The Zoologist/4th series, vol 5 (1901)/Issue 722/Notes on the Egyptian Jerboa (''Dipus jaculus'') in Captivity, Renshaw

by Graham Renshaw

 

NOTES ON THE EGYPTIAN JERBOA (DIPUS
JACULUS) IN CAPTIVITY.

By Graham Renshaw, M.B.

 

The immense number of species of animals which are now kept as pets almost defies enumeration, and it is difficult indeed to select for special notice any single animal; for all the others compete with it in claiming the attention of those zoologists to whom mammal or bird, reptile or fish, is more attractive in the living state than as a stuffed skin or mounted skeleton in a museum case. The furred and feathered captives of to-day range from the schoolboy's Rabbits and White Mice, Pigeons and Canaries, to the Burchell Zebras and White-tailed Gnus, the Kangaroos and Emus of wealthy acclimatisation societies; and half-way between these extremes one may place various "out-of-the-way" pets—by no means ordinary domestic animals, yet also by no means unobtainable—such small specimens as Armadillos, Agoutis, Phalangers, and Wallabies.

Amongst this assemblage of "out-of-the-way" pets is included a pretty little rodent rapidly and deservedly advancing in popularity—the Egyptian Jerboa (Dipus jaculus). Not only does its tiny form interest the scientific naturalist, with its quaint little body perched on an absurd pair of stilt-like legs whose disproportionate size contrasts strangely with the almost microscopic proportions of the fore limbs; but its beaming eye, vivacious manners, and odd bird-like gait (now running like a Rail, and now hopping like a Sparrow) endear it also to the general public. Having for some considerable time possessed examples of the Egyptian Jerboa, I have had many opportunities for studying their behaviour in captivity, and perhaps the collected results of the observations may interest others besides myself.

The Egyptian Jerboa measures about 14¾ in. from the snout to the tip of the tail, exclusive of the terminal tuft of hair. The colour varies somewhat: in large well-grown specimens it is sandy, but I have noticed that in small Jerboas it may have a distinct greyish tinge. The tail is brownish, tipped with black and white.

When standing "at ease" the Jerboa uses its tail as a kind of third leg, this tripod arrangement recalling similar habits practised by other mammals widely differing from the Jerboa—such as Kangaroos or Wallabies, and perhaps also the huge extinct Megatherium of South America. The Jerboa presses its tiny fore legs close to the chest, and the body projects forwards. When moving this little animal employs one of two gaits: (1) a quick run, each leg being moved alternately; and (2) a series of tremendous leaps, the long tail being held out straight behind, as if to counterbalance the forwardly directed head and body. I well remember a fine male, which I still possess, escaping from his prison, and the great rapidity with which he bounced along over a wide lawn, as if made of animated india-rubber, the tiny fugitive progressing at a lightning speed that rendered pursuit hopeless. His final recapture was effected by strategy.

Jerboas are usually stated to be nocturnal; so no doubt they are to a large extent, but by no means entirely so. They are at any rate also crepuscular, if not diurnal, my own animals being lively at all hours, retiring to rest irregularly for a longer or shorter interval. When asleep they repose either huddled up in a furry ball (head tucked in and tail coiled round them), or else lying on one side. The latter position was rather horrifying at first, suggesting that the Jerboa had departed this life; however, a dead Jerboa either lies flaccid with limbs extended, or else rolls over on its back, the long legs sticking up in the air. These animals are lethargic in wet and foggy weather, and sleep much later in the day than when it is dry and warm. On rousing up for the evening the Jerboa frequently opens its eyes, and remains motionless in a dozing semi-somnolent condition for perhaps half an hour or an hour before becoming fully active. It then begins to clean itself with great care, smoothing its fur, and paying special attention to the terminal tuft of the tail, the hair of which is absurdly parted down the middle in the neatest possible manner. The Jerboa also frequently stretches itself in the most amazing fashion, extending itself to the utmost, so that, as it lies on its side, the long hind legs form almost a straight line with the body. The next instant the little contortionist flexes its body, the long legs projecting in front of its muzzle as rigidly as a moment before they were extended backwards. Food is the next consideration: the Jerboa begins to run about with remarkable nimbleness and lightness, like some wee brown gnome or "brownie" (literally, a "brownie"), ever and again abruptly stopping to examine some object. Oats, corn, millet-seed—any dry food is welcomed, the grains of food being clasped in the tiny fore paws, and conveyed to the mouth in true rodent fashion. Green-stuff is also taken freely. Although probably, like the Giraffe, the Eland, and the Gemsbok, the Jerboa has often, in its own African deserts, to go without water for long periods, it drinks freely when it has the opportunity, and I have frequently seen my own animals drink, scooping up the water with the fore paws, and conveying it to the mouth so quickly that at first glance the animal seems to be lapping the water like a Dog.

Jerboas are very playful: if their cage is carpeted with sand, they will stretch themselves on it with great glee, and attempt to burrow in it, ploughing up the sand with their muzzles. They also have a mischievous habit of nibbling woodwork, and on one occasion a pair of these animals utterly ruined a small bird-cage given to them for a sleeping apartment by demolishing both floor and back, an enormous hole being gnawed in each. One Jerboa, indeed, which was recently addressed to me, I never got, for in transit the industrious prisoner nibbled his way out to freedom, doubtless to the astonishment of the railway officials. Twigs and branches with the bark on are quickly stripped bare; in this respect these rodents are fully as destructive as Budgerigars or Parrots. Jerboas climb well, running quickly up wire-netting, and jumping off recklessly on to the floor from a considerable height; I once lost a nice female from a compound fracture of the leg, supposed to have been caused by this habit. She persisted even after the limb was broken in scrambling up the wires on one leg, and did not die for at least a week after the injury, eating and sleeping well in the interval. Jerboas are very tough; the male I now possess once fell through a hole in the floor of a loft upon the concrete pavement of the room below, from a height sufficient to have seriously injured, if not killed, a human being. Nevertheless, though his muzzle was covered with blood when I picked him up, causing very laboured respiration for some time after, on revisiting him about three hours later he had already recovered, and was as active and lively as before. This is the more remarkable, as a female which was killed by accident died in three minutes, the skull cracking like an egg-shell, and the animal being convulsed all down one side.

Solitary Jerboas remain silent for weeks together, but a pair during courtship repeatedly utter a curious croaking noise, sitting facing each other with their depressed muzzles in contact. I have not yet succeeded in breeding these little animals. The above are the results of observations conducted during the past ten months on captive animals, well-fed and well-housed, with abundance of room for exercise, and good bedding. The list of specimens is as follows: —

(1) Adult female, purchased November, 1900.—At first lively and feeding well, this Jerboa soon became somnolent and stupid, probably owing to the continued damp weather, with almost total absence of sun. It uttered no sound, and was very gentle, never attempting to bite. This Jerboa died in the winter of 1900–1.

(2, 3) Adult male and female; a fine well-grown pair, purchased Jan. I4th, 1901.—The male (still living) was a remarkably fine animal, always more active and more easily roused than the female, who, I think, must have been an old animal, as her partner paid her little attention. The male was a public character, who achieved considerable notoriety; for, having been taken to exhibit at a local bazaar, he distinguished himself by escaping from his custodian, and remained triumphantly behind the wainscoting of an adjacent chapel for about an hour and a half, scraping with provoking and very audible diligence at the mortar of the wall. After several fruitless attempts he was recaptured, and again figured in public, to the great benefit of the funds, very many persons coming to see the wonderful "Rat on stilts." Both animals delighted to gnaw holes in an old curtain, to which they had access, and burrowed amongst its folds with infantine delight.

(4) A young female, successor to No. 3.—The male was much attached to this animal, paying her much attention. Unfortunately she died as a result of a broken leg, probably received in falling a considerable height from the sides of the cage. She was of a remarkably lively and frolicsome disposition, pattering about over the floor of the cage with the nimbleness of a Sandpiper.

(5) A young female.—Very small and poorly coloured; a remarkable greyish tinge showing on the fur.

(6) Adult female (successor to No. 4).—A handsomely marked specimen, rich dark fur in contrast to No. 5. The male seemed to like her well enough. It was hoped the pair would have bred. Unfortunately she was found dead one morning, though apparently in perfect health the day before. No cause of death was assignable. The male has survived all his wives, and is as lively as ever.

In concluding this article, I cordially recommend the Egyptian Jerboa to any naturalist in want of an out-of-the-way pet. Of convenient size, gentle disposition, engaging manners, and quaint shape, this little animal can be obtained at a very moderate price (say from four to seven shillings) of many London dealers, and is easily kept on crushed oats, millet-seed, or similar dry food. It does not require artificial heat save in the bitterest weather, provided it be kept indoors; it is neither delicate like a Marmoset, uncertain like a Ferret, noisy like a Cockatoo, nor vicious like a Budgerigar. Let the Jerboa have its food and cage perfectly dry, damp and especially fog being carefully avoided; see that the drinking-vessel is accessible, and give the animal plenty of clean dry hay, from which it will itself gnaw fragments to form its diurnal couch, and Dipus jaculus will live long and happily to delight the heart of its owner with its odd ways, lively movements, and docile temperament—a rodent Kangaroo, a mammalian Sparrow, and a vertebrate Sandhopper all rolled into one.