The upper parts are pale to dark sandy or buffy, the underparts are whitish, and there is a whitish stripe on the hip. Each hind foot has three toes, and there is a cushion or fringe of hairs under the toes. The eyes and ears are relatively large, the upper incisor teeth are grooved, and there are no premolars. Females have 8 nipples.
Jerboas are found in a variety of habitats, including both roling and relatively flat sandy deserts, saline deserts, rocky valleys and meadows. Their burrows are generally excavated in hard ground, are kept sealed during summer and left open in winter, slant to a depth of about 1-2 meters, and include a sleeping chamber with a nest of camel's hair or shredded vegetation, one or two escape tunnels, and in the case of J. orientalis a food storage chamber.
These jerboas progress along the ground with leaps that may measure several meters in length. Captives were observed to jump from a standing position to a height of almost a meter. When they are standing, the long tail is held curved and the tuft touches the ground, thus providing support.
Jaculus is exclusively nocturnal and may move over a considerable distance in a single night; the track of one individual was reportedly followed for 14 km.
Wet weather is thought to cause reduced activity, but there is conflicting information on winter dormancy. It is also apparent that Jaculus retires to its burrow and estivates during long, hot, dry periods.
The diet of Jaculus includes roots, sprouts, seeds, grains, and cultivated vegetables. Sufficient metabolic water is probably derived from vegetation, as captive animals have refused to drink for long periods, even though water was placed in their cages daily.
Jaculusorientalis is very sociable and live in small groups, whereas the J. jaculus is strictly solitary.
J. jaculus in captivity can give birth to litters of 3-4 young every 3 months. They have a gestation period of 25 days or less.
J. orientalis have a average litter size of 3 and a gestation period of about 40 days.
J. jaculus can live about 5-6 years in captivity.
In Europe mainly two Jaculus species are being kept as pets; Jaculus jaculus and Jaculus orientalis.
This species is very hard to breed, even zoo's rarely breed them. And if they breed the pups only survived for a few days. Lately some people did succeed in breeding J. jaculus.
Here a breeding report:
The animals are kept in an aquarium of 80 cm long with a wooden lid with mesh wire in the middle for fresh air.
The animals have a nest which look like a cave, made from tree roots. This cave has entrances at the top and sides. There is a stone on top of the cave, with a lamp shining on it, to heat the stone. The stone emits warmth into the cave which leads to a temperature above 20 degrees Celsius in the nest.
With a time clock the light is settled to have a good day- night rhythm. In the evening the light is switched off, to make the temperature decline.
The nesting material is hay and rough sheep wool. With this the Jerboas make a soft nest.
They need enough sand with which they can close the entrances of the cave completely.
They eat a mix of grains, salad, carrots, apples and germinated seeds.
After a gestation period of about 23 days, 1-4 pups are born. You can hear them squeak. The male can be left with the female and will also sleep in the nest. After about 4 weeks the pups leave the nest. They still have their eyes closed and crawl around. The mother keeps carrying them back to the nest. At about 5 weeks the eyes open and in the next 8-10 days they learn how to walk properly. At about 6 weeks they start to eat vegetables, seeds will be eaten later. At about 8-10 weeks the pups can leave the parents.
You can find more information about Jaculus jaculus here.
The great jerboa lives in northern Africa, mainly in coastal- and salt deserts, but also in sandy and rocky areas. This animal does look physiologic suitable for living in real dry deserts, but isn't. They live in semi-deserts because there is always enough food available. They also live in barley fields, cultivated by the Bedouins.
During mating the animals run after each other while jumping. Sometimes the female stops for a few moments and the mating takes place. This can go on for hours.
After a gestation period of 28 days the pups are born naked and helpless. After about 7 weeks the pups leave their nest.
Young J. orientalis
Great jerboas can reach an age of about 5 years.
The great jerboa is strictly nocturnal, they start being active during dusk.
They are very social animals, not aggressive towards humans or congeners. They are rarely kept in captivity where they are very tame and don't ever bite.
They always cover their nest so that the entrances are not visible.
When they are threatened the Jaculus orientalis throws sand in the opponents face with its front paws.
In nature these animals eats sprouted young plant parts, roots, seeds and grains.
Jaculus orientalis is hunted by snakes, desert foxes and small predators. Their black and white tail tuft is to distract the partially sighted snakes.
head/body: 135-160 mm
tail: 195-245 mm
hind feet: 70-80 mm
ear: 28-35 mm
weight: 110-145 grams
Off course these rather big animals need a lot of space!