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Jaculus blanfordiBlanford's jerboa(Also: Turkmen jerboa)

By Sheda Morshed

Geographic Range

Jaculus blanfordi occur in the southern and eastern desert plains of Iran, southern and western Afghanistan, and western Pakistan (Wilson and Reeder, 1992). They inhabit arid regions where extensive sand dunes are interspersed with gravel plains.

Habitat

These jerboas inhabit very arid rocky basins and areas of extensive rolling or flat sand dunes interspersed with gravel plains. They have also been reported from the shores of the Persian Gulf near Bushehr.

Physical Description

Like all jerboas, Jaculus blanfordi are saltatorial animals that have specialized adapatations for their desert environments. All jerboas have elongated hind-limbs that are about four times as long as their forelimbs. The short forelimbs are positioned close to the head and used for gathering food and burrowing. Locomotion is performed using the hind-feet and the posterior end of their long tails (Kirmiz, 1962).

A unique adaptation of members of this genus is the fusion of the metatarsal bones into one "cannon bone" as well as the loss of the first and fifth toes on each hind foot. Undersides of the three remaining long and laterally compressed toes are covered with thick, stiff hairs. The combination of these features improves traction and provides powerful leverage, so it's not surprising that members of this genus can jump to heights of nearly 2.25 m when escaping predators (Roberts, 1997).

The pelage is thick, comprised of thin and soft hairs that are dorsally cream-colored but blending with white ventral hairs along the sides of the body. The eye-lashes and long sensory hairs are gray or black, and the whiskers are white (Kirmiz,1962). The thick and compressed toe hairs are white near the skin and dark brown on the outer edges. The tail tuft is divided black anteriorly and white posteriorly. They have large, round eyes that are set close to the ears, ovally elongated ears that are relatively small compared to other dipodids, and a fold of skin which can be pulled over the nose while burrowing.

Reproduction

Very little is known about the reproductive cycle of this species. Based on data from other members of the genus and from a few available collected specimens of Jaculus blanfordi, the gestation period is believed to be approximately forty days long. One to three litters are born each year (Ziaie, 1996) and litters generally consist of three to four altricial young (Roberts, 1997).

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

Behavior

Jaculus blanfordi are non-colonial, nocturnal rodents that spend their days sleeping and nights foraging. They build intricate burrows by beating and shaping the sand with their blunt heads and muscular noses, forming tunnels between 1.5-2.5 meters long (Kimruz, 1962). The burrows are characterized by one entrance and several exits. If a mound of soil is visible from above-ground, it is an indication of an emergency exit that the individual sometimes forms by lightly packing a hole and leaving it closed until an emergency arises (Ziaie, 1996). There are no food storages or excrements kept inside the burrows, but camel fur or other soft materials may be used to line the dens during the winter months (Ziaie, 1996). During the summer months, the openings are sealed with approximately 50cm of soil, an act that bedouins believe is to prevent snakes or warm air from penetrating into the burrow (Kimruz, 1962).

At night Jaculus blanfordi forage independently, sometimes over distances of several miles. Individual burrow systems are in close proximity to each other and, on numerous instances, individuals have been found sleeping in the same burrow during the day. Further studies are needed to determine the social systems of this species.

Other species of this genus have been reported to hibernate in extreme temperatures. Although this behavior has not been studied in this species, Jaculus blanfordi in Iran have been observed to be actively foraging above ground late in December with temperatures below freezing. Daily cycles of complete torpidity in colder winter months have also been observed in captive individuals (Roberts, 1997).

Communication and Perception

Food Habits

The diet consists mainly of leaves and sprouting vegetation in wet seasons and of succulent roots, seeds and grains when rainfall is low or in the summer.

Economic Importance for Humans: Positive

No evidence yet to suggest their importance.

Economic Importance for Humans: Negative

None reported.

Conservation Status

Contributors

Sheda Morshed (author), University of California, Berkeley, James Patton (editor), University of California, Berkeley.

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.

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

Kirmiz, J. 1962. Adaptation to Desert Environment-A Study on the Jerboa, Rat and Man. London: Butterworths.

Lay, D. 1967. A Study of the Mammals of Iran Resulting from the Street Expedition of 1962-63. Chicago, U.S.A.: Field Museum of Natural History.

Nowak, R., J. Paradiso. 1999. Walker's Mammals of the World, 6th ed.. Baltimore and London: Johns Hopkins University Press.

Roberts, T. 1997. The Mammals of Pakistan. Pakistan: Oxford University Press.

Wilson, D., D. Reeder. 1992. Mammal Species of the World-A Taxonomic and Geographic Reference. Washington & London: Smithsonian Institution Press.

Ziaie, H. 1996. A Field Guide to the Mammals of Iran. Tehran: Department of the Environment of Iran.

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