Pachyuromys duprasifat-tailed gerbil

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Geographic Range

The natural distribution of fat-tailed gerbils, Pachyuromys duprasi, is the northern portion of desert west of the Nile Delta in Egypt. This rodent also extends into Libya, Tunisia, and Algeria. (Barker, 2003; Helmy and Osborn, 1980)

Habitat

Fat-tailed gerbils are found in sand sheets that are graced with vegetation. They occur south of the western Mediterranean coastal desert, sometimes in rocky deserts. Often their habitat is compared to what Ranck (1968) describes as "transitional deserts which run roughly parallel to the more lush coastal plains". They live in burrows down to 1 meter in depth. These gerbils are known to occupy burrows of other rodents as well. (Barker, 2003; Helmy and Osborn, 1980; Ranck, 1968)

Physical Description

Fat-tailed gerbils have fur that is long and fluffy. These gerbils are described as having a round body with fairly large, oval-shaped eyes and pink ears that are positioned low on the head. The main color of their fur varies between gray and tan with dorsal hairs sometimes tipped with black. Coloration of fur varies with subspecies in different ranges. The hairs of the underside and feet are white. The palms and soles of their feet are partly haired and their ears are sparsely haired. The tails of these animals are notable and different from that of other gerbils. The tails are shorter than their heads and bodies, are thick and club-shaped, and lack brush hairs. These tails function in storing fat and water. The general health of a specimen is determined by the thickness of the tail, for if the tail is skinny, it is proposed that the animal may not be getting enough food and nutrients. The average adult head and body length is approximately 108 mm; tail 58 mm; foot 23 mm; ear 14 mm; occipitonasal length 34 mm; and weight 36.5 g. (Barker, 2003; Helmy and Osborn, 1980)

The cranial characteristics of fat-tailed gerbils include an elongate skull with enormously inflated auditory bullae. The external auditory meatus is swollen. A large suprameatal triangle is an excellent identifying characteristic for P. duprasi. The meatal lip of fat-tailed gerbils is swollen as well, and an accessory tympanum is present. The zygomatic process of this rodent is complete but the supraorbital ridge is noted to be poorly developed. (Barker, 2003; Helmy and Osborn, 1980)

The teeth of fat-tailed gerbils are comprised of upper incisors, which are grooved on the anterior surface. Molars are rooted and the first upper and lower molar in juveniles appear to be tuberculate, becoming laminate in adults. The second upper and lower molars show no evidence of tubercles. The third molars of this rodent are simple, lacking folds. The enamel pattern is similar to that of Meriones crassus rather than Gerbillus. (Barker, 2003; Helmy and Osborn, 1980)

  • Sexual Dimorphism
  • sexes alike
  • Average mass
    36.5 g
    1.29 oz
  • Average mass
    40 g
    1.41 oz
    AnAge
  • Average length
    108 mm
    4.25 in

Reproduction

The mating system of wild fat-tailed gerbils was not found in the lieterature examined here. In captivity, the mating ritual of fat-tailed gerbils is particularly unusual. Apparently, males and females stand on their hind legs and wrestle while making shrieking noises. This mating ritual is often mistaken for fighting. (Barker, 2003; Flower, 1932; Helmy and Osborn, 1980)

The gestation period for P. duprasi is between 19 to 22 days. In captivity litters between 3 and 9 young were born during the months of April though November. Pups are weaned at around 3 to 4 weeks of age. (Barker, 2003; Flower, 1932; Helmy and Osborn, 1980)

  • Breeding interval
    Fat-tailed gerbils can breed up to three times a year.
  • Breeding season
    In captivity, breeding occurs between April and November.
  • Range number of offspring
    3 to 9
  • Average number of offspring
    4.5
    AnAge
  • Range gestation period
    19 to 22 days
  • Range weaning age
    3 to 4 weeks
  • Range age at sexual or reproductive maturity (female)
    3 to 6 months
  • Range age at sexual or reproductive maturity (male)
    3 to 6 months

Young are altricial. At birth, they are blind, naked, and vulnerable. Mothers care for their offspring, in some type of nest, probably in a burrow, until they are able to fend for themselves. Fat-tailed gerbil pups are weaned at around 3 to 4 weeks of age. The role of the male in parental care has not been noted. (Barker, 2003; Stead, 1996)

  • Parental Investment
  • no parental involvement
  • altricial
  • pre-fertilization
    • protecting
      • female
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
    • protecting
      • female
  • pre-independence
    • protecting
      • female

Lifespan/Longevity

Captive specimens of the fat-tailed gerbil have a life span between 5 and 7 years. It is likely that wild individuals so not live so long. The age of P. duprasi may be determined by how worn the molars are and the closing of the skull sutures. (Barker, 2003; Helmy and Osborn, 1980)

  • Range lifespan
    Status: captivity
    7 (high) years
  • Typical lifespan
    Status: captivity
    5 to 7 years

Behavior

Fat-tailed gerbils are the most docile of Egyptian rodents. When captured, these animals give little effort to escape and rarely bite. However, with other members of their species, they can be aggressive and sometimes cannibalistic. Females have been known to eat their young. In captivity, owners have noted that when they fight, they bite each other's tails, often forming scars. Fat-tailed gerbils are nocturnal. In the wild, they most often become active at dusk, although individuals are active intermittently all day and night. Owners of captive animals claim they are active for very short periods time in between longer periods of sleep. They appear to be social and are found in colonies, but can be solitary as well. (Barker, 2003; Helmy and Osborn, 1980)

Home Range

The size of home ranges of these animals was not found.

Communication and Perception

The males of P. duprasi have scent glands on their stomachs to mark territories. Tactile and visual communication are important, especially during mating, when a form of sparring occurs between males and females. Vocalizations are also involved. (Barker, 2003; Stead, 1996)

Food Habits

Fat-tailed gerbils are mostly insectivorous. In the wild, researchers have also observed these animals feeding on plants of Anabasis articulata and Artemisia monosperma. In captivity, these rodents are fed meal worms, crickets, beetles, grain, various vegetables, Gerbil Mix, and even chopped meat. (Barker, 2003; Helmy and Osborn, 1980)

  • Animal Foods
  • insects
  • terrestrial worms
  • Plant Foods
  • leaves
  • seeds, grains, and nuts

Predation

Predation upon P. duprasi has not been well documented. An anti-predator adaptation may be the fossorial behavior of this species. Also, this rodent's light-colored fur may act as a camouflage mechanism with the desert soil color.

  • Anti-predator Adaptations
  • cryptic

Ecosystem Roles

There was no information found that was published on the role of P. duprasi in the ecosystem. However, since these animals are fossorial, they may act as aerators for the desert soil. Fat-tailed gerbils most likely serve as a prey species for birds. They probably impact insect and plant populations upon which they prey.

Economic Importance for Humans: Positive

Fat-tailed gerbils are an increasingly popular house pet for humans. They are docile, easy to care for, and they tend to get along well with other gerbils. People that own fat-tailed gerbils as pets claim that they are very cute and fun to play with. (Barker, 2003; Stead, 1996)

Economic Importance for Humans: Negative

There was no information found on the adverse affects of P. duprasi on humans. However, escaped captive fat-tailed gerbils may become established in new areas and compete with native wildlife. Fat-tailed gerbils, similar to other species of rodents, may serve as disease vectors. This gerbil may also pose a "threat" to humans, for they occasionally bite, although it is difficult to imagine such a small animal inflicting much damage through a bite.

Conservation Status

Fat-tailed gerbils are not listed by IUCN or CITES.

Other Comments

Most information is based on the subspecies found in Egypt, P. d. natronensis.

Contributors

Nancy Shefferly (editor), Animal Diversity Web.

Sheunna Barker (author), University of Wisconsin-Stevens Point, Chris Yahnke (editor, instructor), University of Wisconsin-Stevens Point.

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

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

crepuscular

active at dawn and dusk

cryptic

having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.

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.

fertilization

union of egg and spermatozoan

fossorial

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

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.

nocturnal

active during the night

pet trade

the business of buying and selling animals for people to keep in their homes as pets.

scent marks

communicates by producing scents from special gland(s) and placing them on a surface whether others can smell or taste them

seasonal breeding

breeding is confined to a particular season

sedentary

remains in the same area

sexual

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

social

associates with others of its species; forms social groups.

soil aeration

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

solitary

lives alone

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).

terrestrial

Living on the ground.

vibrations

movements of a hard surface that are produced by animals as signals to others

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

Barker, J. 2003. "Fat-tailed Gerbil" (On-line). National Gerbil Society. Accessed June 21, 2004 at http://www.gerbils.pwp.blueyonder.co.uk/gerbils/duprasi.htm.

Flower, S. 1932. Notes on the Recent Mammals of Egypt. Proc. Zool. Society: 368-450.

Helmy, I., D. Osborn. 1980. Fieldiana Zoology: The Contemporary Land Mammals of Egypt (Including Sinai). Chicago, Illinois: Field Museum of Natural History.

Ranck, G. 1968. The Rodents of Libya: taxonomy, ecology, and zoogeographical relationships. Nat. Mus. Bull.: 157.

Stead, L. 1996. "Duprasi or Fat-Tailed Gerbils" (On-line ). Accessed 02 December 2002 at http://www.webcom.com/~lstead/rodents/duprasi.html.