Gerbillurus setzeriSetzer's hairy-footed gerbil

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Geographic Range

Gerbillurus setzeri is known throughout the Namib Desert in Africa. It ranges northward from the Kuiseb River to southern Angola.

(Dempster et. al., 1998; Wilson and Reeder, 1993)

Habitat

The hairy-footed gerbil is a desert animal. It is most frequently found on gravel plains without vegetation. These animals prefer dry river beds where top soil is loose and gravely and the lower layers are compact. If population densities become too high, G. setzeri will create burrows in sand dunes.

G. setzeri creates burrow systems below the surface of the desert to avoid the harsh desert climate. Below the surface, temperatures remain constant near 26 degrees Celsius during the day and at night. The humidity is also higher in these burrow systems.

Ninety percent of the burrow systems created by the hairy-footed gerbil are complex. Complex burrow systems contain numerous side branches and multiple entrances. For diagrams of these burrow systems see Downs and Perrin (1989). G. setzeri burrows are among the longest and deepest of the Gerbillurus species.

(Dempster et. al. 1998; Downs and Perrin, 1989)

Physical Description

Setzer's hairy-footed gerbil is one of the more robust gerbil species. Its head is larger than the head's of other Gerbillurus species and its body length is longer. The average total body length is around 233 millimeters with the tail comprising an average of 127.4 millimeters of the total length. The hairy-footed gerbil also has the largest auditory bullae of all Gerbillurus species.

As the common name implies, the soles of the feet are covered with hairs, an adaptation seen in many desert dwelling mammals. The pelage is long and thick and matches the color of the desert in which it lives. The dorsal side is a light brown or beige color. The ventral side, limbs, and mouth region are white. The hairy-footed gerbil has a long bushy tail ending in a tuft of gray hairs.

(Dempster et. al., 1998; Nowak, 1999)

  • Range mass
    30 to 40 g
    1.06 to 1.41 oz

Reproduction

Gerbillurus setzeri breeds year round. During copulation the male inserts a copulatory plug into the vagina. The gestation period for a litter is 21 days. Litters range from one to six altricial young. Their eyes are closed for the first 18 days of their lives. The young are weaned between 23 and 28 days after birth. Information about the postnatal development of Gerbillurus setzeri has been difficult to observe primarily because they are difficult to breed in captivity.

(Dempster, E.R. and Perrin M.R., 1991; Dempster et. al. 1998)

  • Key Reproductive Features
  • gonochoric/gonochoristic/dioecious (sexes separate)
  • sexual

Behavior

Many of the behaviors exhibited by Setzer's hairy-footed gerbil are adaptations to a harsh desert life. The hairy-footed gerbil is nocturnal and spends the day deep in its burrows away from the desert heat. When the shelter of the burrow does not keep the animals cool enough, they use their saliva to wet the area of fur on the neck and chest which then evaporates and cools the animal.

Gerbillurus setzeri frequently takes sandbaths. This consists of rolling and kicking up sand. They also dig, kicking sand with both front and hind feet.

The hairy-footed gerbil uses quadrupedal saltation (jumping) as a primary means of locomotion.

Ultrasonic vocalizations with frequencies of 39-49 kHZ are used in communication between animals. Young gerbils call to their mothers at frequencies of 45-55 kHZ. If the gerbils become alarmed they rapidly patter their back feet on the ground like drum rolls.

Many of the behaviors of G. setzeri have been recorded in a laboratory setting (Dempster and Perrin 1992). In experiments on social interactions between males and females, males fequently followed, sniffed, and mounted the females. Females tended to move away from the males and remain more inactive. Many interactions involved one animal exploring while the other watched. Both male and female subjects were observed to stand upright in aggressive and sexual encounters. Females were more aggressive in many of the experimental trials than males.

In lab settings Gerbillurus setzeri scatter hoards its food. This involves making several caches of food throughout a home range instead of having a cache at one specific site.

(Dempster, Dempster, and Perrin, 1992; Dempster et. al. 1998; Downs and Perrin, 1989; Nowak, 1999)

Communication and Perception

Food Habits

Gerbillurus setzeri consumes arthropods, plant material and seeds. Field researchers in central Namibia found leaves, dried flowers, dried fruits, seeds, chewed grass, remains of insects and beetles, and twigs in food caches from several G. setzeri burrows.

(Dempster et. al., 1998)

Economic Importance for Humans: Positive

Gerbils are popular pets.

Economic Importance for Humans: Negative

Many gerbil species do not come into contact with humans because they live deep in the deserts, but where humans and gerbils coexist, the gerbils can be very destructive to fields and crops. They can also carry deadly diseases.

(MacDonald, 1984)

Conservation Status

Gerbillurus setzeri lives in the Namib Desert which is inhospitable for most mammals, including humans. Therefore, this species is relatively safe from habitat destruction and habitat loss.

Other Comments

One of the largest problems for desert-dwelling animals is conserving water. Gerbils conserve water by producing concentrated urine and feces which allows metabolic water to remain in the animal's system. Due to the physiology of its kidney, G. setzeri is able to produce more concentrated urine than any other Gerbillurus species.

(Dempster et. al. 1998)

Contributors

Rebecca Anderson (author), University of Michigan-Ann Arbor, Phil Myers (editor), Museum of Zoology, University of Michigan-Ann Arbor.

Glossary

Ethiopian

living in sub-Saharan Africa (south of 30 degrees north) and Madagascar.

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.

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

References

Dempster, E., R. Dempster, M. Perrin. 1992. A Comparative Study of the Behaviour of Six Taxa of Male and Female Gerbils (Rodentia) in Intra- and Interspecific Encounters. Ethology, 91: 25-45.

Dempster, E., M. Perrin, C. Downs, M. Griffin. 1998. Mammalian Species Gerbillurus setzeri. American Society of Mammalogists, No. 598: 1-4.

Downs, C., M. Perrin. 1989. An Investigatin of the Macro- and Micro-environments of Four Gerbillurus Species. Cimbebasia, 11: 41-54.

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

Nowak, R. 1999. Walker's Mammals of the World. Baltimore and London: The Johns Hopkins University Press.

Wilson, D., D. Reeder. 1993. Mammal Species of the World. Washington and London: Smithsonian Institution Press.