Rhombomys opimus
great gerbil

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)

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)

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)

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)

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)

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)

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)

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

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.

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)

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)

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.

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

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)