The European rabbit (Oryctolagus cuniculus) is the sole member of the Oryctolaus rabbit genus. These rabbits feature brownish-gray fur all over their bodies except their bellies, which have white fur. As its name suggests, the European rabbit is native to the European continent. The social colonies for European rabbits are called "warrens." In the winter, European rabbit warrens limit themselves to small groups. The population of warrens increases in the summer since they need large numbers to defend their territory.
Cottontail rabbits are in the rabbit genus Sylvilagus. This genus includes rabbit species such as the marsh rabbit, swamp rabbit, desert cottontail, New England cottontail and eastern cottontail -- the most common rabbit in North America. A common physical characteristic for all cottontail rabbits is their stubby white tail, which resembles a cotton ball. For most of their lives, cottontails are solitary animals. However, cottontails gather together for mating and raising their offspring. These rabbits also form social hierarchies which usually consist of an alpha male and several female cottontails.
Volcano rabbits (Romerolagus diazi) are endemic to Central Mexico's Chichinautzin Mountains, a chain of extinct volcanoes. These rabbits are semisocial, meaning they gather in groups of two to five specimens. The only breeding specimens in a volcano rabbit group are the alpha male and the primary breeding female. All other members of the group do not breed, but are available to defend their territory. Volcano rabbits have small, round ears and their fur is yellowish brown. These rabbits are able to live at elevated habitats of over 13,000 feet.
The pygmy rabbit (Brachylagus idahoensis) is the smallest rabbit in North America; the adult weight of pygmy rabbits is approximately 1 lb. These rabbits live in the United States' Great Basin, which includes states in the Pacific Northwest and Mountain West regions of the country. According to the U.S. Fish and Wildlife Service, groups of pygmy rabbits tend to breed at the same time in a particular area. Pygmy rabbits are one of the only North American rabbit species to dig their own burrows; the burrows are used for breeding and shelter.