What is a Degu? The jury is still out. The first Europeans to set eyes on them in the eighteenth century regarded them (incredible as it might seem today) as some type of squirrel. That is now known to be way off the mark. More recently the consensus of opinion is that the animal is an aberrant rodent more closely related to the chinchilla or the cavy, with which it shares certain similarities. Although the latest genetic research raises the suggestion that it may not be a rodent at all, but a lagomorph and therefore more closely akin to rabbits, hares and pikas. But maybe we shouldn't make too much of this. Classifying organisms into strict zoological groupings is largely a man-made discipline and there will always be a few species that cannot be so conveniently pigeon-holed. For the sake of this article, I will continue to address them as rodents until research yields the truth.

Occasionally referred to as Octodonts (on account of the shape of the grinding surface of their molar teeth, resembling the figure '8'), the Degu is diurnal, active and inquisitive (the last quality one of the hallmarks of the worldwide success of rodents). It is also an animal very much in the ascendancy. Ten years ago few lay people had heard of it, much less encountered one, but now more and more often it is offered for sale in pet shops.

The Octodont family evolved in the early Oligocene (some 36 million years ago). There are now thought to be four species comprising the genus Octodon, of which at the time of writing only Octodon degus - let's call it the Common Degu - is to be seen in captivity in Great Britain. For many years there were just two other species recognised. These were Bridges' Degu (Octodon bridgesi) and the Moon-toothed Degu (O. lunatus). A fourth species, Octodon pacificus, has only recently been described, despite the original animals being collected as long ago as 1959. The Common Degu is slightly smaller than the other species.

Although it can take time to build the animal's trust, it is disinclined to bite. Like many other rodents, however, the tail is easily shed, and so one must avoid grabbing or restraining the animal by its tail. If the tail is grabbed suddenly, the skin and fur is stripped off (leaving the degu apparently none the worse for its experience), leaving behind bare bone. Occasionally the animal will then proceed to bite off the naked vertebrae and tendons. If it does not, the bone, deprived of a blood supply, withers and falls off anyway. The tail does not regrow.

Degus communicate with a variety of high-pitched whistling and growling noises. A common problem with captive degus is cataract, but so far no one has been able to suggest what the cause of this is likely to be.

Distribution

In the wild, the Common Degu is found in the Andes mountain range in northern and central Chile. Reports in earlier zoological tomes that the species also occurs in neighbouring Peru are now thought to be erroneous and based on a single specimen, almost certainly an escaped animal, having once been caught in that country.

Habitat

Degus are found in relatively open habitat where potential predators are easy to spot. They construct a maze of burrows. Debris left at the entrance holes in the form of sticks, stones and droppings may serve as territorial markers. The animal does not hibernate, but a certain amount of food may be stored for winter use, when food is otherwise scarce.

Density

Refreshingly, Octodon degus remains a common species, with population densities varying from 10-260 animals per hectare, although 40-80 per hectare is probably nearer the average; and in some agricultural provinces it is even considered a pest. Obviously any communal species such as this should be kept in pairs or small colonies in captivity, not as single animals. If the cage is big enough, it is sometimes possible to allow them to share with other species. Since degus should NOT be given standard rodent mix (for the reason I shall expound upon later), any companion animal must be able to thrive on the degus' diet. At one point I had two male degus living in an indoor aviary with two chinchillas and four Zebra Mice. This experimental mixing went well, although the mice did seem rather intimidated by their larger cage companions, and eventually I removed them.

Accommodation

Degus, being most active in the morning and late afternoon, appeal to owners who want to see their pet do more than just sleep. A roomy, tall cage is required. Degus are extremely destructive to wood or plastic, so cages must be made of galvanised metal and weld mesh. The mesh must be small enough to prevent the escape of new-born babies, a future consideration which is often overlooked when initially deciding on the choice of cage. If wood shavings are used, make sure they are coarse (i.e. not too fine) with minimal dust content. Excessive dust is irritating to mucus membranes and there is some speculation it can even precipitate pneumonia. Avoid pine wood if at all possible, as there is evidence the oil from such wood can be harmful to small mammals. Some rodent-keepers remain staunch advocates of wood-based cat litters (in the form of compressed sawdust pellets). Personally I don't like this material. I find that most rodents will chew it into a very fine and unpleasant dust. In doing so, they ingest a fair quantity of it and, being so desiccated, it expands when it encounters the moist environment of the gut and can cause impaction. Furnish the cage with a wooden sleeping box (which will need replacing periodically), wide-diameter pipes, and hardwood branches for climbing and gnawing. Wood from (unsprayed) fruit or willow trees is ideal. Scrub the branches well in a mild detergent to remove mould, fungal spores, bird droppings, etc, then allow them to dry before placing them in the cage. The bark should be left on, as not only will this provide occupational stimulation for the Degus that will enjoy stripping off the bark, but it provides valuable trace elements as well.

Degus enjoy an occasional dust bath in chinchilla sand (available from most pet stores). A gnaw stone helps prevent the incisors from becoming overgrown, and a cuttlefish wired to the inside of the cage helps strengthen teeth and prevent broken teeth. The incisor teeth are orange in colour. Whitening of the teeth is usually indicative of a serious health problem.

Droppings are dry and inoffensive. Degus are clean animals which will not offend even the most house-proud owners, and cleaning out the cage once a week is normally quite sufficient. I do not clean out the cage when degu babies are present.

Degus are hardy animals and, in temperate climes, there is no good reason why they cannot be kept outdoors as long as a few cardinal rules are obeyed: (1) Remember they have chisel-like teeth and will gnaw at anything, and so the cage must be constructed from suitably indestructible materials. Before I knew any better, I once kept a breeding group of degus in a large rabbit hutch and I was always having to patch it up with off-cuts of wood to prevent the animals escaping, until eventually I moved them out before the hutch disintegrated totally. If a degu escapes inside, it can be recaptured; one that escapes outdoors is gone for good. (2) The cage should be designed and sited in such a way that cats, dogs, wild foxes, feral ferrets, owls, and other predators cannot attack the animals through the wire mesh. (3) The animals must have adequate shade from the sun and cover from rain and wind. Like other montane species, the Degu is intolerant of excessive heat, and in very hot weather ways must be found to keep the animals cool. (4) Depending on location, it is probably advisable to bring the animals inside during the coldest part of the winter if only for their own comfort. Most people, however, are content to keep them in an indoor location, where, after all, they can be observed in greater comfort.

Diet

Degus are sugar-intolerant - they are prone to diabetes, being unable to metabolise fructose (the naturally occurring sugar in fruit) - so I don't give mine any fruit or vegetables. Another common cause of diabetes is obesity, as it is with the human animal. An animal suffering from diabetes will drink an excessive amount and will eventually waste away and die. In the wild, degus eat seeds, grasses, herbs, leaves, bark, and other plant material. In captivity, instead of feeding ordinary rodent mix (which can have a fairly high sugar content), I give them a good base food of chinchilla pellets to which is added a proprietary alfalfa (lucerne) based guinea-pig mixture. Excessive maize in the diet can cause sluggishness, and I know of one person who used to painstakingly remove the maize and linseed from the proprietary mixes, but her animals were among the healthiest I had ever seen.

Other keepers offer, as an occasional treat, borecole (kale), broccoli, English marigolds (Calendula), fresh leaves from growing garlic, fresh or dry herbs, Jerusalem artichoke, plain canary seed, seeding grasses, sweet potato, raisins, or sugar-free water biscuits. Good quality hay is essential, both as a food and bedding material, but it must be replaced at regular intervals before it gets damp or soiled. A 'monkey nut' or two or three sunflower seeds can be given twice a week to each animal.

There is a lot of confusion regarding the type of drinking water that is safe for degus. This is a matter that needs to be clarified urgently. Some keepers suggest hyperchlorinated water (i.e. water with added chlorine), whilst others adamantly claim that only hypochlorinated water (water with the chlorine removed) should be given. I know some keepers who go to the expense of buying bottled or mineral water to give to their degus. So what is the truth? Admittedly, tap water does contain high levels of chlorine, but I have always used ordinary tap water for all my animals' drinking water and I have never had any problems. If you are worried about the chlorine content of tap water, I suggest leaving it to stand in a well-rinsed bucket overnight. Chlorine is a very unstable chemical and soon evaporates into the atmosphere.

The water should be provided in a drinking bottle, or, failing that, a heavy ceramic dish, as plastic will invariably be gnawed. Drinking bottles made of glass are best if you can find a source of supply, but that may not be easy as they have been largely superseded by the cheaper but inferior plastic bottles.

It has been suggested that vitamin C should be added to the drinking water on alternate days, as this vitamin, whilst being generally beneficial, may also help prevent mouth disease, to which these animals seem quite susceptible. As with so much else about degus, this is another hypothesis which has yet to be proved, but even in fairly large quantities the vitamin C is normally very safe. Being one of the water-soluble vitamins, it breaks down easily in the body, unlike fat-soluble vitamins that are stored in the body and can, in excess, sometimes prove toxic.

Reproduction

Sexing prevents few problems and, even in young animals, it should be quite easy to tell the sexes apart, the anal-genital distance being approximately twice as far apart in males as in females. In mature specimens the testes of the male are also clearly visible.

In captivity the degu breeds throughout the year, whereas, in the wild, it appears to be more of a seasonal breeder. Sexual maturity is attained at about six months - although it can be considerably earlier. My first pair of degus mated successfully at just three months of age. Like the rabbit, the female degu does not have a regular breeding cycle but seems to be an induced ovulator; in other words, it is the physical act of mating that stimulates egg production. The gestation period is 90 days. Litter size varies from 1-10, but such large litters are rare, and 5-6 young is closer to the norm. Babies are born usually with a complete or, at any rate, thin covering of hair, but never naked. Eyes open at birth or within the first day or two. They are mobile almost from the moment of birth. You can safely leave the father with the babies as he will not harm them. The dam, I have found, can be very protective towards her new-born offspring and may at this time deliver an occasional not-too-painful nip to its human owner if it feels his/her hand is straying too close to the precious babies. Weaning occurs at about four weeks of age, but I generally retain the young to remain with their parents for at least eight weeks. Longevity is between 5-7 years.

Inbreeding is likely to be a serious issue in the future. Primarily as the present stock is derived from a very small founder population. At present degus occur in few other coat patterns - which is as it should be, as the deliberate breeding of abnormal colour mutations (not only with rodents, but birds and fish too) is ruining the captive gene pool of so many species.