Kangaroo Rat

Kangaroo rats move bipedally. Kangaroo rats often leap a distance of 7 feet, and reportedly up to 9 feet (2.75 m) at speeds up to almost 10 feet/sec, or 11 km/h (7 mph). They can quickly change direction between jumps. The rapid locomotion of the banner-tailed kangaroo rat may maximise energy cost and minimise predation risk. Its use of a "move-freeze" mode may also make it less conspicuous to nocturnal predators.

===Range and habitat=== Kangaroo rats live in arid and semiarid areas of western North America, particularly on sandy or soft soils They are sensitive to extreme temperatures and remain in their burrows during rain storms and other forms of inclement weather. They prefer areas of stony soils, including clays, gravel, and rocks, which are harder than soils preferred by some other species (like banner-tailed kangaroo rats). They do this in part by lowering their metabolic rate, which reduces the loss of water through their skin and respiratory system. Evaporation through the skin is the major route of loss. Merriam's kangaroo rats obtain enough water from the metabolic oxidation of the seeds they eat to survive and do not need to drink water at all. In contrast, banner-tailed kangaroo rats have more specific habitat requirements for desert grasslands with scattered shrubs; this species is also more threatened because of the decline in these grasslands. These are also dry areas but they tend to have more water available to them than Merriam's kangaroo rats.

Kangaroo rats are primarily seed eaters. They will, however, eat vegetation occasionally, and at some times of the year, possibly insects as well. Different species of kangaroo rat may have different seed caching strategies to coexist with each other, as is the case for the banner-tailed kangaroo rat and Merriam's kangaroo rat which have overlapping ranges.

(D. nitratoides nitratoides) at the California Living Museum in Bakersfield]] Kangaroo rats inhabit overlapping home ranges. These home ranges tend to be small with most activities within 200–300 ft and rarely 600 ft. Home range size can vary within species with Merriam's kangaroo rats having larger home ranges than banner-tailed kangaroo rats. Recently weaned kangaroo rats move into new areas not occupied by adults. Within its home range, a kangaroo rat has a defended territory consisting of its burrowing system.

Kangaroo rats live in complex burrow systems. The burrows have separate chambers used for specific purposes like sleeping, living, and food storage. The spacing of the burrows depends on the number of kangaroo rats and the abundance of food. Kangaroo rats also live in colonies that range from six to several hundred dens. The burrow of a kangaroo rat is important in providing protection from the harsh desert environment. To maintain a constant temperature and relative humidity in their burrows, kangaroo rats plug the entrances with soil during the day. When the outside temperature is too hot, a kangaroo rat stays in its cool, humid burrow and leaves it only at night. To reduce loss of moisture through respiration when sleeping, a kangaroo rat buries its nose in its fur to accumulate a small pocket of moist air. The burrows of Merriam's kangaroo rats are simpler and shallower than those of banner-tailed kangaroo rats. Banner-tailed kangaroo rats also mate in their burrows, unlike Merriam's kangaroo rats.

Kangaroo rats are generally solitary animals with little social organization. Kangaroo rats communicate during competitive interactions and courtship. They do cluster together in some feeding situations. Groups of kangaroo rats that exist are aggregations and colonies. Linear dominance hierarchies appear to exist among males but it is not known if this is the case for females. Winners of aggressive encounters appear to be the most active individuals.

Kangaroo rats have a promiscuous mating system. Their reproductive output is highest in summer following high rainfalls. During droughts and food shortages, only a few females will breed. The gestation period of kangaroo rats lasts 22–27 days. The young are born in a fur-lined nest in the burrows. They are born blind and hairless. For the first week, young Merriam kangaroo rats crawl, developing their hind legs in their second or third week. At this time, the young become independent. Banner-tailed kangaroo rats are weaned between 22 and 25 days. Offspring remain in the mound for one or six more months in the maternal caches.

* Family Heteromyidae ** Subfamily Dipodomyinae *** Dipodomys agilis (Agile kangaroo rat) *** Dipodomys californicus (California kangaroo rat) *** Dipodomys compactus (Gulf Coast kangaroo rat) *** Dipodomys deserti (Desert kangaroo rat) *** Dipodomys elator (Texas kangaroo rat) *** Dipodomys gravipes (San Quintin kangaroo rat) *** Dipodomys heermanni (Heermann's kangaroo rat) **** Dipodomys heermanni berkeleyensis (Berkeley kangaroo rat) *** Dipodomys ingens (Giant kangaroo rat) *** Dipodomys merriami (Merriam's kangaroo rat) *** Dipodomys microps (Chisel-toothed kangaroo rat) *** Dipodomys nelsoni (Nelson's kangaroo rat) *** Dipodomys nitratoides (Fresno kangaroo rat) *** Dipodomys ordii (Ord's kangaroo rat) *** Dipodomys panamintinus (Panamint kangaroo rat) *** Dipodomys phillipsii (Phillips's kangaroo rat) *** Dipodomys simulans (Dulzura kangaroo rat) *** Dipodomys spectabilis (Banner-tailed kangaroo rat) *** Dipodomys stephensi (Stephens's kangaroo rat) *** Dipodomys venustus (Narrow-faced kangaroo rat) **** Dipodomys venustus venustus (Santa Cruz kangaroo rat) **** Dipodomys venustus elephantinus (Elephant-eared or big-eared kangaroo rat) **** Dipodomys venustus sanctiluciae (Santa Lucia kangaroo rat)