The Panamint kangaroo rat (''Dipodomys panamintinus'') 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. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found else ...

to the

Mojave Desert The Mojave Desert ( ; mov, Hayikwiir Mat'aar; es, Desierto de Mojave) is a desert in the rain shadow of the Sierra Nevada mountains in the Southwestern United States. It is named for the indigenous Mojave people. It is located primarily ...

in eastern

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 ...

and western

Nevada Nevada ( ; ) is a U.S. state, state in the Western United States, Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. N ...

, 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 Continental United States, primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., ...

Description

The Panamint kangaroo rat is considered medium-sized for its

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...

. It is pale clay-colored with blackish patches around the face. The tail is extremely long, on average 140% of its body length and contains a white stripe with a heavy tuft of hair at the end. The species is named after an area of its range in the

Panamint Valley The Panamint Valley is a long basin located east of the Argus and Slate ranges, and west of the Panamint Range in the northeastern reach of the Mojave Desert, in eastern California, United States. Geography The northern end of the valley is i ...

and

Panamint Range The Panamint Range is a short rugged fault-block mountain range in the northern Mojave Desert, within Death Valley National Park in Inyo County, eastern California. Dr. Darwin French is credited as applying the term Panamint in 1860 during his ...

Mountains just west of

Death Valley Death Valley is a desert valley in Eastern California, in the northern Mojave Desert, bordering the Great Basin Desert. During summer, it is the hottest place on Earth. Death Valley's Badwater Basin is the point of lowest elevation in Nort ...

. Their common name derives from their bipedal form. They morphologically adapted to use

bipedal Bipedalism is a form of terrestrial locomotion where an organism moves by means of its two rear limbs or legs. An animal or machine that usually moves in a bipedal manner is known as a biped , meaning 'two feet' (from Latin ''bis'' 'double' ...

hopping as their primary means of locomotion. The Panamint kangaroo rat can be distinguished from other species of the genus because the hind feet have five toes which varies in comparison to other members which have four toes on their hind feet. Sexual dimorphism is present where males tend to be larger than females in body size. A notable characteristic of the Panamint kangaroo rat is the fur lined cheek pouches that it uses to obtain large quantities of food. These pouches keep the food separate from the mouth which aids in preventing moisture loss.

Ecology

Range and habitat

The Panamint kangaroo rat has a rather restricted distribution in comparison to some species of the genus. It is centered in

Great Basin The Great Basin is the largest area of contiguous endorheic watersheds, those with no outlets, in North America. It spans nearly all of Nevada, much of Utah, and portions of California, Idaho, Oregon, Wyoming, and Baja California. It is noted fo ...

bush desert in western

and east of the Sierra Nevada mountains in California with a long extension southward into the western

. They tend to live at higher elevations between . Panamint kangaroo rats occupy holes in small mounds of sand that have accumulated around clumps of brush. In the Panamint Mountains, one animal may occupy a burrow that has 12 or more tunnels, the mouths of which are connected on the surface by well-defined runways. Home range size varies throughout the year, peaking in February and July.

Diet

''Dipodomys panamintinus'' is a

granivore Seed predation, often referred to as granivory, is a type of plant-animal interaction in which granivores (seed predators) feed on the seeds of plants as a main or exclusive food source,Hulme, P.E. and Benkman, C.W. (2002) "Granivory", pp. 132 ...

that lives on metabolic water. Their diet tends to vary with the seasons, but tends to primarily consist of seeds that are high in carbohydrates. It gathers large bunches of seeds and packs them into fur-lined cheek pouches. Some examples of seeds and other food sources which they obtain are pinion pine, juniper berries, green shoots of grass, insects, and mesquite. They tend to partake in both scatter

hoarding Hoarding is a behavior where people or animals accumulate food or other items. Animal behavior ''Hoarding'' and ''caching'' are common in many bird species as well as in rodents. Most animal caches are of food. However, some birds will a ...

(single or small clusters of seeds buried in the ground surface) and larder hoarding (deposition of seeds in burrows and chambers). This hoarding style affects seed dispersal throughout the environment in which they live. They rely heavily on

olfactory The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, ...

senses to be able to locate these seed deposits for utilization during times of food scarcity. Based on the physiological aspect of their sense of smell, Panamint kangaroo rats seem to have a better time locating these hoards during dry weather.

Behavior

The Panamint kangaroo rat is

nocturnal Nocturnality is an animal behavior characterized by being active during the night and sleeping during the day. The common adjective is "nocturnal", versus diurnal meaning the opposite. Nocturnal creatures generally have highly developed sens ...

and does not hibernate. It tends to be active throughout the year except when limited by snow cover. The species is solitary and separate except during

estrus The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous ...

Locomotion

The

form of locomotion that the Panamint kangaroo rat utilizes is very specialized. They will move by various means depending on the environmental situation they are in. For example, when undisturbed, a slowly moving animal travels by quadrupedal hopping, bipedal hopping or, bipedal walking and when frightened, the hopping changes into erratic bipedal leaps in order to avoid predators. Panamint kangaroo rats are excellent swimmers, their large hind feet give them considerable agility in the water. The Panamint kangaroo rat's hop is about the same length of its body. The availability of water and nutrition can have an effect on the activity of the animal.

Mating and reproduction

Responses between males and females change cyclically as a female passes through

. Continuous proximity of the male may cause the female to stop cycling so, successful breeding demands that both sexes dwell separately, coming together for mating with only a brief paring interval. Males home ranges will become broader during spring for mating. The height of breeding season is between February and March. Litter size ranges between 3-4 young.

Physiology

Because of the dry desert environment that the Panamint kangaroo rat inhabits, it has developed a specialized way to metabolize water from their food that they obtain. These kangaroo rats are able to excrete urine that is extremely concentrated as a means to retain water. When deprived of water, it only produces a small drop of urine every 1–2 hours. Surprisingly these kangaroo rats possess very limited means of temperature regulation, despite living in an environment characterized by wide extremes of temperature. Above 35 °C the Panamint kangaroo rat utilizes their burrows to help maintain homeothermy.

References

{{Taxonbar, from=Q737126 Dipodomys Fauna of the Mojave Desert Mammals of the United States Rodents of North America Death Valley National Park Panamint Range Fauna of California Least concern biota of the United States Mammals described in 1894 Taxonomy articles created by Polbot