Dipodomys ordiiOrd's kangaroo rat

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Geographic Range

Dipodomys ordii are the most widespread of all Kangaroo rats. They are found through much of western North America from Saskatchewan to Mexico. The Kansas plains, Great Sandhills of Sakatchewan and the California sagebrush are all common habitats. (Banfield 1974; La Flamme 2000) (Banfield, 1974; La Flamme, 2000)

Habitat

D. ordii can be found on the riverbanks and the Great Sand Hills of Saskatchewan, throughout the Kansas plains, and the deserts of the southwestern United States (Banfield 1974; La Flamme 2000; Walker 1975).

In general, D. ordii prefers arid climates with sparse vegetation covering the sandy ground. Open ground is better for this animal, as it has been observed that an increase in grass cover leads to a decrease in population. Their burrows are rarely located in hard and gravelly soils and they are one of the few animals that are able to establish in shifting dunes (Banfield 1974; Davis and Schmidly 1994). (Banfield, 1974; Davis and Schmidly, 1994; La Flamme, 2000; Walker, 1975)

Physical Description

Total length ranges from 210-365 mm in males, and 208-360 mm in females. Tail length is, on average, 129 mm in males and 127 mm in females. The long tail is dark on top with two white bands on each side tapering to a grey tuft of longer hairs at the end. Ord's kangaroo rats have small forelimbs and long, strong hindlegs which are modified for jumping (Feldner 1996; Walker 1975).

Coloration of the long silky fur is rich and tawny on top with a scattering of black hairs along the middorsal line. D. ordii have distict white markings which include underparts of the feet, upper lip, spots above the eyes and across the hips.

There are no pelage differences between males and females but there are seasonal variations in weight for all D. ordii. Their weight peaks around mating season (Banfield 1974). (Banfield, 1974; Feldner, 1996; Walker, 1975)

  • Sexual Dimorphism
  • sexes alike
  • Range mass
    55 to 96 g
    1.94 to 3.38 oz
  • Average basal metabolic rate
    0.339 W
    AnAge

Reproduction

D. ordii are solitary animals that will only let potential mates approach during the mating seasons in spring and fall. Exact timing of mating seasons varies geographically. Females breed only when there is a favorable moist season, few breed during drought.

During estrus, which lasts for a few days, this species will pursue each other playfully. With an approximate gestation period of a month and sexual maturity at 2 months, the population can expand rapidly after a favorable season. (Banfield 1974) (Banfield, 1974)

  • Breeding interval
    Ord's kangaroo rats breed when conditions are appropriate, with abundant food sources for both mother and young.
  • Breeding season
    Breeding seasons are typically in the spring and fall, but vary throughout the range of Ord's kangaroo rats.
  • Average number of offspring
    3
    AnAge
  • Average gestation period
    29 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    2 months
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    61 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    2 months

Lifespan/Longevity

Behavior

Ord's kangaroo rats are solitary and allow only their mate to approach during mating seasons. During other times of the year encounters may result in fights involving aerial collisions of the hind legs used to slash at each other (La Flamme, 2000).

Kangaroo rats are nocturnal. During the day these animals will protect their homes using their hind legs to pack the burrow entrace with sand. Sealed entrances and deep burrows allow these rats to survive a wide range of temperatures (Banfield 1974; Davis and Schmidly 1994).

All four legs are used for travelling slowly but the hind legs are used in a jumping fashion in order to move long distances rapidly. Forelimbs are primarily used for picking up food and other materials while the animal rests on it's hindlegs and large tail (La Flamme 2000; Walker 1975). (Banfield, 1974; Davis and Schmidly, 1994; La Flamme, 2000; Walker, 1975)

Communication and Perception

Kangaroo rats have a keen sense of smell, extraordinary hearing, and good night vision.

D. ordii individuals have an oil secreting gland located between the shoulders. They bathe regularily in sand to prevent the fur from becoming oily and matted. Secretions from the gland also allow D. ordii to distinguish individuals and sexes (Walker 1975).

Ord's kangaroo rats rarely make any vocal calls, the sounds that are made are usually soft squeaks. Instead they use their hind legs to make loud thumping noises in their burrow when the entrance is disturbed (Feldner 1996; Walker 1975). (Feldner, 1996; Walker, 1975)

Food Habits

The diet of Ord's kangaroo rats is primarily composed of seeds. These seeds are gathered in fur lined cheek pouches for transport back to their burrows for storage. D. ordii forage for up to 25 yards from their burrow entrance. In the summer, D. ordii also feed on grasshoppers and moths. Water retention is very efficient in Ord's kangaroo rats and they use the water produced from metabolism for their bodily requirements. As a result, they have very little need for water consumption and will only drink water when absolutely necessary.

(Feldner 1996; Walker 1975) (Feldner, 1996; Walker, 1975)

  • Animal Foods
  • insects
  • Plant Foods
  • seeds, grains, and nuts

Predation

In encounters with particularily threating predators, D. ordii will turn around and face away from the enemy and use their hind legs to spray sand into the enemy's eyes. D. ordii can evade predators with long jumps measuring up to 2 meters long. (La Flamme, 2000; Walker, 1975)

Economic Importance for Humans: Positive

Unknown

Economic Importance for Humans: Negative

Ord's kangaroo rats do not adversely affect humans over most of their range. However in areas of Texas, D. ordii are reputed to do damage by gathering the seeds of newly planted crops (Davis and Schmidly 1994). (Davis and Schmidly, 1994)

  • Negative Impacts
  • crop pest

Conservation Status

Ord's kangaroo rats are one of the most common kangaroo rats. In western Canada, however, D. ordii is considered vulnerable.

Contributors

Poh-lin Teh (author), University of Toronto.

Glossary

Nearctic

living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

bilateral symmetry

having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.

chemical

uses smells or other chemicals to communicate

desert or dunes

in deserts low (less than 30 cm per year) and unpredictable rainfall results in landscapes dominated by plants and animals adapted to aridity. Vegetation is typically sparse, though spectacular blooms may occur following rain. Deserts can be cold or warm and daily temperates typically fluctuate. In dune areas vegetation is also sparse and conditions are dry. This is because sand does not hold water well so little is available to plants. In dunes near seas and oceans this is compounded by the influence of salt in the air and soil. Salt limits the ability of plants to take up water through their roots.

endothermic

animals that use metabolically generated heat to regulate body temperature independently of ambient temperature. Endothermy is a synapomorphy of the Mammalia, although it may have arisen in a (now extinct) synapsid ancestor; the fossil record does not distinguish these possibilities. Convergent in birds.

fossorial

Referring to a burrowing life-style or behavior, specialized for digging or burrowing.

granivore

an animal that mainly eats seeds

herbivore

An animal that eats mainly plants or parts of plants.

iteroparous

offspring are produced in more than one group (litters, clutches, etc.) and across multiple seasons (or other periods hospitable to reproduction). Iteroparous animals must, by definition, survive over multiple seasons (or periodic condition changes).

motile

having the capacity to move from one place to another.

native range

the area in which the animal is naturally found, the region in which it is endemic.

nocturnal

active during the night

pheromones

chemicals released into air or water that are detected by and responded to by other animals of the same species

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

reproduction that includes combining the genetic contribution of two individuals, a male and a female

solitary

lives alone

stores or caches food

places a food item in a special place to be eaten later. Also called "hoarding"

tactile

uses touch to communicate

temperate

that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).

terrestrial

Living on the ground.

territorial

defends an area within the home range, occupied by a single animals or group of animals of the same species and held through overt defense, display, or advertisement

tropical savanna and grassland

A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.

savanna

A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.

temperate grassland

A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.

vibrations

movements of a hard surface that are produced by animals as signals to others

visual

uses sight to communicate

viviparous

reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.

References

Banfield, A. 1974. The Mammals of Canada. Toronto: University of Toronto Press.

Burt, W., R. Grossenheider. 1964. A Field Guide to the Mammals. Boston: Houghton Mifflin Company.

Davis, W., D. Schmidly. 1994. "Ord's Kangaroo Rat (The Mammals of Texas -online edition)" (On-line). Accessed Nov 19, 2000 at http://www.nsrl.ttu.edu/tmot1/dipoordi.htm.

Feldner, J. 1996. "Kangaroo Rats (Desert Usa.com)" (On-line). Accessed Nov 15,2000 at http://www.desertusa.com/aug96/du_krat.html.

La Flamme, J. 2000. "Kangaroo Rat (Canadian Museum of Nature)" (On-line). Accessed Nov 15, 2000 at http://www.nature.ca/notebooks/english/kangarat.htm.

Walker, E. 1975. Mammals of the World. Baltimore: John Hopkins University Press.