Jumping Mice Birch Mice and Jerboas: Dipodidae

The Dipodidae family includes small to medium-sized rodents that walk on two or four legs. In general, their back legs are slightly or much longer than their front legs. They have long tails, and the jerboas' tails often have a distinctive black-and-white "banner" at the end. These mammals' fur is either coarse or soft and colors range from soft brown to brownish yellow to purplish-brown. The Dipodidae rodents range in length from 1.8 to 9 inches (4.5 to 23 centimeters) and weigh from 0.2 to 15 ounces (6 to 415 grams). The birch mice and jumping mice walk on four legs and are small, mouselike creatures with long tails and small, narrow heads. Birch mice have four legs of equal length, while the back legs of jumping mice are somewhat longer than their front legs. Both birch mice and jumping mice have short, blunt claws. Jerboas can be small or medium sized, and jump or walk on their back legs. Unlike the birch mice and jumping mice, which are mainly nocturnal but are sometimes active during the day, jerboas are strictly nighttime creatures. They can run very quickly through sparse brush. Their heads are large, with wide muzzles and flat snouts, and they have large eyes for better nighttime vision. Jerboas have compact, short bodies with short front legs and long, strong back legs. They can have either long or short claws and three, four, or five toes. All members of the Dipodidae family are remarkable for their jumping ability—probably an adaptation for evading predators in open country. Many of the mammals can cover 10 feet (3 meters) in a single jump, using their long tails to balance. In most species, the three central bones of the foot are fused, creating a single bone that provides major strength and support.