Jerboa

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iJerboa Fossil range: Middle Miocene - Recent
Jaculus jaculus
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Rodentia Superfamily: Dipodoidea Family: Dipodidae Fischer de Waldheim, 1817
Genera
10 genera in 5 subfamilies

Jerboas are the members of the family Dipodidae; they are small jumping desert rodents of Asia and northern Africa that resemble mice with a long tufted tail and very long hind legs. The small forelegs are not used for locomotion. In general, Asiatic jerboas have five toes on their hind feet and African jerboas have three; the shapes of their ears vary widely between species. Jerboa fur is long, soft and silky. Diet varies considerably: some are specialist seed, insect, or plant eaters, others are omnivores.

The English word jerboa may have been derived from the similar sounding Arabic word jerbu'a (جربع) or the Hebrew word yarboa (יַרְבּוֹעַ) which denote this animal.

The ancestors of the modern jerboas probably separated from the more generalised rodents about 8 million years ago on the arid plains of Turkmenistan, Kazakhstan and Mongolia, and then spread to Europe and northern Africa. With the exception of Europe, where they died out, this remains their current range.

Their ability to hop is presumed to be an adaptation to help them escape from predators, and perhaps to assist with the longer journeys a desert-living animal must make to find food. It is interesting to note that although jerboas are not closely related to the hopping mice of Australia or the kangaroo rats of North America, all three groups have evolved a similar set of adaptations to life in the deep desert.

Jerboas are nocturnal. During the heat of the day, they shelter in burrows. They create four separate types of burrow: two temporary, and two permanent. The temporary burrows are plain tubes: those used to escape from predators during the night are just 10 to 20 cm deep, unsealed and not camouflaged; the temporary daytime burrows are well-hidden and sealed with a plug of sand to keep heat out and moisture in, and are 20 to 50 cm long.

Permanent burrows are also sealed and camouflaged, and often have multiple entrances. They are much more elaborate structures with a nesting chamber. The winter burrows have food storage chambers 40 to 70 cm below ground level, and a hibernation chamber an astonishing 1.5 to 2.5 metres down.

Perhaps the best-known species is the Lesser Egyptian Jerboa (Jaculus jaculus) which occupies some of the most hostile deserts on the planet. It does not drink at all, relying on its food to provide enough moisture for survival. Found in both the sandy and stony deserts of north Africa, Arabia and Iran, this small creature estivates (a form of hibernation) during the hottest summer months, and has the ability to leap a full metre to escape a predator.

Two species are considered threatened: the Five-toed Pygmy Jerboa and the Thick-tailed Pygmy Jerboa, which are both classified as vulnerable (VU). Many other species have been placed in a "lower risk" or category, and one species (Thomas's Pygmy Jerboa) lacks the data for assessment.

[edit] Classification

• ORDER RODENTIA
• Family Dipodidae
  • Subfamily Zapodinae: jumping mice, 4 species in 3 genera
  • Subfamily Sicistinae: birchmice
    • Sicista
      • Armenian Birch Mouse, Sicista armenica
      • Northern Birch Mouse, Sicista betulina
      • Caucasian Birch Mouse, Sicista caucasica
      • Long-tailed Birch Mouse, Sicista caudata
      • Chinese Birch Mouse, Sicista concolor
      • Kazbeg Birch Mouse, Sicista kazbegica
      • Kluchor Birch Mouse, Sicista kluchorica
      • Altai Birch Mouse, Sicista napaea
      • Gray Birch Mouse, Sicista pseudonapaea
      • Severtzov's Birch Mouse, Sicista severtzovi
      • Strand's Birch Mouse, Sicista strandi
      • Southern Birch Mouse, Sicista subtilis
      • Tien Shan Birch Mouse, Sicista tianshanica
  • Subfamily Cardiocraniinae
    • Cardiocranius
      • Five-toed Pygmy Jerboa, Cardiocranius paradoxus
    • Salpingotus
      • Thick-tailed Pygmy Jerboa, Salpingotus crassicauda
      • Heptner's Pygmy Jerboa, Salpingotus heptneri
      • Koslov's Pygmy Jerboa, Salpingotus kozlovi
      • Baluchistan Pygmy Jerboa, Salpingotus michaelis
      • Pallid Pygmy Jerboa, Salpingotus pallidus
      • Thomas' Pygmy Jerboa, Salpingotus thomasi
  • Subfamily Dipodinae
    • Dipus
      • Northern three-toed Jerboa, Dipus sagitta
    • Ermodipus
      • Lichtenstein's Jerboa, Eremodipus lichensteini
    • Jaculus (rodent)
      • Blanford's Jerboa, Jaculus blanfordi
      • Lesser Egyptian Jerboa, Jaculus jaculus
      • Greater Egyptian Jerboa, Jaculus orientalis
      • Turkmen Jerboa, Jaculus turcmenicus
    • Stylodipus
      • Andrew's Three-toed Jerboa, Stylodipus andrewsi
      • Mongolian Three-toed Jerboa, Stylodipus sungorus
      • Thick-tailed Three-toed Jerboa, Stylodipus telum
  • Subfamily Euchoreutinae
    • Euchoreutes
      • Long-eared Jerboa, Euchoreutes naso
  • Subfamily Allactaginae
    • Allactaga
      • Balikun Jerboa, Allactaga balikunica
      • Gobi Jerboa, Allactaga bullata
      • Small Five-toed Jerboa, Allactaga elater
      • Euphrates Jerboa, Allactaga euphratica
      • Iranian Jerboa, Allactaga firouzi
      • Hotson's Jerboa, Allactaga hotsoni
      • Great Jerboa, Allactaga major
      • Severtzov's Jerboa, Allactaga severtzovi
      • Mongolian Five-toed Jerboa, Allactaga sibirica
      • Four-toed Jerboa, Allactaga tetradactyla
      • Vinogradov's Jerboa, Allactaga vinogradovi
      • Bobrinski's Jerboa, Allactodipus bobrinskii
    • Pygeretmus
      • Lesser Fat-tailed Jerboa, Pygeretmus platyurus
      • Dwarf Fat-tailed Jerboa, Pygeretmus pumilo
      • Greater Fat-tailed Jerboa, Pygeretmus shitkovi
  • Subfamily Paradipodinae
    • Paradipus
      • Comb-toed Jerboa, Paradipus ctenodactylus