Critters in the Garden
RSABG Volunteer, Nature Interpreter
Hopping Down the Desert Trail
If you’ve spent time in the desert you may have observed a small curious-looking creature hopping among the cactus. At first glance it sort of resembled a mouse on a pogo stick or maybe a rat with a caffeine high.
The kangaroo rat, genus Dipodomys, is a small rodent native to North America. Its large hind legs enable it to hop similar to the kangaroo, for which it is named. It is in no way related to that larger animal. Rather, it is related to the pocket mouse family, which includes kangaroo mice and pocket mice. The kangaroo rat inhabits many semi-arid to arid areas of California. One of our long-time volunteers reports a Google site listing 22 endemic North American species, many of which occur only in California! Most of those species are federally listed as special concern or endangered. Three are thought to be extinct. So far as is known, no kangaroo rats have ever been sighted by staff or volunteers at RSABG.
A pale yellow-buff to grey, depending on habitat, and with a white underbelly, the kangaroo rat can reach up to 14 inches in length and 8 inches tall. Many species are much smaller. Its large head is topped with very large ear capsules. The tail is longer than the body and ends with a dusky tufted tip.
Kangaroo rats are able to go their entire lives without drinking a drop of water. They derive enough water from their metabolism and food. Various kinds of seeds are diet mainstays although other vegetation as well as insects is eaten on occasion. Fur-lined cheek pouches are used for storing food during foraging. Food is gathered at night and stored in burrows.
Kangaroo rats live in complex burrow systems where separate chambers are used for specific purposes like sleeping, living and food storage. The burrows may extend as much as three or four feet underground and have multiple entrances. Desert burrows are evidenced by mounds found in the loose sandy soil under creosote and salt bushes. They provide protection from the harsh environment as well as from predators. However, coyotes often outsmart the kangaroo rats by digging them out! When the outside temperature is too hot, a kangaroo rat stays in its cool, humid burrow and leaves it only at night. When sleeping, it buries its nose in its fur to reduce loss of moisture.
Solitary animals, the males protect their territory by thumping opponents with their hind legs—sort of a miniature kickboxing match. In spite of who wins, the females tend to be promiscuous, thus insuring pregnancy. Mating can occur anywhere from January through July, usually at the peak of a rainy season when vegetation is abundant. During periods of drought only a few females will reproduce. Anywhere from one to six hairless blind infants are born in a fur-lined nest in the burrow. They learn to crawl quickly and develop their hind legs in their second or third week. Offspring can remain in the mound long after they are weaned; sometimes up to six or more months.
Folks driving in the desert at night are often startled by these animals appearing as small ghost-like creatures hopping across the pavement. Those of us who have spent nights in desert campgrounds know that kangaroo rats quickly learn to approach humans and accept tidbit handouts. They don’t appear to be disturbed by firelight or flashlights, providing opportunities to enjoy one of nature’s fascinating creatures.