The Dulzura kangaroo rat, or San Diego kangaroo rat (''Dipodomys simulans'') is a species of

rodent Rodents (from Latin , 'to gnaw') are mammals of the order Rodentia (), which are characterized by a single pair of continuously growing incisors in each of the upper and lower jaws. About 40% of all mammal species are rodents. They are n ...

in the family

Heteromyidae Heteromyidae is a family of rodents consisting of kangaroo rats, kangaroo mice, pocket mice and spiny pocket mice. Most heteromyids live in complex burrows within the deserts and grasslands of western North America, though species within th ...

. It is found in

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

, and in the Colorado Desert and elsewhere in

California California is a state in the Western United States, located along the Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the most populous U.S. state and the 3rd largest by area. It is also the m ...

in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...

. It is a common species and the IUCN has assessed its status as being of "

least concern A least-concern species is a species that has been categorized by the International Union for Conservation of Nature (IUCN) as evaluated as not being a focus of species conservation because the specific species is still plentiful in the wild. T ...

Taxonomy

The Dulzura kangaroo rat was at one time thought to be

conspecific Biological specificity is the tendency of a characteristic such as a behavior or a biochemical variation to occur in a particular species. Biochemist Linus Pauling stated that "Biological specificity is the set of characteristics of living organis ...

with the agile kangaroo rat (''Dipodomys agilis'') but the two are now recognised as being separate species; there is significant differences between them in their morphology, and their chromosome counts differ, with ''D. agilis'' having a karyotype of 2n=62 and ''D. simulans'' having 2n=60.

Description

This is a medium-sized

kangaroo rat Kangaroo rats, small mostly nocturnal rodents of genus ''Dipodomys'', are native to arid areas of western North America. The common name derives from their bipedal form. They hop in a manner similar to the much larger kangaroo, but developed t ...

with a length of including a tail of . The upper parts are dark brown and the underparts white. There are five toes on the hind feet which are long (some related species have four toes). The tail is well-haired and has a dark streak along its under surface. Like other kangaroo rats, this species proceeds in a series of hops, using only its hind legs, and stabilising itself with its long tail. The front legs are used for digging.

Distribution and habitat

The species is native to southern California and northwestern Mexico, being present in much of

. Its typical habitat is sandy and gravelly soils in semi-desert, dry grassland and scrub, and chaparral near the coast; it is also sometimes found in forests of

pine A pine is any conifer tree or shrub in the genus ''Pinus'' () of the family Pinaceae. ''Pinus'' is the sole genus in the subfamily Pinoideae. The World Flora Online created by the Royal Botanic Gardens, Kew and Missouri Botanical Garden accepts ...

oak An oak is a tree or shrub in the genus ''Quercus'' (; Latin "oak tree") of the beech family, Fagaceae. There are approximately 500 extant species of oaks. The common name "oak" also appears in the names of species in related genera, notably ''L ...

and fir.

Ecology

The Dulzura kangaroo rat lives in a burrow which has several entrances, some of which may be at the base of shrubs. It is nocturnal, spending the day in its burrow (often blocking up the entrances) and emerging for a few hours at night. It feeds mainly on seeds, but also eats green plant material and insects, its diet varying with what is available at the time of year. It carries its food back to the burrow in its cheek pouches. It is solitary, the female defending a territory against intruders. Breeding can take place at any time of year but is more common in winter or spring. There is a single litter in the year, usually consisting of two to four offspring.

Status

''D. simulans'' is described as common in the United States, with densities of up to 45 animals per hectare being reported. It is less abundant in Mexico but altogether the population is thought to be stable. No particular threats have been identified, and the

International Union for Conservation of Nature The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of nat ...

has assessed this kangaroo rat's conservation status as being of "

References

{{Taxonbar, from=Q1767490 Dipodomys Mammals of Mexico Mammals of the United States Rodents of North America Fauna of the Baja California Peninsula Fauna of the Colorado Desert Mammals described in 1904 Least concern biota of North America