Meriones unguiculatusMongolian jird

Geographic Range

Mongolian gerbils, or Mongolian jirds, occur naturally in the highlands of Inner Mongolia. They are also found in adjacent parts of southern Siberia and northern China, including Sinkiang and Manchuria provinces.

Currently Meriones unguiculatus is a popular housepet and is widely used in research. It can be found worldwide in a variety of locales and environments (Agren et al. 1989).

Habitat

Mongolian gerbils live in the highlands in Inner Mongolia. Climate in these regions is extreme, temperatures can vary from -40 degrees Celsius in the winter to 50 degrees Celsius in the summer. These areas are characterized by low annual precipitation (less than 230 mm a year) and a long winter (October to April).

Gerbils, or jirds, live in clay or sandy deserts, grasslands, scrub, arid steppes, and mountain valleys.

They live in family groups in small burrows dug into soft soil. Gerbils build burrows near a plant to take advantage of the support of the plant's roots (Agren et al. 1989). M. unguiculatus burrows are characterized by one nest and one to two storerooms, the burrows extend 0.45-0.60 meters underground and average 4cm in diameter.

Physical Description

Mongolian jird body length averages 120 mm long, tail length may range up to 120 mm. The fur is thin, with grey roots, a yellow shaft, and a black tip. Ventral fur is white and their unfurred claws reveal their pink/white skin.

Males are slightly larger than females, with males averaging 60 grams and females averaging 50-55 grams (van Veen 1999).

  • Range mass
    52 to 133 g
    1.83 to 4.69 oz
  • Average mass
    96 g
    3.38 oz
  • Average basal metabolic rate
    0.546 W
    AnAge

Reproduction

Wild mongolian gerbils breed between February and October, producing up to three litters. The estrus cycle lasts 4-6 days and a post-partum estrus can occur. Gestation lasts between 19 and 30 days. Litter size varies between 1 and 12, but averages 4 to 7. Newborn young weigh about 2.5 grams each and weaning occurs at 20-30 days. Sexual maturity is reached at between 65 and 85 days old and breeding can continue until 20 months of age, though average lifespan in the wild is 3-4 months (Nowak, 1991).

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual
  • Average number of offspring
    5
    AnAge
  • Average gestation period
    25 days
    AnAge
  • Average age at sexual or reproductive maturity (female)
    Sex: female
    43 days
    AnAge
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    36 days
    AnAge

Lifespan/Longevity

Behavior

Mongolian gerbils have some interesting behaviors. Each family group of gerbils seems to be led by an alpha male that is larger than the rest. Family and territory size (anywhere from 325 to 1550 square meters) seems to be dependent on alpha male size. There are 2-3 times more females than males in any family but family size rarely exceeds 20 animals.

Gerbils spend much of their time foraging. They also become inactive during the hottest and coldest part of the day to conserve energy. Activity levels also decrease during the coldest and warmest parts of the year. This behavior seems to be innate as even domesticated gerbils show signs of inactivity during the hottest and coldest parts of the year and day.

Gerbils sandbathe to maintain pelage health, especially to remove excess oil. Oils in the fur help to absorb sunlight and regulate body temperature.

Mating behavior is characterized by the male chasing a female while stomping his feet. Females allow mating after a period of courtship (van Veen 1999). Foot stomping is also used to warn other gerbils of danger (Ehrenstein and Bruckmann 1998).

Communication and Perception

Food Habits

Mongolian gerbils feed mainly on mugwort (Artemisia sieversiana and A. commutata). Saltwort (Salsola collina), bristle grass (Setaria viridis), and lyme grass (Leymus chinensis) are also eaten.

Gerbils conserve both water and fat extremely well. They conserve water by producing a highly concentrated urine and dry feces.

Captive mongolian gerbils eat a wide variety of foods, including grains, grasses, and some fruits and vegetables. (Agren et al. 1989)

Economic Importance for Humans: Positive

Mongolian gerbils are useful research animals and have become very popular in the pet trade. They are easy to take care of, get along well with other gerbils (when introduced to each other early), require very little maintenance, and are tremendously cute and fun to play with. The first documented pet Mongolian gerbil lived in the United Kingdom in 1961. (van Veen 1999).

Economic Importance for Humans: Negative

Mongolian gerbils are not extensive agricultural pests. Escaped captive gerbils may become established in new areas and pose a threat to native wildlife through competition and disease introduction. Gerbils, similar to other rodents, may serve as disease vectors.

(Agren et al. 1989)

Conservation Status

Mongolian gerbil populations are stable.

Other Comments

Gerbils are tremendously intelligent animals, both in their natural environments and in captivity. Their adaptations to their harsh natural enviroments makes them suited for living in many parts of the world.

Contributors

Jack Chen (author), University of California, Irvine, Rudi Berkelhamer (editor), University of California, Irvine.

Glossary

Palearctic

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

World Map

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.

motile

having the capacity to move from one place to another.

mountains

This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.

native range

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

sexual

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

tactile

uses touch to communicate

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.

References

Agren, G., Q. Zhou, W. Zhong. 1989. Ecology and social behaviour of Mongolian gerbils, Meriones unguiculatus, at Xilinhot, Inner Mongolia, China. Animal Behavior, 37: 11-27.

Ehrenstein, E., V. Bruckmann. 1996. "Gerbil Behavior" (On-line). Accessed October 31, 2000 at http://home.wtal.de/ehr/gerbils/behavior.htm.

IUCN, "The 2000 IUCN Red List of Threatened Species. Database Search." (On-line). Accessed (Date Unknown) at http://redlist.cymbiont.ca/search.asp.

Naumov, N., V. Lobachev. 1999. "Ecology of the Desert Rodents of the USSR. (Jerboas and Gerbils)" (On-line). Accessed October 31, 2000 at http://home.wtal.de/ehr/gerbils/wild.htm.

Nowak, R. 1991. Walker's Mammals of the World, Fifth Edition. Baltimore and London: The Johns Hopkins University Press.

Prakash, I., P. Ghosh. 1975. Rodents in Desert Enviroments. The Hague: The Hague.

van Veen, K. 1999. "Mongolian Gerbil Subjects" (On-line). Accessed October 31, 2000 at http://users.bart.nl/~fredveen/subjects1.htm.