Dipodomys venustus

Geographic Range

Dipodomys venustus is found in the coastal mountain range of central California, from the tip of the San Francisco peninsula to slightly north of Santa Barbara.

• Biogeographic Regions
• nearctic nearctic
  • native native

Habitat

This kangaroo rat is a burrowing rodent that usually dwells in soft, sandy, well-drained soil, where the associated vegetation generally consists of chaparral or chaparral interspersed with oak or digger pine.

The average rainfall in this range is about 75 cm, with the majority of it falling in the winter (November-March). The dry months are offset by a consistently present fog bank, which helps maintain moisture levels in the region.

D. venustus is found at elevations from sea level to 1,770 m. It typically inhabits slopes.

• Habitat Regions
• temperate temperate

• Terrestrial Biomes
• chaparral chaparral

Physical Description

D. venustus is a darkly colored, five-toed rodent that is medium-sized for its genus. By human standards, it is pretty cute, having large eyes set in a narrow face. The nose and ears are black. There are yellowish hairs on the back, which are more prominent on the sides, giving the flanks a lighter coloration. The cheeks and the ventrum are light colored.

Males weigh approximately 83 g (range 70 to 97 g) with females averaging about 82 g (range 68 to 96 g). There is sexual dimorphism in length, with males being longer (about 318.2 mm for males, compared with 313.5 mm for females), and having longer hind feet. The basal length of cranium, greatest length of cranium, maxillary arch spread, width of maxillary arch, greatest depth of cranium, greatest width of cranium, and zygomatic width are also larger in the males.

• Other Physical Features
• endothermic endothermic
• homoiothermic
• bilateral symmetry bilateral symmetry

• Sexual Dimorphism
• male larger

Reproduction

The mating system of this species has not been described. However, within the genus Dipodomys , there is a tendency for males and females to come together only for mating purposes. Males and females inhabit separate burrows. In some species, males may attract females using foot drumming.

Female D. venustus have one to two litters per year with two to four young per litter. Data on seasonality of breeding are limited, although one nest was excavated in late May in which a mostly helpless baby was found.

Although the gestation period of this species has not been reported, within the genus Dipodomys gestations generally range from 29-36 days. The average female cycle is about 12 days in length. Birth weights range from 3-6 g. Young typically remain n the nest for 4 or 5 weeks, and can reach reproductive maturity as young as 2 months of age.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• fertilization fertilization
• viviparous viviparous
• post-partum estrous

As in all mammals, the female provides extensive parental care, nursing the young until they are able to eat solid foods. Mothers care for their young in a nest within a burrow. Young are born helpless, so the nest environment is an important source of protection for them while they are young.

No male parental care has been reported for these animals, and the males and females live separately.

• Parental Investment
• altricial altricial
• pre-hatching/birth
  • provisioning
    • female
  • protecting
    • female
• pre-weaning/fledging
  • provisioning
    • female
  • protecting
    • female

Lifespan/Longevity

Information on the lifespan of this species was not available in the literature. However, one member of the same genus, D. ordii lived for nearly 10 years in captivity.

Behavior

D. venustus does not venture far from its burrow. Little else has been observed. Members of the genus tend to be solitary and territorial, with only one adult occupying a single burrow.

Unlike most members of the genus Dipodomys , D. venustus is water dependent. These animals become emaciated and will die if they do not have access to water, or have to subsist on dry seeds. This is apparently a primative characteristic for the genus.

• Key Behaviors
• fossorial fossorial
• saltatorial saltatorial
• nocturnal nocturnal
• motile motile
• sedentary sedentary
• solitary solitary

Home Range

The home range size for these animals is not known.

Communication and Perception

Little is known about the communication of D. venustus . However, within the genus, animals are known communicate with a combination of vocalizations, foot drumming, and scents. Dustbathing is common in some species, and allow animals to both spread their scents and detect the scents of others.

• Communication Channels
• visual visual
• tactile tactile
• acoustic acoustic
• chemical chemical

• Other Communication Modes
• scent marks scent marks
• vibrations vibrations

• Perception Channels
• visual visual
• tactile tactile
• acoustic acoustic
• vibrations vibrations
• chemical chemical

Food Habits

Dipodomys venustus feeds primarily on the ripe seeds of annual plants, with the achene (a small, dry, one-seeded fruit) of H. grandiflora (telegraph weed) being a preferred food. D. venustus makes one or several caches of seeds in its primary burrow, and makes many storage caches within close proximity of the entrance to its burrow. This species consumes very little free water, getting the vast majority from food. However, unlike other members of the genus, it must have some access to free water.

• Primary Diet
• herbivore herbivore
  • granivore granivore

• Plant Foods
• seeds, grains, and nuts

• Foraging Behavior
• stores or caches food stores or caches food

Predation

Information is limited regarding the predators of D. venustus . D. venustus bones are not found in the pellets of associated barn owls, suggesting D. venustus is not part of the owl's diet. However, it is likely that these animals fall prey to many of the standard predators of rodents in the region, including hawks, falcons, owls, coyotes, fox, bobcats, and house cats.

Ecosystem Roles

D. venustus contributes in dispersing seeds. It is probably also important to the diets of some predators.

• Ecosystem Impact
• disperses seeds

Economic Importance for Humans: Positive

none

Economic Importance for Humans: Negative

D. venustus minimally consumes the seeds of cultivated crops.

• Negative Impacts
• crop pest

Conservation Status

D. venustus is not threatened or endangered

Additional Links

Encyclopedia of Life

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Scott Remke (author), Humboldt State University, Brian Arbogast (editor), Humboldt State University.

References

Best, 1992. *Dipodomys venustus*. Mammalian Species , 403: 1-4.

Church, 1969. Evaporative Water Loss and Gross effects of Water Privation in the Kangaroo Rat, *Dipodomys venustus*. Journal of Mammalogy , 50: 514-523.

Hawbecker, 1940. The Burrowing and Feeding Habits of *Dipodomys Venustus*. Journal of Mammalogy , 21: 388-396.

Nowak, R. 1999. Walker's Mammals of the World, Sixth Edition . Baltimore and London: The Johns Hopkins University Press.

Wilson, D., S. Ruff. 1999. The Smithsonian Book of North American Mammals . Washington and London: Smithsonian Institution Press.