...the edge of its carapace, Cuban anoles, rhinoceros iguanas, and crested basilisks. The latter is a spectacular iguanid lizard from South America. The males, bright green in colour, have an erect fin-like crest running down the spine and upper section of the tail. The back of the head is also adorned with a crest.
Common iguanas have figured prominently in Melbourne Zoo's reptile collection for over a decade. The first breeding occurred in 1967 when a clutch of 22 young hatched after an incubation period of 65 days. Since then, successful breeding has taken place in 1970, 1973 (resulting in 2nd generation Zoo bred young), and in 1975 (adding a third generation). Eggs are incubated in damp sand or vermiculite at a temperature of 30°C. The incubation period is between 65 and 86 days, and the young are approximately 25 cm long at birth.
Iguanas are vegetarians and, in the wild, feed on leaves, flowers and, when available, fruit. The plants most favoured by these iguanas are milk thistle, melon dandelion, wild mustard, clovers and plantains. The success with these iguanas may well be due to adherence to this diet, which probably closely resembles their natural diet.
The Zoo also received a female perentie from Central Australia as a mate for the male which has graced the collection since 1969. This is Australia's largest lizard, attaining a total length of 2.4 metres or more. It will be many years before these specimens approach that size, although they are already sexually mature.
Eight species of reptile produced 83 young animals in total, including 28 boa constrictors. Boa constrictors are a favourite snake in zoos, being non-venomous, generally docile, easy to handle, and extremely good feeders. They are less temperamental in this respect than many snakes. Some of the young boas have been adopted by the Zoo's Education Staff who use them to introduce children to snakes and dispel some of the misconceptions many people have about these creatures.
Johnstone's crocodiles, which bred successfully last year, again laid eggs but these failed to hatch. The Zoo's female estuarine crocodile also laid eggs, which she unfortunately destroyed while trying to bury them in the hard floor of the exhibit. She had been provided with a large heap of sand in which to nest but this apparently did not meet with her approval. Crocodiles are not often bred in captivity and are also becoming less common in those parts of the world in which they naturally occur.
For a decade "Wilbur", a large male giant tortoise Testudo gigantea was the sole representative of his species in Melbourne Zoo. "Wilbur" was received from the Government of the Seychelles in 1965, and was approximately 30 years old on arrival. His time in Melbourne has been divided between heated winter quarters and green summer pastures. Each year the move requires more effort ("Wilbur" now weighs over 90 kilograms), and four strong keepers are necessary to move him on to the Reptile House.
In 1975, three more giant tortoises were received from the Seychelles Government. The largest of these is a male (weighing 68 kilograms), and the other two are young females with the big scales at a mere 36 kilograms and 32 kilograms respectively. Although these tortoises came from the Seychelles, they are not native to those islands. The thriving colony now within the Seychelles was introduced from the Indian Ocean Group of islands known as Aldabra in 1974.
All of the animals transferred to Werribee Park were tested for brucellosis, leptospirosis and tuberculosis prior to shifting. They were also vaccinated against the common clostridial diseases and tested and treated for intestinal parasites. Before handling and blood collection can take place each individual, except the smaller follow deer, must be chemically immobilised. This task is made much easier today by using the modern projectile syringe gun which can be converted to handle syringes from 1.5 ml to 25 ml capacity. Substantial doses of antibiotics and anthelmintics can be given to even the largest zoo animal without the stress of physical restraint.
Once again the Zoo was indebted to the Department of Agriculture Veterinary Research Institute for the valuable work done in various aspects of pathology and haematology. Now that its Wildlife Laboratory is functional, much of the data gathered over the past two and a half years is being used for reference, including 176 blood collections during 1976/77 which previously would have been unrecorded.
The Zoo's own veterinary laboratory has taken some of the load off the V.R.I. In the last two years by performing 900 faecal examinations for intestinal parasites in 1976/77. (600 in 1975/7).
The Royal Children's Hospital has made a generous donation of surplus equipment which has been put to good use in the Zoo's hospital and nursery. It consists of an hydraulic operating table, a mobile operating light, a hot air oven for sterilising surgical equipment and an isolette. It has been found that the survival rate of very young joey kangaroos has improved greatly since the isolette was installed in the nursery.
The University of Melbourne Veterinary Clinical Centre at Werribee has provided facilities for major surgery on five animals and X-rays of twelve animals during the year.