Jaculus jaculuslesser Egyptian jerboa

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Geographic Range

Jaculus jaculus can be found in central Asia, North Africa and Arabia in countries such as Sudan, Israel, and Morocco. The species is especially common in Egypt, where it gets its common name, Lesser Egyptian Jerboa. (Brown ET AL., 1994; "Walker's Mammals of the World", 1997)

Habitat

Jaculus jaculus lives in desert and semi-desert areas that can be sandy or stony. They can also be found in less numbers in rocky valleys and meadows. ("Walker's Mammals of the World", 1997)

Physical Description

Jaculus jaculus is the smallest species in the genus Jaculus. It is very small with a darkish back and lighter colored underbelly. There is also a light-colored stripe across its hip. Jerboas are a lot like a tiny kangaroo in locomotion and posture. The hind feet are incredibly large, 50 to 75 mm, and used for jumping. Each hind foot has three toes. The tail is very long, 128 to 250 mm, with a clump of hairs at the tip which is used for balance. It has moderately large eyes and ears. Females are larger than males. ("BBC - Nature Wildfacts", 2002; "Walker's Mammals of the World", 1997)

  • Sexual Dimorphism
  • female larger
  • Range mass
    43 to 73 g
    1.52 to 2.57 oz
  • Average mass
    55 g
    1.94 oz
  • Range length
    95 to 110 mm
    3.74 to 4.33 in
  • Average length
    100 mm
    3.94 in
  • Average basal metabolic rate
    0.515 W
    AnAge

Reproduction

Not much is known about the mating system of J. jaculus because they are solitary and nocturnal. However, it appears as though a male will mate with any number of females he comes across, while a female will mate with only one male.

A male jerboa attracts a mate by standing on his hind legs in front of a female. When the female approaches, he faces her and slaps her at regular intervals with his short front limbs. Lesser Egyptian jerboas breed at least twice yearly, and every three months in captivity. Breeding occurs from June to July and from October to December. Females have an average of 3 young per litter. Young reach independence at 8 to 10 weeks, and become sexually mature at 8 to 12 months. ("BBC - Nature Wildfacts", 2002; Happold, 1967)

  • Breeding interval
    Lesser Egyptian jerboas breed at least twice yearly, and every three months in captivity.
  • Breeding season
    Breeding occurs from June to July and from October to December.
  • Range number of offspring
    1 to 6
  • Average number of offspring
    3
  • Average number of offspring
    3
    AnAge
  • Average gestation period
    25 days
  • Average gestation period
    45 days
    AnAge
  • Average weaning age
    6 weeks
  • Range time to independence
    8 (low) weeks
  • Average time to independence
    10 weeks
  • Range age at sexual or reproductive maturity (female)
    8 to 12 months
  • Average age at sexual or reproductive maturity (male)
    Sex: male
    137 days
    AnAge

Jaculus jaculus bred in captivity do not survive. The mother will not touch the pups after they are born. In one case, the mother kicked the babies out of the nest. In the wild, however, the babies and the female are brought into close contact in the burrow. At birth, the pups are hairless and tiny with a head and body around 25 mm, tail around 16 mm. They weigh about 2 g and their hind feet are much shorter in proportion to adults at around 9 mm. Their eyes are closed over, but they can crawl around using their front limbs. The young will not leave the burrow until they are able to be self-sufficient at around 8 weeks of age. (Happold, 1967)

  • Parental Investment
  • altricial
  • pre-hatching/birth
    • provisioning
      • female
    • protecting
      • female
  • pre-weaning/fledging
    • provisioning
      • female
  • pre-independence
    • provisioning
      • female

Lifespan/Longevity

Jaculus jaculus cannot be bred in captivity due to lack of maternal care. However, captured young jerboas have been successfully tamed and kept as pets. These tame jerboas can live up to 6 years. The oldest jerboa found in the wild was 4 years old. ("BBC - Nature Wildfacts", 2002; "UAE INTERACT", 2000; Happold, 1967)

  • Range lifespan
    Status: wild
    3 to 4 years
  • Range lifespan
    Status: captivity
    5 to 6.4 years
  • Typical lifespan
    Status: wild
    2 to 3 years

Behavior

Jaculus jaculus moves around only at night when it is cooler in the desert. They are solitary creatures that dig burrows in the sand in a counterclockwise spiral. The burrows are dug in hard ground and go to a depth of around 1.2 meters. There are a couple of additional exits off of the main burrow, and the nest is at the very bottom. Jerboas move by hopping along the terrain with their huge hind legs. One leap can be several meters in length. They have a molting season from March to July. An interesting thing about these animals is their activity of sandbathing. They make a shallow hollow in the sand by digging it out, then lay in it and rub their bodies along the sides. During hot spells and dry periods, J. jaculus aestivates in its burrow. It has been debated that J. jaculus hibernates in the winter, but only a few individuals have been known to do so. ("UAE INTERACT", 2000; Happold, 1967; "Walker's Mammals of the World", 1997)

  • Range territory size
    10 to 14 km^2

Home Range

Jerboas leave their burrow after sundown and can travel long distances, about 10 km, away from it in search of food. They can cover a lot of ground quickly because of their huge feet and hopping stride. ("Walker's Mammals of the World", 1997)

Communication and Perception

Because J. jaculus is solitary, not much is known about how individuals communicate with one another. Animals in captivity seem to recognize each other by smell. They close their eyes and come together until thier noses touch and keep contact for 1 to 5 seconds in this way. (Happold, 1967)

Food Habits

Although lesser Egyptian jerboas lives in the desert, they do not drink, depending on the greens and insects that they eat to provide enough water and moisture. Their diet consists of roots, grass, seeds, grains, with some insects. (Happold, 1967; "Walker's Mammals of the World", 1997)

  • Animal Foods
  • insects
  • Plant Foods
  • roots and tubers
  • seeds, grains, and nuts

Predation

Jaculus jaculus is very fast when hopping and escape seems to be its defense against predators. Individuals often run down into their burrows to get away as well. They do not bite often when handled, so they do not have any real means of defense against predators when caught. The predators of this species are desert carnivores including pallid foxes (Vulpes pallida), Nile foxes (Vulpes vulpes), striped weasels (Ictonyx striatus), saw-scaled vipers (Echis carinatus), and moila snakes (Malpolon moilensis). Some humans eat jerboas as well. (Happold, 1967)

Ecosystem Roles

Jaculus jaculus as prey provides nourishment and water to other animals in the desert. It helps to disperse seeds in the desert. A vacated jerboa burrow could become home to spiders and scorpions. Jerboas are also homes themselves for numerous kinds of parasites such as ticks, fleas, mites, lice. (Happold, 1967)

  • Ecosystem Impact
  • disperses seeds
  • creates habitat

Economic Importance for Humans: Positive

Some humans eat jerboas for food. Jerboas are becoming popular pets because they are easily tameable and do not commonly bite. (Happold, 1967)

Economic Importance for Humans: Negative

There are no known adverse affects of J. jaculus on humans.

Conservation Status

As of right now, this species is not on any conservation lists.

Contributors

Matthew Wund (editor), University of Michigan-Ann Arbor.

Theresa Keeley (author), University of Michigan-Ann Arbor, Phil Myers (editor, instructor), Museum of Zoology, University of Michigan-Ann Arbor.

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.

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.

fertilization

union of egg and spermatozoan

food

A substance that provides both nutrients and energy to a living thing.

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.

heterothermic

having a body temperature that fluctuates with that of the immediate environment; having no mechanism or a poorly developed mechanism for regulating internal body temperature.

hibernation

the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.

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.

polygynous

having more than one female as a mate at one time

saltatorial

specialized for leaping or bounding locomotion; jumps or hops.

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

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

2002. "BBC - Nature Wildfacts" (On-line). Accessed February 10, 2004 at http://www.bbc.co.uk/nature/wildfacts/factfiles/620.shtml.

2000. "UAE INTERACT" (On-line). Accessed February 10, 2004 at http://uaeinteract.com/nature/mammal/mam17.asp.

The Johns Hopkins University Press. 1997. "Walker's Mammals of the World" (On-line). Accessed February 10, 2004 at http://www.press.jhu.edu/books/walkers_mammals_of_the_world/rodentia/rodentia.dipodidae.jaculus.html.

Brown ET AL., 1994. Coexistence of Negev Desert Rodents. Ecology, 75: 2290-2297.

Happold, D. 1967. Biology of jerboa, Jaculus jaculus butleri (Rodentia, Dipodidae), in the Sudan. Journal of Zoology, London, 151: 257-274.