KANGAROO RAT

small, jumping desert rodent, genus Dipodomys, related to the pocket mouse. There are about 20 kangaroo rat species, found throughout the arid regions of Mexico and the S and W United States. Kangaroo rats have large, mouselike heads with big eyes, external fur-lined cheek pouches for food storage, and extremely long, tufted tails. In many species the tail is longer than the combined head and body length. The total length, including the tail, is 10 to 15 in. (25–37.5 cm), depending on the species. The front limbs are very short and the back limbs extremely long and stiltlike. The animal moves by long leaps, like a kangaroo, using its tail for balance and as a rudder for turning at high speeds. Kangaroo rats have long silky fur, pale brown above and white beneath, with black and white tail tufts and black face markings. Solitary, nocturnal creatures, they live in burrows by day and forage at night for seeds, grass, and tubers. Active hoarders, they sometimes dry their food in shallow pits just below the surface of the ground, then dig it up and store it in their burrows. Like a number of other desert animals, the kangaroo rat has physiological mechanisms for conserving the water that it obtains from food or produces metabollically, so that it does not need to drink. A related genus, Microdipodops, is called the kangaroo mouse, or dwarf kangaroo rat. It is about 6 in. (15 cm) in total length and is found in the Great Basin of the W United States. Kangaroo rats are classified in the phylum Chordata, subphylum Vertebrata, class Mammalia, order Rodentia, family Heteromyidae.

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