Translocation and acclimatisation

The first consideration in acclimatisation is to place the animals in a stress-free environment. The stress involved in the capture and/or shipping of animals, particularly those which are wild caught, or species, such as the agile wallaby, which are naturally of a nervous disposition, is considerable (Meadows, unpublished). The six deaths in 1976 all occurred during or immediately after translocation - four out of a shipment of eight agile wallabies were dead on arrival at the Zoo, post mortem examination showing the cause of death to be cardiac tamponade induced by the psychogenic stimulation of loading in Australia. The other two deaths were of brush-tailed rock-wallabies which had been caught and translocated to the Zoo as part of a research project. One animal died from injuries sustained in its violent attempts to escape while recovering from the influence of a neuroleptanalgesic, and the other died from shock.

Incoming animals are placed into the quarantine area for a minimum of seven days, regardless of their origin. During this period the animals are observed several times a day, routine faecal egg counts are carried out for page 149 the detection of parasite burdens, and routine anthelmintic treatment given with the food.^* As soon as possible after arrival animals are weighed, sexed and identified by means of ear-nicking (Karsten 1975).

The quarantine buildings and yard are entirely surrounded by a three metre concrete block wall, and covered with a roofing of wire mesh. Thus animals contained within the quarantine area are unable to see anyone except the staff assigned to look after them, and stress from sight and sound of humans is minimal. Only assigned Zoo staff, the veterinarian and Department of Agriculture inspectors are allowed access.

Animals are allowed free access from a 5 × 4 metre loose box to an outside concrete yard measuring about 15 × 5 metres. The concrete floor of the loose box is covered with a layer of hay or straw, and several bales of hay are placed to form small hideouts for the animals.

Animals adapt quickly to the presence of a quiet human being, and stress is thus kept to a minimum. However, wild-caught animals and nervous species require quiet handling throughout their lives. Food is provided in the form of a zoo-animal cake containing 14% protein, fed at a rate of approximately 2 kg cake per 100 kg animal. A small amount of lucerne chaff is given, and hay and water provided ad lib. With such a dry feeding regime, no nutritional scour has been noted.

Once animals have become reasonably quiet, are eating well and are cleared by the veterinarian as being free from disease they are transferred to their outside enclosure.

Handling and Restraint

Animals are caught by one of two methods. The most common is the use of a large catch net. This is made of double strands of 3 mm brushed nylon cord with a mesh of about 8 cm square and is 2 m high and 10 m long. It is laid on the ground and the animal to be captured is driven quietly across it. As the animal passes over, the net is lifted and the animal tangled in the mesh. Hoop nets may be used but are less satisfactory. Quiet animals can be caught by hand at the base of the tail.

Once caught, animals are restrained by placing them into a sack, or if they are reasonably quiet they are carried on one arm by placing the forearm page 150 across the top of the animal's body and then between its hind legs, gripping the base of the tail, the animal facing the operator. Once held like this a wallaby can be carried with little stress to either itself or the operator.

Enclosures

These should be as spacious as possible. Although animals have bred in enclosures of about 6×3 metres, at least three times these dimensions are recommended (Bergin 1976). The enclosure sizes at Auckland have been a minimum of 20 m × 10 m, and two years ago three enclosures were made into one large one for the exhibition of a mixed group. After enlargement the measurements were 40 m × 20 m. Currently this contains 1 eastern grey kangaroo Macropus giganteus, 9 common wallaroo Macropus robustus, 8 agile wallaby, 1 parma wallaby and 6 tammar. The move has been very successful, and interspecific interaction has so far been confined to periodic sparring matches between a male agile wallaby and the second oldest male wallaroo, who despite his greater size usually is the first to break contact.

Perimeter fences are a minimum of 2.5 m high - more to keep out feral dogs than to keep in the wallabies.

When new animals are introduced into an enclosure wire fences are made more visible by hanging them with hessian as panicky animals will bound straight into a wire fence.

The floors of most enclosures are sanded to a depth of at least 20 cm. Earth and grass floors are not favoured except for large enclosures on a hillside in which are kept two colonies of rock-wallaby. The extensive nature of these ensures the preservation of adequate ground cover.

Enclosures should be well planted with trees and shrubs protected by guards. These not only give shade, but allow escape and afford protection from animal interactions. They are also aesthetically pleasing, and Auckland enclosures have been planted out with Australian native plants to represent more fully the Australian zoogeographical region.

If adequate trees, shrubs, rocks and logs are provided there is no need for formal shelters. However, in the mixed exhibit there are two large shelters, each 4 × 3m, in which food troughs are placed in summer, and into which hay is placed in winter as bedding material (small amounts being added daily until the bed is up to 30 cm thick by 3 months at which time it is all page 151 cleared out). Provided that an adequate amount of fresh hay is added daily, no disease problems arise, and the animals enjoy the warmth and comfort of the bed.

Enclosures are cleaned every morning. Faeces are picked up by brush and shovel wherever practical, and sanded enclosures are thoroughly raked to expose any contaminants to the actions of sunlight and wind.

Food and water bowls and troughs are cleaned daily.

Feeding

Animals are fed once daily, in the afternoon, using the same system as for the quarantine animals. In addition occasional green food is given, such as grasses, tree or shrub leaves, bamboo, green vegetables, etc. Lettuce should be fed sparingly as it predisposes to diarrhoea. All food is placed in troughs to reduce the possibility of ingestion of parasitic ova or other contaminants. Water is provided by automatic drinking bowls placed about 30 cm above ground level. From time to time a young animal may need to be hand-reared (Wilson 1971) and for this a lactose-free diet should be used to avoid the occurrence of nutritional diarrhoea or cataract formation (Stephens 1976, Finnie 1976).

Breeding

The tammars mature sexually at about two years in males and at about one year in females, which continue to breed throughout life. They are seasonal breeders and in the southern hemisphere produce young in January (Barker 1971). Parma wallabies breed mainly in the spring, while red-necked wallabies breed all year round. The present colony of agile wallabies appears to be exhibiting similar behaviour to the tammar wallabies.

Currently no selective breeding is carried out, and any male may serve an oestrous female of the same species. Eventually selection will be carried out for females by the removal of male pouch-young, a technique used successfully at Adelaide Zoo (Dunn 1972).

In the past colonies have suffered from two main disease problems - the first, lumpy jaw, has been a common problem in many zoos (Wallach 1971, Barker, Calaby and Sharman 1963) and is now known to be caused by Fusiformis page 152 necrophorus with secondary infection by a large range of bacteria. While the disease appears refractory to most forms of treatment, Vibramycin has been effective in at least one case at the Auckland Zoo (Smith, pers. comm.). The second, pneumonia, has been a salient post-mortem finding in many instances, and is thought to have been induced by lowered bodily resistance resulting from stress or sub-clinical infections. Many cases occurred shortly after translocation, but no common organism was isolated.

Preventative Medicine

The current disease prevention programme is based on accurate observation and recording by well trained staff, and has virtually eliminated disease problems during the last two years. Every animal is closely inspected each day, as routine, and any change in behaviour or illness is reported immediately. Keepers' observations are recorded in a daily diary kept at the feed shed, and include group behaviour as well as individual. Each animal has its own record card, on to which are transposed all relevant observations, including matings, changes in habit, sighting of pouch-young, dietary changes or illness, treatment, and transfers. Regular collection of faecal samples for examination for oocysts and for worm egg counts, plus routine treatment with anthelmintics at three-monthly intervals has completely eliminated intestinal parasitism. Coccidiosis has never been diagnosed, and no coccidiostat is added to the food. No other vaccinations or procedures are carried out, except that whenever practical animals are weighed.

Treatment

Any animal appearing sick, or showing loss of weight, is transferred to an isolation pen where regular attention can be given without stress, either to the individual animal or to the composite group.