About Sylvilagus audubonii (Baird, 1858)
The desert cottontail (Sylvilagus audubonii) is similar in overall appearance to the European rabbit, but it has larger ears that are more often held erect. This species is social, and individuals frequently gather in small groups to feed. Like all cottontail rabbits, it has a greyish-brown, rounded tail with a broad white edge and white underside that is visible when the rabbit runs away. It also has white fur on its belly. Adult desert cottontails measure 36 to 42 cm (14 to 17 in) in total length, and weigh between 700 and 1,200 g (1.5 to 2.6 lb). Their tails are 3.0 to 6.0 cm (1.2 to 2.4 in) long, their ears measure 6 to 9 cm (2.4 to 3.5 in) long, and they have large hindfeet that are about 7 to 9 cm (2.8 to 3.5 in) in length. There is very little sexual dimorphism in this species, but females are typically larger than males. Females also have much smaller home ranges: around 4,000 m² (1 acre), compared to around 61,000 m² (15 acres) for males. This species is found throughout the Western United States, ranging from eastern Montana to western Texas, and also occurs in Northern and Central Mexico. Its eastern range extends just barely into the Great Plains. To the west, its range reaches central Nevada, central and southern California, and Baja California, reaching the Pacific Ocean. Desert cottontails live at elevations of up to 1,830 m (6,000 ft). They are particularly associated with the dry near-desert grasslands of the American southwest, though they can also be found in less arid habitats such as pinyon-juniper forest. They are also frequently found in riparian zones within arid regions. An extremely wet winter leads to increased plant growth in the following spring, which causes desert cottontail populations to increase. However, if a wet winter is followed by an especially dry summer, existing plant life dries out quickly due to the extreme high temperatures of a desert summer. This has the opposite effect on populations, and can lead to hunger for the larger-than-usual desert cottontail population.
