ha nd-rea ri ng

Feeding a hand-reared Andean condor and King vulture

at Wassenaar Zoo Vulturgryphus and Sarcoramphus papa

P. ZWART’ & J. W. W. LOUWMANZ ‘Fakulteit der Diergeneeskunde, Rijksuniversiteit Utrecht, Yalelaan I , 3508TD Utrecht and ZDirector, Zoo Wassenaar, Rijksstraatweg 667, 2245 CB Wassenaar, Netherlands

The successful hatching and rearing of birds of prey is still a comparatively rare event and when hand-rearing is necessary it is attended by particular difficulties.

At Wassenaar Zoo a pair of Andean condors Vultur gryphus successfully mated in 1977 but killed and ate their newly hatched young. The following year it was decided to remove the egg about one week prior to hatching and incubate it artificially. Some weeks earlier the first egg produced by a pair

of King vultures Sarcoramphus papa had also been taken for incubation.

We could find no record of hand-rearing a King vulture, but both species are known to feed regurgitated prey to their chicks (Lint, 1960; Cuneo, 1968). Of great interest there- fore were the reports on hand-rearing an Andean condor at Amsterdam Zoo (Dekker, 1967) and Andean condors and American black vultures Coragyps atratus at West Berlin (Klos, 1973) by using predigested meat

Plate 1. Hand-reared Andean condor Vultur gryphus (left) aged 37 days and King vulture Sarcoramphus papa aged 77 days at Wassenaar Zoo.

HAND-REARING 277

incubated with the pancreatic enzyme trypsin.

We used a variation of this successful technique by predigesting the food with pepsin and hydrochloric acid. An advantage was that acidification might help to prevent bacterial growth during incubation and might also make the food more palatable.

An artificial gastric juice was prepared from: 5 g Pepsin, 4 ml HC1 12% and 200 ml water. Equal weights of the juice and food were mixed and incubated for one hour before each feed at 36'C. After this time the flesh was markedly softened and the fluid was decanted. The pH of the end product was 45, which was safe to feed to the young birds.

Bacteriological examination revealed that when small pieces of day-old chicks of domestic fowl were incubated for one hour, no bacterial growth was obtained. After 24 hours yeast cells had developed. A second batch of chicks, which were heavily con- taminated with bacteria, revealed no increase in the number of colonies producing bacteria after 24 hours. At the end of this period a diminution of E. coli in favour of cocci was observed. It appears therefore that, although bacteria are not destroyed by the technique, their growth is effectively prevented.

As a deliberate policy, the food for the first morning feed was not incubated overnight but prepared early the same day. Both the young birds preferred the livers and intes- tines of adult mice and whole furless baby mice to minced day-old chicks.

As the skeleton of a very young animal is poorly calcified, for example in a day-old domestic fowl chick the Ca/P ratio is about 1 : 2.4, mineral supplements are essential. At every meal we added 4% of CarniconR, a vitaminlmineral preparation containing 11.5% Ca and 05% P, which is specially prepared for and flavoured to appeal to large mammalian carnivores.

When hand-feeding the two young birds, the keeper in charge, Mrs 1. van de Voort, found that by making a ring with her fingers through which the bird could insert its beak, or by simply holding the beak between two fingers, active prehension and swallowing

I vulture condor

m 2 02

0 1 2 3 4 5 6 7 8 9

Fig. 1. Growth rates of the hand-reared King vulture and Andean condor chicks. 1. first intake of unpredigested food; 2.100% raw food.

weeks

were initiated. This avoided the stress associ- ated with force-feeding.

The growth rates of both the young and the ages at which unpredigested meat was accepted are shown in Fig. 1.

ACKNOWLEDGEMENT We thank the Wuppertal Zoo for their kindness in allowing us to keep their d Andean condor on breeding loan.

PRODUCT MENTIONED IN THE TEXT CarniconR: a vitamin/mineral supplement manu- factured by Fa. Trouw, Putten, Netherlands.

REFERENCES CUNEO, F. (1968): Notes on the breeding of the king vulture Sarcoramphuspapa at Naples Zoo. In#. Zoo Yb. 8: 156-157. DEKKER. D. (1967): Hand-rearing the Andean condor Vulturgryphus at Amsterdam Zoo. Int. Zoo Yb. 7: 227. KLOS, H. G. (1973): Hand-rearing Andean condors Vuhr gryphus at West Berlin Zoo. Int. Zoo Yb. 13: 112. LINT. K (1960): Notes on breeding Andean condors at San Diego Zoo. Int. Zoo Yb. 2: 82.

Manuscript submitted 4 December 1978