The Fat tail Gerbil ~ Pachyuromys Duprasis

Contents

Introduction

Duprasi are relative newcomers to the gerbil fancy, and have received many differing and often confusing reports on their behaviour and care. Some articles and internet sites describe them as nippy; whereas others describe them as docile and affectionate, and some reports describe them as being difficult to breed yet others say they are no more difficult to breed than a regular Mongolian gerbil. They are viewed by some as some sort of missing link between gerbils and hamsters so depending on your views on hamsters, i.e., if you're not a hamster type person, you may find them disappointing. Although not closely related to the Mongolian gerbil, it is a member of the gerbil family, Gerbillinae.

In their natural habitats duprasi populations are distributed from the Northeast of Egypt, Libya, Tunisia and Algeria, and share their habitat with several gerbil and jerboa species, including Meriones crassus ( Sundevalls jird), Gerbillus gerbillus ( Lesser Egyptian gerbil), Gerbillus andersoni (Anderson's gerbil ) Gerbillus perpallidus ( Pallid gerbil ), Gerbillus pyramidum (Greater Egyptian gerbil ) and Jaculus jaculus ( Lesser Egyptian jerboa )

Their habitat is desert, and can range from vast areas of sand with little vegetation, to rocky desert. Some specimens found in NW Cairo were dug out of totally barren gravel, however duprasi are much more abundant on the coastal plains where conditions are more favourable.

Typical vegetation found in these climates which help to form part of their staple diet are Anabis articulata, Artemisia monosperma, and Hyoscyamus muticus. They are found often occupying simple burrows, some being approx a metre in length, however the Algerian subspecies has been reported to be capable of digging complex burrow systems, but being an opportunist and leading a nomadic existence they can often be found occupying burrows of other species too. Most field research indicates they live a solitary existence or in small groups (most likely a female with offspring)

The Duprasi is designed to deal with adversity in its habitat and comes equipped with a club like, sparsely haired tail that is able to store excess fat and water, similar to the hump of a Camel. It makes use of most available foodstuffs and its pointed snout indicates that the Duprasi is insectivorous in nature.

The Duprasi in its natural habitat makes use of most food sources. There is anecdotal evidence that in Libya the Duprasi also feed on terrestrial snails, and field studies in Egypt have also found evidence of gnawed snail shells in the Western Desert. However it was unconfirmed that Duprasi were responsible.

As mentioned earlier the Duprasi digs quite considerably and its claws are well built for this task. The underside of the paws, are partially furred and this helps provide increased surface area for walking on shifting sands and also it provides an important buffer zone between the soles of it's feet and the hot desert sand. Also the white belly is an important adaptive feature which helps the animal thermoregulate itself.

Description of Duprasi Gerbils

The Duprasi is a small to medium sized gerbil that is usually between 3 - 5 inches in length, excluding the tail. The tail itself is usually approx. 2 inches in length, and is sparsely haired, flesh pink in colouration, and club shaped in appearance. Depending on the type of animals examined, their weights can vary tremendously and are between 30gms to 90 gms. It is interesting to note that the Refinetti Circadian Rhythm Laboratories, where they have mainly been used for experiments on heat production, the average weights of their lab specimens are 90 gms, and one 113gm male was reported in their studies. Their body is round and flattened, with no visible neck and relatively short legs. It has a triangular, sharp shaped face, with large oval black eyes. Their fur is extremely soft and is very pleasant to touch, and coat colours can vary from apricot, to grey, through to a buff brown. The belly is clear white, and nails are light coloured.

Behaviour of Fat-tailed Gerbils

The actual behaviour can be somewhat variable in nature, and a lot can depend on which subspecies, or indeed bloodline that is kept. (A large proportion of English stock initially had aggressive traits). However with good selection during breeding and also if handled at early stages most individuals will respond and will become very docile and affectionate animals given enough time. Many UK breeders have reported that the smaller Egyptian form is very aggressive and can be quite nippy to owners, especially the females, and that to try to keep them in groups, either male, female or mixed has on most occasions resulted in catastrophe. I keep and breed subspecies natronensis myself and through selection, animals can be achieved with a very favourable disposition, although in general they are a fairly active Duprasi and particularly like to make use of a wheel in their tanks. Some of the hybrid populations have favourable dispositions also, but in general most duprasi are aggressive amongst themselves and for those reasons, I prefer to keep mine in separate accommodation unless used for breeding.

Duprasi are diurnal but can spend a lot of the day asleep interspersed with short periods of activity, and some look very comical sleeping on their backs with their feet pointing skywards! In what is obviously a very deep sleep. They become most active at dusk, but a wheel or indeed other toys in their environment usually makes them twice as active, prevents boredom, and reduces stereotypical behaviour.

Duprasi also possess scent glands and in large aquaria can be observed rubbing their bellies on different items and also on the tanks base, to mark their territory.

Occasionally there are reported cases of cannibalism, and is usually a mother eating her young. This can be either due to stress, usually if the male has been left in after the female has given birth, or simply if she's a young first time mother, she may cull or partially cull her litter, if she feels she cannot cope, and is struggling to raise them.

Duprasi suffer from no particular health problems and are a rather robust species that can live from 2 - 5 years.

Breeding Fat-tailed Gerbils

The Duprasi section of my rodentry although simple in design has yielded some excellent results. All my Duprasi are kept solitary, and are placed together only for the purpose of breeding. The male is either removed from his breeding tank after a successful mating has been observed or removed on the day of the litter. After this period the male goes into a convalescence/ recuperative tank until it's in good condition to breed again. A similar procedure is used for the female. If a successful mating has been observed she can be placed in one of the convalescence tanks to have the litter, or if the male is removed on the day of the litter she can be left in the breeding quarters. If left undisturbed and unstressed she will successfully raise the litter. When the litter has opened its eyes, it is wise to move mum and litter to one of the larger convalescence tanks. Daily interaction with the pups is recommended at this stage, to get them used to you and the smell of humans and also this then enables you to select the duprasi with the best temperament and good type for further breeding.

The above methods have several advantages from a breeding and husbandry standpoint;

  • It minimises any possible or prolonged acts of aggression
  • The female can become very aggressive when pregnant or nursing a litter, and Duprasi kept in traditional pairs or trios, always exhibit permanently scarred tails, the males usually come off worse, and I've viewed several males in different collections completely minus a tail!
  • This method allows both sexes controlled, adequate resting periods between matings and litters, and overbreeding, with its associated health problems are minimised. Although it's been said in many articles that Duprasi can breed all year round, it's wise not to, and allow only 2 - 4 litters in their lives for the females. It can easily be observed in nursing females, that the tail seems to deflate, shrivel and lose weight, which indicates that a vast amount of resources are being used to raise the litter, (see diet). After raising and weaning her pups, the female with correct diet and enough rest, will soon recuperate and be in good breeding condition once again.
  • Stud males should similarly be given a resting period between matings. This promotes a healthy animal and reduces overbreeding problems.

The tail itself is an overall indicator of health and should be plump and supple. In fact the tail is an important point to consider when purchasing stock of Duprasi. It should be fat or plump and free of any marks or blemishes, a shrivelled tail may indicate the animal is in poor health or an old specimen. This is important, as breeding stock of Duprasi should be relatively young, especially in the case of females. To obtain a successful breeding female she has to be mated within 6 months. If they are not pregnant before this period its unlikely she ever will.

From a breeder's standpoint, a simple line - breeding and/or backcross regimen from a few stud males is a much safer option than simply inbreeding the pups from the litters. Also when new bloodlines are introduced, their health and temperament traits can be accurately monitored as they interact with your own bloodlines.

When introducing animals for the purpose of mating, always introduce the female to the male in his own breeding quarters. You should also familiarise yourself with their usual mating ritual. Soon after introduction the male will quickly gain interest, pursue the female, and attempt to sniff her underside from all angles, usually to the squeaking protestations of the female. Sometimes the female may retaliate and get aggressive during the introduction, especially if the male is very persistent in his attempts to mate. Often the chasing and squeaking leads to boxing, which involves them standing up on hind legs, whilst sparring with their forepaws, imitating a little boxing match, which is usually accompanied with loud squeaking. Careful observation of the pair in the hours and days that follow will allow you to control any adverse situation that may arise. Sometimes the female may not accept the male; this situation will rarely happen though if a young female is introduced to an older stud male of known fertility. If you do observe any blood or obvious injuries during introduction, separate them immediately, however do expect the wrestling, boxing, and chasing, as all this is probably a part of their mating ritual.

Gestation periods for Duprasi are between 19 - 23 days, the pups are born naked, blind, deaf and helpless. Litter sizes can vary from 2 - 9. The pups will become sexually mature at approx 2 months of age.

Duprasi Gerbil's Diet

Duprasi do very well on normal gerbil/hamster mix, with the addition of alfalfa pellets (unmollassed). Fresh water should always be provided. Being insectivorous in nature live foods and or chopped meat can also be given as an occasional supplementation. If you so desired dry cat food or dog biscuits could be used instead of live food as a supplemental for extra protein. In addition to this, once or twice a week the diet can be further supplemented with a slice of fresh fruit or vegetables, favourites I find are, Cauliflower, Chicory, Baby leaf spinach, Cauliflower, Savoy cabbage, Curly Kale, Carrot, Broccoli, Sweet potato, Grapes, Apple, Pomegranate (when available), and Fennel.

Remember any fresh food that is uneaten should be removed after an hour or so to minimise the spread of bacteria and prevent fouling of the tank. When breeding it helps if you increase the protein ration in their food mix, also bread soaked in condensed milk is a good supplement for nursing mothers. The extra nutrients and calories come in very handy in maintaining health during this period. A salt lick or Cuttlefish bone should also be provided.

Housing for Duprasi Gerbils

General housing for duprasi as pets should 24 - 30 inch aquaria. This can then be fully furnished and include several cardboard tubes or empty glass jars to simulate burrows and nest chamber. Carpet roll tubes are very useful, but have to be sawed into convenient lengths but are considerably much more resistant to gnawing. This can then be covered with a thick layer of substrate, good quality shavings are fine to use, and this is mainly due to the fact that they are keen burrowers!

A wheel is appreciated and helps to keep the animal in tiptop condition, and prevents boredom. Chinchilla sand baths will also be appreciated and will help prevent the coat from becoming too greasy. This can be either introduced once a week under supervision or placed in permanently but well out of the reach of the substrate, otherwise it would soon be buried. Plain toilet tissue is used for bedding.

Breeding quarters

At present I use 12 inch by 15 inch by 5 inch high plastic containers for the introduction of breeding pairs. I do not recommend trios. I prefer this set up to small aquaria as the opaque sides let in light but allow the animals privacy, which reduces stress; this isn't possible in aquaria unless you painted the sides of the tank.

There should be no furnishings at all, only substrate, bedding and food, which is best just placed on the bedding. This leaves the animal with very little to fight about, as in such confined conditions they will be unable to mark out any territories.

Several tanks can be used for this purpose, depending on the amount of animals that you have in your breeding programme. They should ideally be 24 - 30 inch and be fully furnished. They are also ideal for sick or convalescing animals.

Subspecies, Hybrids and Mutations

Pachyuromys duprasi (Algeria)

Pachyuromys duprasi was discovered in 1880 in Laghouat, Algeria, by French zoologist, Fernand Lataste, who first describes the animal in detail in Le Naturaliste.To my knowledge there exists 2 other subspecies, duprasi natronensis from North Egypt, and also duprasi faroulti (Thomas 1920), from West Algeria. However some authors regard the West Algerian subspecies as a synonym for Pachyuromys duprasi.

Duprasi were first introduced to private collections in the UK about 1995. The Duprasi that were first encountered were relatively large, exceptionally docile, and quite hamster like in nature, their coats were apricot to sandy, and their tails were large and fat it was these early specimens that earned the nickname " Beer mat " Gerbils in the U.K. , because of their somewhat round and flattish appearance. The first imports proved difficult to breed and were most probably Algerian in origin. Roughly 4 - 6 years ago a smaller type appeared in some collections. It was smaller and appeared much greyer in appearance, and was at first thought to be possibly a grey mutation, however it was later found out that the greyish coat in the juvenile stage later fades to a sandy colouring with grey undercoat on most individuals. This effect can be variable and some adult specimens can remain quite grey or buff brown in colour. It later turned out through research that the provenance of these later imports was Egypt. The specimens I first encountered were feisty, especially the females. They appeared to be much more curious and a lot more active than the original imports, and in general behaviour was quite dissimilar. They appeared a much easier subject to breed.

Certain UK keepers who were initially unaware of differing subspecies, and who had a few descendants left of the original Algerian imports, quickly took on stock of natronensis and paired these to their remaining Algerian stock. The resulting f1 hybrids were then most likely either inbred or backcrossed inadvertently to other natronensis specimens, which were now becoming more available in the UK. Various forms of this initial hybrid exist, in coat colour they can vary from a very sandy/ apricot, to grey, to buff brown. All are smaller than the original Algerian imports, and also the tail doesn't look as fat or club like, but shorter and similar in size and shape to natronensis. Most are quite docile in nature, and compared to original imports, are relatively easier to breed. Most of the variations in coat colour are probably the result of modifying genes and are not mutations.

It's ironic to note that the actual breeders chiefly responsible for the initial f1 cross and subsequent distribution of this hybrid throughout the UK are supposedly staunch anti-hybrid breeders, and publicly promote an anti-mutation stance in regard to breeding species. Initially I was unconcerned, and thought that inevitably this would occur, but recently a lot of hybrids have started to hit the showbench at some NGS shows, and a lot of people are unaware when they use these animals for further breeding programmes.

The grey mutation, if it still exists, (Most likely a chinchilla mutation or other greying locus responsible) was first reported from a Japanese source on the NGS website, but I could find no further information on this particular mutation.

Article by Eddie Cope

Gallery

Photo Credits

Many thanks to Heather Carol (Lyddiecleave burrow) for pics 6-11

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