The desert kangaroo rat (''Dipodomys deserti'') is a
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 na ...
species 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 the gen ...
that is found in desert areas of southwestern
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
.
It is one of the large
kangaroo rats
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 thi ...
, with a total length greater than and a mass greater than .
Range
The desert kangaroo rat is found in arid parts of southwestern
North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
, including
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 Highest temperature recorded on Earth, hottest place on Earth.
Death Valley's Badwater Basin is the ...
, the
Great Basin
The Great Basin is the largest area of contiguous endorheic basin, 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 ...
, 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 ...
, and portions of the
Sonoran Desert
The Sonoran Desert ( es, Desierto de Sonora) is a desert in North America and ecoregion that covers the northwestern Mexican states of Sonora, Baja California, and Baja California Sur, as well as part of the southwestern United States (in Arizona ...
.
[Rieth, W. and Boykin, K.G. (2004-2007) Southwest Regional Gap Analysis Wildlife Habitat Relationship - Desert Kangaroo Rat. New Mexico Cooperative Fish & Wildlife Research Unit, New Mexico State University. Accessed 2009-06-2]
/ref> Though kangaroo rats persist in a variety of soils, desert kangaroo rats live exclusively in areas with loose sand, often dune terrain. The places on this list constitute some of the most extreme deserts in the United States including 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 Highest temperature recorded on Earth, hottest place on Earth.
Death Valley's Badwater Basin is the ...
, which has the record for the hottest place on the continent.
Habitat
Desert kangaroo rats are denizens of desert areas with sandy soil; vegetation is typically sparse and consists of Larrea tridentata, creosote bush, a variety of grasses, and cacti
A cactus (, or less commonly, cactus) is a member of the plant family Cactaceae, a family comprising about 127 genera with some 1750 known species of the order Caryophyllales. The word ''cactus'' derives, through Latin, from the Ancient Greek ...
. Desert kangaroo rats live in burrow systems under slight mounds of soil 6-9m across;[ they sleep in a ]den
Den may refer to:
* Den (room), a small room in a house
* Maternity den, a lair where an animal gives birth
Media and entertainment
* ''Den'' (album), 2012, by Kreidler
* Den (''Battle Angel Alita''), a character in the ''Battle Angel Alita' ...
, which is sealed off at extreme temperatures, during the day.[ Groups of 6-12 widely spaced burrows may constitute a colony of this species, which is otherwise solitary.
]
Ecology
Foraging ecology
Seeds are the dominant component of the diet of desert kangaroo rats. The size of the seeds consumed by the species tends to be larger than seeds consumed by other, sympatric
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. An initially interbreeding population that splits into two or more distinct species sh ...
heteromyids.[ When presented with patches with variation in seed sizes and densities—which in combination vary total profitability—desert kangaroo rats tend to choose large-seed patches but reduce profitability of a set of patches to similar levels. Seed selection also appears correlated with nutritional content, with this species choosing seeds with high carbohydrate content. Although some kangaroo rats will consume green vegetation, desert kangaroo rats do not.][ Feeding occurs in fits and starts of movement and at relatively discrete locations, with an average distance of ~7 m (22 ft.) between stops.][
]
Water ecology
Most 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 thi ...
species live in arid environments and are known for their ability to make use of metabolic water
Metabolic water refers to water created inside a living organism through their metabolism, by oxidizing energy-containing substances in their food. Animal metabolism produces about 107-110 grams of water per 100 grams of fat, 41-42 grams of water ...
rather than requiring it from the environment. While the desert kangaroo rats do consume available water,[ the vast majority of their water requirements are met from byproducts of metabolic processes. Adaptation to very low quantities of water (free or metabolic) is highlighted by the very long water turnover times for the species, on the order of 2–3 weeks.
]
Special physiology
Kidneys
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 thi ...
s achieve the ability to be sustained on limited water by having incredibly derived kidneys. To remove waste without losing water, many species have developed mechanisms to concentrate their urine. This happens in the kidneys. There seems to be an inverse correlation of body mass to ability to concentrate urine. So naturally small rodents can persist in much more water deficient environments than larger animals. The desert kangaroo rat has a kidney structure very similar to those of other rodents, but it has much longer papilla
Papilla (Latin, 'nipple') or papillae may refer to:
In animals
* Papilla (fish anatomy), in the mouth of fish
* Basilar papilla, a sensory organ of lizards, amphibians and fish
* Dental papilla, in a developing tooth
* Dermal papillae, part of ...
(mammalian species). Papilla lengths, along with number of nephrons
The nephron is the minute or microscopic structural and functional unit of the kidney. It is composed of a renal corpuscle and a renal tubule. The renal corpuscle consists of a tuft of capillaries called a glomerulus and a cup-shaped structure ca ...
, play a crucial role in urine concentration.
Skull anatomy
Desert kangaroo rats have the longest nasal cavity of all the kangaroo rats, which allows for better water conservation. Hot, dry air can remove water from the body. The long nasal cavities reduce this water loss by cooling the air leaving the lungs. Cooling air releases moisture for reabsorption to the body so its loss can be avoided in a situation where water is a precious resource.
Group interaction
Foot drumming
Kangaroo rats drum their feet. Many different species of kangaroo rats' drumming pattern have been previously studied. They are thought to have evolved independently. Some use drumming to communicate location and other kangaroo rats respond in kind. This is not the case with the desert kangaroo rat. The desert kangaroo rat, living in a sand dune environment, has the highest level of food scarcity. When the desert kangaroo rat hears a drum from another rat, it comes out of its burrow and chases it away or engages in a rollover fight.
Predation
Desert kangaroo rats function under a high risk of predation for a variety of reasons. The first of which is they forage alone. They do not have a community of other rats to watch out for snakes or other predators. Secondly, in the desert, food is scarce and spread out, so desert rodents have to spend a substantial amount of time out of their holes searching for food. Because of these reasons, the desert kangaroo rat has had to evolve a few adaptations to protect itself.
Snakes
Though the more commonly studied Merriam's kangaroo rat
Merriam's kangaroo rat (''Dipodomys merriami'') is a species of rodent in the family Heteromyidae. The species name commemorates Clinton Hart Merriam. It is found in the Upper and Lower Sonoran life zones of the southwestern United States, Baja C ...
protects itself by predator avoidance, the desert kangaroo rat behaves more aggressively. In the case of a snake, the desert kangaroo rat drums its feet and moves within striking distance of the snake and kicks sand in the air. Though this is an incredibly dangerous activity for a small rodent, it does these things to let the snake know it is alert to its presence. Snakes are less likely to attack a rodent if the prey knows the snake is there. Desert kangaroo rats exclusively kick sand due to their natural environment being characterized by loose sand dunes. The desert kangaroo rat also uses its hind limbs to kick away attacking snakes in order to avoid being injected with venom.
References
{{Taxonbar, from=Q263504
deserti
North American desert fauna
Mammals of the United States
Fauna of the Mojave Desert
Fauna of the Sonoran Desert
Mammals described in 1887
Taxonomy articles created by Polbot