1. Description

The fat-tailed gerbil is a medium-sized gerbil. Its body length is about 10 cm (4”), with a tail length of about 5 cm (2”). This gerbil has a thick, soft, fluffy coat. The hair at the back and the head is yellow-coloured, with a dark grey basis and a small black tip. The belly is clear white. Fat-tailed gerbils weigh about 40 grams. Their body is round and somewhat flattened. They have no clear neck and a very sharp face, with large oval-shaped black eyes. The ears of this species are low positioned, which gives this species a fox-like head. The legs are comparatively short for a gerbil. They look similar to a hamster, but unlike a hamster they have a pointed snout and a fat, almost bald, club-shaped tail from which they gets their common name of 'fat-tailed gerbil'. The fat-tailed gerbil stores fat in its tail, in the same way that the camel stores fat in its hump. Therefore, a healthy fat-tailed gerbil should have a nicely rounded tail. It is this tail which makes them easy to distinguish from all other gerbil species.

2. Lifespan

Captive specimens of the fat-tailed gerbil have an average life span of between 5 and 7 years https://animaldiversity.org/accounts/Pachyuromys_duprasi/ . In the wild, they are unlikely to reach this age.

3. Origin

The French zoologist Fernand Lataste discovered Pachyuromys duprasi in 1880 in Laghouat, Algeria. He was the first to describe the animal in detail in Le Naturaliste.

Fat-tailed gerbils are originally found in the Northern Sahara (North-western Egypt, Libya, Tunisia, and Algeria). There they live in sparsely vegetated sand sheets or rocky deserts. In the wild, fat-tailed gerbils live in simple burrows about one meter deep, in hard sandy soil. They may also occupy other species’ burrows.

4. Food

Fat-tailed gerbils are, as their pointed snout would suggest, mostly insectivorous in the wild, but will eat also a variety of plants. In captivity, they are kept on normal basic rodent mix, used to feed Mongolian gerbils or hamsters. They are particularly fond of mealworms, crickets, moths, and almost any other insect, even beetles. They can also be given some vegetables and fruit, like carrots, cauliflower, chicory, and apples. Because fat-tailed gerbils originated in dry areas and are not used to food which has high moisture content, they can get diarrhea after eating too much fruit and vegetable matter. Branches and twigs are rich in vitamins and very suitable besides their basic food, especially in winter. It is also good for their teeth, because they keep growing their whole life and by gnawing they keep their incisors at the right length. Hay is also very good for fat-tailed gerbils, because of its high fibre content.

5. Housing

The best way to keep fat-tailed gerbils is in a tank (aquarium or terrarium). It should measure at least 100 by 50 centimetres (39 by 20 in) for one or two gerbils. Fat-tailed gerbils are fond of digging, so it is important to provide them with a thick layer of bedding. Wood shavings can be used, but not pine or red cedar wood shavings; many rodents can react allergically to them, and may develop respiratory problems. Aspen wood shavings are considered to be the best.. They also need to take a sand bath regularly to prevent their fur from becoming greasy. Fat-tailed gerbils will make a nest; this may be underground in their burrow, on the surface in the bedding, or in a nesting box. Fat-tailed gerbils can be kept occupied by giving them gerbil toys, for example an exercise wheel. Keeping a breeding pair can be somewhat difficult. It is possible to keep fat-tailed gerbils singly, like Syrian hamsters.

6. Behavior

Fat-tailed gerbils are sociable animals, and sometimes live in colonies, but can also live solitary (alone). In the wild fat-tailed gerbils become active at dusk. In captivity fat-tailed gerbils seem to be diurnal. This gerbil species is active for some very short periods in between longer periods of sleep, and they are very deep sleepers. They sometimes go into a state similar to hibernation, but not true hibernation. Fat-tailed gerbils are very docile and almost never bite. People say even that wild fat-tailed gerbils that are trapped can even be handled right away without being bitten. They seem to lack the curiosity of the Mongolian gerbil, and behave more like a Syrian hamster than a gerbil. Fat-tailed gerbils spend a lot of time grooming their fur and washing their face. They like to dig a lot and take sand baths. They also enjoy running on exercise wheels.

When they fight, they shriek loudly and bite each other's tails.^[1] The mating ritual of the fat-tailed gerbil may also be confused with fighting.

Male fat-tailed gerbils, like most other rodents, have scent glands on their stomach and engage in marking their territory by stretching out and rubbing their bellies on the ground and furnishings. Their scent markings don't seem to be discernible to people and there is no noticeable odour from their cage unlike hamsters or mice.

7. Breeding

Fat-tailed gerbils are sexually mature when they are 2 months old, and in captivity they reproduce the whole year round. The gestation period of the fat-tailed gerbil is 19 days. Their average litter size is 3 to 6, and the pups are weaned at 3–4 weeks.

Breeding fat-tailed gerbils in captivity can be hard, as the females can be very aggressive when they are pregnant or nursing pups. They will attack the male, and even kill her mate if he is not housed separately after mating has taken place. The chance of a female housed with a male becoming pregnant is much less than it is with Mongolian gerbils. A proven method to breed fat-tailed gerbils is putting a male and a female together in a rather small tank with nothing else in it than some bedding material. No nesting box, nothing to play with, no food dish. This way there is really nothing the animals can fight about. They can't become territorial because of the small space and because there are no points to use as demarcation. With this method it is needed to keep the male and female together for one week and then separate them and put them in a nice big tank with all kind of furnishings, most likely the female is already pregnant.

The mating ritual of the fat-tailed gerbil is rather unusual. Both males and females stand on their hind legs and wrestle, squeaking. They never seem to actually bite each other, but they get rather rowdy. If the female is not receptive and the male doesn't give up, the female will turn and kick bedding at the male. The female will make a nest and get a little nippy when she will be ready to have her litter. They are good mothers.

8. Sexing

The difference between a male and a female fat-tailed gerbil is the same as with other small rodents. This difference can be seen at the distance between the urinary and anal openings. The distance between these openings in male fat-tailed gerbils is much larger than it is in females. Adult males have a large bulge at the base of the tail that is their scrotum. So their testicles are clearly visible. This is totally absent from females. When the pups have an age of about 2 weeks the hairs on the belly start to grow and bald spots can be seen on the belly of the females. These are her nipples. These bald spots are absent in males.

9. Colour Mutations

It appears that in Japan and other places either a grey (g) or chinchilla (cch) mutation has appeared. This fat-tailed gerbil is greyer in colour. But not everyone is sure that it is a colour mutation. It is also possible that these grey fat-tailed gerbils are from the Egyptian subspecies Pachyuromys duprasi natronensis. The juvenile coat of these gerbils is very grey but faded with age to a much more sandy colour. Some hybrids of the Egyptian and the Algerian subspecies have this grey coat as well, although it does lighten with age but is still greyish. Nothing else is known at this time.

10. Purchase

Duprasi are very new to the pet market, so they are not available on many places. In some countries they are not available; in others they are rare (Germany, France, Denmark and the UK), and in some countries, like the Netherlands, they are quite common. Occasionally, they can be found in a pet shop, but most don't have them.

11. Ailments

A healthy fat-tailed gerbil has bright eyes, is lively, and has a soft coat. They are dry and clean. Sick fat-tailed gerbils get lethargic and are not lively. Preventing illnesses is usually more effective than curing, especially for the fat-tailed gerbil; curing them is usually difficult. Fat-tailed gerbils are so small that even vets do not always know how they must treat the animal. Catching a cold can be fatal, although the biggest threats for a fat-tailed gerbil are draught and moisture. Hyperthermia, improper diet, and stress can lead to health problems. Not much is known about diseases of fat-tailed gerbils, because this small rodent has not been kept as a pet that long and often. But small rodents have generally the same ailments. An ailment that relatively often can be seen in fat-tailed gerbils are bite wounds at their tail, because fighting fat-tailed gerbils try to bite in each other's thick tail.