Rhombomys opimusgreat gerbil

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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. (Wilson and Reeder, 1993)

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. (Nowak, 1999)

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. (Nowak, 1999)

  • Average mass
    285 g
    10.04 oz
    AnAge
  • Range length
    210 to 330 mm
    8.27 to 12.99 in

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. (Nowak, 1999)

  • Breeding interval
    Females can produce two or three litters per year.
  • Breeding season
    Breeding occurs between April and September.
  • Range number of offspring
    1 to 14
  • Average number of offspring
    4-7
  • Average number of offspring
    5
    AnAge
  • Range gestation period
    23 to 32 days
  • Range age at sexual or reproductive maturity (female)
    3 to 4 months
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    105 days
    AnAge

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. (Nowak, 1999)

  • Parental Investment
  • altricial
  • 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. (Wilson and Reeder, 1993)

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. (Macdonald, 1984; Nowak, 1999)

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.

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. (Nowak, 1999)

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. (Macdonald, 1984)

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.

Economic Importance for Humans: Positive

This species is trapped for its skins in some places. (Nowak, 1999)

  • 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. (Macdonald, 1984; Nowak, 1999)

Conservation Status

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

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

Glossary

Palearctic

living in the northern part of the Old World. In otherwords, Europe and Asia and northern Africa.

World Map

acoustic

uses sound to communicate

agricultural

living in landscapes dominated by human agriculture.

altricial

young are born in a relatively underdeveloped state; they are unable to feed or care for themselves or locomote independently for a period of time after birth/hatching. In birds, naked and helpless after hatching.

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.

causes or carries domestic animal disease

either directly causes, or indirectly transmits, a disease to a domestic animal

chemical

uses smells or other chemicals to communicate

colonial

used loosely to describe any group of organisms living together or in close proximity to each other - for example nesting shorebirds that live in large colonies. More specifically refers to a group of organisms in which members act as specialized subunits (a continuous, modular society) - as in clonal organisms.

coprophage

an animal that mainly eats the dung of other animals

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.

diurnal
  1. active during the day, 2. lasting for one day.
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.

female parental care

parental care is carried out by females

folivore

an animal that mainly eats leaves.

fossorial

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

frugivore

an animal that mainly eats fruit

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.

seasonal breeding

breeding is confined to a particular season

sexual

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

soil aeration

digs and breaks up soil so air and water can get in

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).

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

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.