HAND-BEARING

Notes on the early hand-rearing of an orang-utan

and its subsequent reintroduction to the mother Patigo p y p a e i t s

MARILYN COLE, DIANE DEVISON, PATRICK J. ELDRIDGE, K. G. MEHREN & W. A. RAPLEYl Metro Toronto Zoo, POB 280, Wes t Hill, Ontario, Canada M1E 4R5

On 12 October 1977 a 3 offspring was born to a primiparous ten-year-old orang-utan at the Metropolitan Toronto Zoo, one of a group of five (1.4) Sumatran orang-utans Pargo pygtnaeus abelii normally exhibited together. Although it was her first birth, the mother had had previous experience in carrying an infant born two years earlier to the oldest 9 of the group, and had been observed at times to ‘suckle’ both this and another five-year-old juvenile with which she had seemed to develop a parental relationship. The birth, which took place mid-afternoon, was witnessed by keepers. The mother behaved as though frightened of the idant and made no effort to handle or clean him. Because he was suffocating with placenta covering his face, he was removed from the enclosure minutes after the birth to be resuscitated and cleaned. Once revived he was strong and active.

Bottle-feeding was started five hours later following an unsuccessful attempt to reintroduce infant to mother. A human milk replacer (SMA), diluted I : 2 with boiled tap water, was offered on demand. This mixture was further diluted on day 2, following a digestive upset, the concentra- tion then being gradually increased to I : I by day 8.

During the first 12 days the infant consumed an average of 45 nil milk per feed, at approximately zi-hour intervals. Between days 3-12 milk consumption averaged 375 ml per day, regardless of differences in formula strength. Dietary supplements (Avitron, Ferrocebrin and Calcium Sandoz) were introduced on day 9, but were discontinued the following day because of a minor digestive upset.

On day z the infant became depressed, inappetant and dehydrated, and his abdomen was distended with gas. He had not defaecated during

the first 24 hours. He was treated with fluids and electrolytes by subcutaneous injection. A warm water enema with K-Y lubricant was also administered. The enema tube ruptured a thin membrane which had apparently sealed off tlie lumen of the rectum. Gas and meconium were passed with force soon afterwards. The infant fed normally two hours later, and had regular bowel movements without further treatment.

A heating pad, at the lowest setting, was used for supplemental warmth on days I and z. By day 3, as the infant was doing well and seemed comfortable at room temperature (22-24Oc),

the pad was discontinued and only blankets were used for warmth. The idant was never placed in an incubator.

A rolled up fleece was offered initially as a surrogate mother. On day 4. however, when bits of fleece were found in the idant’s mouth, this was replaced with a rolled up towel. A bed was fashioned from a foam pillow covered with a soft towel; the infant would lie on his stomach on the pillow, all limbs outstretched to grasp the sides.

Close contact with the attendant was en- couraged. At night the animal would sleep in the attendant‘s bed, either on his ‘pillow bed‘ or on the attendant’s stomach. During the day the infant was frequently carried as the attendant went about her duties. On day 8 a cloth baby carrier, fastened to the attendant’s chest, was obtained and the infant was carried in this. Daily walks outdoors were started on day 8, and by the fourth day of this activity the infant stayed awake and looked about during the whole walk. Some observations on his early development are included in Table I. Hand-rearing was dis- continued on day 13, when the infant was successfully returned to his mother.

’Authors are listed in alphabetical order.

264 HAND-REARING

WEIGHT DAY (kg) DEVELOPMENT

I 2.0

3

4

5 7 1.93

I1

12 2.09

13

Eyes open Alert, responsive to noises. Holds onto attendant, eyes constantly on attendant’s face during feeding Content to lie by himself, waving arms and legs around, for 1-2

hours after feeding T w o lower incisors erupt Reaches out for bottle at feeding time Holds bottle while drinking, unassisted

Successfully reintroduced to mother

Table I. Development of a 3 neonate Sumatran orang-utan Pongopygrnaeus abelii during the 12 days of hand-rearing before he was successfully reintro- duced to the mother.

R E I N T R O D U C T I O N

The decision to attempt a second reintroduction was prompted by the observation, on day 8, that the mother permitted the two-year-old youngster to suckle, and that she appeared in fact to be lactating. Two days preparatory to the attempt she was separated from the rest of the group, and on the morning of day 12 the infait was brought to her sleeping quarters and shown to her. Although her first reaction was to touch the infant’s head with her finger, which she then sniffed, when the infant was then placed in the cage with her she made no further move towards physical contact and, except during the times when he was being bottle fed, she showed no interest. The infant was removed after about six hours.

On the following day the mother was tran- quillised with 50 mg Diazepan concealed in figs and an hour later the young orang-utan was rubbed gently with her faeces. This time, when he was displayed to the mother, she immediately

put her hands through the bars to touch him, and as soon as he was placed in the cage she picked him up and carried him to the back of the enclosure. During this sequence the infant cried continuously, but once the 9 had made a nest of wood wool and was lying supine with thc infant clasped to her chest, he quietened in n few minutes and remained so for the rest of the day. Within the hour, and several times subsequently, he was seen to be suckling.

Access to the public viewing exhibit was permitted for two hours on day 23 and was extended on each succeeding day. Except for the breeding 3, however, who was introduced on day 43, mother and infant were left segregated from the group for several months, in order that the young animal could develop without interference. The d showed no interest whatso- ever in the infant.

ACKNOWLEDGEMENTS The authors wish to thank staff members of the Metro- politan Toronto Zoo for the co-operation and involve- ment in the hand-rearing and subsequent reintroduction of this infant orang-utan.

PRODUCTS M E N T I O N E D I N TIIB TEXT Avitron: liquid vitamin supplement with vitamin D, manufactured by Lambert Kay Division of Carter- Wallace, Inc., Cransbury, New Jersey, USA. Calcium Sandoz: liquid calcium supplement nianu- factured by Sandoz (Canada) Ltd, Dorval, Quebec, Canada. Diazepan Roche: experimental purified form of tranquilher manufactured by Hoffmann-La Roche Ltd, Vaudreuil, Quebec, Canada. Perrocebrin: liquid iron/vitamin H co~nplex/vitamin C manufactured by Eli Lilly & Co. (Canada) Ltd., Scarborough, Ontario, Canada. K-Y Lubricant: sterile water-soluble lubricant manufactured by Johnson & Johnson Ltd, Montreal, Quebec, Canada. SMA: human milk replacer manufactured by Wyeth Laboratories Inc., Philadelphia, Pennsylvania, USA.

Manuscript submitted May 1978