanism.

Lifespan

thumb|left|Male desert cottontail at 8 weeks, and the same specimen at 16 months of age

thumb|Submissive posture anticipating food

The lifespan of a cottontail that reaches adulthood averages less than two years, depending on the location. Unfortunately for the cottontail, almost every local carnivore larger or faster than the lagomorph is its predator. Some predators, like snakes for example, are familiar with the area inhabited by the cottontails, and can catch and eat the young at will; the mother is unable to defend the litter. Although cottontails are highly active sexually, and mated pairs have multiple litters throughout the year, few young survive to adulthood. Those that survive grow quickly and are full grown at three months.

Description

The desert cottontail is quite similar in appearance to the European rabbit, though its ears are larger and are more often carried erect. It is social among its peers, often gathering in small groups to feed. Like all cottontail rabbits, the desert cottontail has a greyish-brown, rounded tail with a broad white edge and white underside, which is visible as it runs away. It also has white fur on the belly.

Adults are long and weigh anywhere from . The tail is , ears are long and the hindfeet are large, about in length.

Distribution and habitat

The desert cottontail is found throughout the Western United States from eastern Montana to western Texas, and in Northern and Central Mexico. It is particularly associated with the dry near-desert grasslands of the American southwest, though it is also found in less arid habitats such as pinyon-juniper forest. They also feed on the leaves and peas of mesquite, barks, fallen fruit, the juicy pads of prickly pear and twigs of shrubs. It rarely needs to drink, getting its water mostly from the plants it eats or from dew. Due to seasonality and changes in moisture conditions of their habitat, cottontails adjust their diets based on many influential factors that impact the seasonal changes of vegetation (i.e. moisture content, abundance, nutrition value, etc.). Like most lagomorphs, it is coprophagic, re-ingesting and chewing its own feces to extract the nutrients as effectively as possible.

Thermoregulation

Due to variable temperatures of their habitats, desert cottontails must be adequate thermoregulators to minimize water loss during the hotter seasons and require shaded areas of their environment to conduct evaporative water loss through thermal heat transfer. In open-desert areas, they can withstand for a short period extremely high temperatures of around , and have a large evaporative water loss capacity of around 1.5% body mass/hour, though cottontails can withstand longer in an ideal environment with shaded areas. To cope with evaporative heat loss, they do panting and undergo changes in production of their basal metabolic rate in relation to the ambient temperature of the environment. Ears of desert cottontails make up 14% of their body size and may help with thermoregulation.

Predators and threats

thumb|left|[[High Desert (California)|California High Desert cottontail on alert for predators]]

Many desert animals prey on cottontails, including birds of prey, mustelids, coyotes, bobcats, Mexican wolves, mountain lions, snakes, weasels, humans, and even squirrels, should a cottontail be injured or docile from illness. Alien species, such as cats and dogs, are also known predators, and also pose a threat. Cottontails can reach speeds of over . When defending itself against small predators or other desert cottontails, it will nudge with its nose, or slap with its front paws, usually preceded by a hop straight upwards as high as two feet when threatened or taken by surprise. When a season has been particularly dry, there is less plant life to go around. The cottontail does not fear the jackrabbit, in fact the jackrabbit is very skittish and will retreat from a confrontation in most instances. However, the black-tailed jackrabbit is much bigger, and consumes much more food at eating times.

Status and conservation

Since 1996, the desert cottontail has been rated of least concern on the IUCN Red List; it does not appear on the state or federal list of endangered species.

References

  • Desert USA page on the desert cottontail