Wild Things: Desert cottontail (Sylvilagus audubonii)
The desert cottontail is one of three New Mexico rabbits, along with the eastern and mountain cottontails. The desert cottontail occurs throughout the state, through Colorado, Wyoming, Montana, and Arizona, as well as parts of California, Nevada, Utah and Texas. Desert cottontails are smaller than their eastern cousins, reaching up to 17 inches in length and about 2.5 pounds. Females are somewhat larger than males and have smaller home ranges. Females of many mammal species tend to remain around natal areas whereas males often roam more widely.
Cottontail rabbits are classified in the genus Sylvilagus, as opposed to hares, which are in the genus Lepus. Hares, like the common Jackrabbit, are larger than cottontails, have longer ears and legs, can leap farther and run much faster.
The desert cottontail is found in dry grasslands and shrubby forests like piñon-juniper woodlands. The diet is vegetarian and consists mainly of grasses, though leaves, bark, fruits, and succulent cactus pads are also taken. Much of needed water is derived from plant matter and dew, but they will also drink from natural sources and from supplemental water provided in arid habitats, as shown in the photo. Cottontails also demonstrate the rather unexpected behavior of re-ingesting their own feces, a behavior termed coprophagia, which allows to them extract maximum nutrition from foods consumed.
Desert cottontails cope with extreme heat by sheltering in shrubby shade or burrows during the heat of the day and feeding at night or at dawn and dusk, a crepuscular activity pattern. They use burrows dug by other mammals, like woodchucks, or scratch out depressions of their own, similar to behavior seen in dogs.
These rabbits are prolific, females producing two to four, and up to six, litters per year. Each litter may have up to six young. Infants are naked and with eyes closed at birth, an altricial pattern, differing from hares which are fully furred at birth and active, a birth style termed precocial. But they are vulnerable to many predators, such as coyotes, bobcats, mountain lions, snakes, birds of prey, and others. Many more are killed by cars on roadways, by sport hunters, and by domestic dogs and cats. Their primary defense is running to escape. Otherwise they may remain still and hope to avoid detection when a predator is near. If discovered they may suddenly jump straight up, possibly surprising a predator and deterring an attack. Armadillos use this same predator avoidance behavior when alarmed, but it does not serve them well when on a roadway and a vehicle passes overhead.
Desert cottontail populations can be impacted during dry periods of vegetation shortage through competition with Jackrabbits. They eat the same foods, and while cottontails are not shy around Jackrabbits, the Jacks eat much more than cottontails and can diminish vegetation supplies. That being said desert cottontail populations are abundant and not under any conservation concern.
James Taulman is a semi-retired research wildlife biologist, having worked with the U.S. Forest Service research branch and taught zoology, ecology, and other courses in several university positions. He lives in the East Mountains, and explores natural areas observing native wildlife and conducting independent research projects. Search for James Taulman on Youtube to see wildlife videos.