Rhombomys opimus

Geographic Range

Great gerbils, Rhombomys opimus , are distributed through out Central Asia, from the Caspian Sea to Southern Mongolia and North-Central China. In the Middle East they are found in Iran, Afghanistan, and western Pakistan. Great gerbil are also said to inhabit areas of Southwestern Russia.

• Biogeographic Regions
• palearctic palearctic
  • native native

Habitat

Great gerbils inhabit the deserts of Central Asia. They are most abundant in sand and clay deserts, usually in foothill and mountain areas. This species of gerbil prefers subsandy soil where it creates elaborate multichambered burrows. These burrows are found from 1.5-2.5 m below the surface. These animals will also inhabit agricultural areas. They dammage crops because they hoard grains and vegetation for the winter.

• Habitat Regions
• temperate temperate

• Terrestrial Biomes
• desert or dune desert or dune

• Other Habitat Features
• agricultural agricultural

Physical Description

This is the largest species of gerbil with a body length ranging from 150 to 200 mm and a tail length of 130 to 60 mm. The upper body is yellowish-orange, or dark grayish-yellow, matching the sandy deserts they inhabit. Great gerbils spend the winter under snowpack and has thick, dense, soft fur and a fairly long-haired tail. The body is stocky. The claws are long and sharpto help it dig its burrows.

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

Reproduction

The mating system of this species has not been reported.

Rhombomys opimus is gregarious and often individuals will burrow close to one another. This forms a network of burrowing tunnels, creating a colony. Females are polyestrous and depending on the conditions will breed multiple times during a season. The breeding season, which comes after the rainy season, lasts from April to September and each female will produce on average two or three litters. The gestation period is 23 to 32 days and the litter size ranges from 1 to 14 young although the average observed litter size in the wild is 4-7 young. Females can reach sexual maturity at 3 to 4 months of age.

• Key Reproductive Features
• iteroparous iteroparous
• seasonal breeding seasonal breeding
• gonochoric/gonochoristic/dioecious (sexes separate)
• sexual sexual
• viviparous viviparous

Little has been reported about the parental care of this species. Females nurse their young, which are probably altricial. The role of the male in parental care is not known.

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

Lifespan/Longevity

Lifespan varies from male to female. The males maximum lifespan is 2 to 3 years and the female lives 3 to 4 years.

Behavior

R. opimus lives in large colonies composed of many subgroups. These subgroups are believed to be offspring of mother/father pairs within the colony. During the winter these large groups huddle together to keep warm when temperatures become critically low outside. They rely on the stable underground temperatures (20 to 25 C) which exist in their burrows. This species does not hibernate, although its activity is reduced during the winter months. These gerbils are mainly diurnal.

• Key Behaviors
• terricolous
• fossorial fossorial
• diurnal diurnal
• motile motile
• colonial colonial

Home Range

The home range size of these animals has not been reported.

Communication and Perception

Communication in this species has not been described. However, because they are somewhat social, it is likely that they have some tactile communication. As in other rodents, they probably use some vocalizations and visual cues to communicate also.

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

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

Food Habits

R. opimus feeds on a variety of plants, seeds, fruits, stems, roots, bulbs, and shrubs. Living in desert habitats, this gerbil must rely on metabolic water found in plants. Seeds permeated with dew are collected at night and brought back to the burrow. Relatively high humidity inside the burrow produces improved water content in the seeds. In areas where the winter snow pack may cover the burrow entrance for weeks, this species is known to store food. This food is stored in compartments located inside the burrow. Also, when food is abundant these gerbils are known to store leaves in a pile on the surface next to the entrance. Piles have been measured as high as three feet tall and ten feet long.

• Primary Diet
• herbivore herbivore
  • folivore folivore
  • frugivore frugivore
  • granivore granivore
• coprophage coprophage

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

Predation

Great gerbils have a number of anti-predator adaptations that they utilize in order to survive the harsh enviroments they occupy. Their sandy colored backs blend in with the desert floor making it difficult for air-pursuit predators to locate them. They have a large middle ear, allowing them to hear low-frequency sounds made by the wings of owls and raptors, and helping them to evade such predators. These animals have large eyes, which enable them to have an open field of vision. R. opimus is mostly diurnal, foraging during low light hours to avoid predators. The tuft of hair on the end of the tail is believed to be a predator decoy. A bird of prey might hit the tail, allowing the gerbil enough time to escape.

Ecosystem Roles

R. opimus provides a source of food for predators like owls and hawks. The burrow systems they create may also affect the ecosystems they inhabit, and enhance soil aeration. because they cache food, they probably play some role in seed dispersal.

• Ecosystem Impact
• disperses seeds
• soil aeration soil aeration

Economic Importance for Humans: Positive

This species is trapped for its skins in some places.

• Positive Impacts
• body parts are source of valuable material

Economic Importance for Humans: Negative

This species is considered a pest through out its entire range. These gerbils have been known to damage crops, irrigation cannals, and embankments of roads and railways. In Central Asia these mammals carry disease like the plague and the skin disease Leishmaniasis.

• Negative Impacts
• crop pest
• causes or carries domestic animal disease causes or carries domestic animal disease

Conservation Status

Additional Links

Encyclopedia of Life

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Mathew Nannizzi (author), Humboldt State University, Brian Arbogast (editor), Humboldt State University.

References

Macdonald, D. 1984. The Encyclopedia of Mammals . New York: Facts on File Publications.

Nowak, R. 1999. Walkers Mammals of the World, Sixth Edition . Baltimore, MD: Johns Hopkins University Press.

Wilson, D., D. Reeder. 1993. Mammal Species of the World . Smithsonian Institution.