@Bactrian Deer It was apparently due to a lack of space prior to the existing complex opening (with seperate exhibits for each adult). Contraception in apes wasn’t routinely used until the 1990’s in Australasia.
Puteri had four offspring with her father and brother:
Utama (F)
Born at Perth Zoo 19/06/1979
Still at Perth Zoo
Sire: Atjeh
Unnamed (M)
Born at Perth Zoo 10/12/1981
Died at Perth Zoo 20/12/1981
Sire: Puntjak
Unnamed (F)
Born at Perth Zoo 24/06/1983
Died at Perth Zoo 26/07/1983
Sire: Atjeh
Udara (F)
Born at Perth Zoo 06/02/1987
Died at Perth Zoo 07/09/1991
Sire: Atjeh
@Bactrian Deer It was an accident from keepers putting Puteri and Atjeh in neighboring enclosures, they were not in together but back then it was just a mesh fence that separated them, Utama was then conceived through the fence and without being on contraception at that stage in time it resulted in Utama. She is noted as different from the others and does many repetitive behaviors as a result of inbreeding. Such as putting finger over her eye and only eating certain things and only liking to be in with one other orangutan (Hsing Hsing) who has unfortunately since passed. But she is quite often front and center at the orangutan enclosure as she likes being able to see everyone at the enclosure closest to the viewing area. But others enjoy being at the front too like Sungai and Pulang
Thanks for all this info Johnpaul. Atjeh was housed apparently in the old dome cage at the end of the old orangutan (and chimpanzee but that was just one enclosure of a 1.1 pair) row (until mid 1981), and Puan and Binte (and Mawas once) were sometimes put in there with him for breeding, about a month at a time here and there, sometimes less. So Puteri must have been housed in the enclosure closest to the dome cage.
Actually apparently: Puteri cohabitated Atjeh's exhibit with him, from October 8th - November 19th 1978 which conceived Utama, according to a paper published by Dr Markham at the zoo.
Well there's a paper published by the mammal curator and orangutan studier Dr Markham (she was married to orangutan head keeper Charlie Broomfield at the time too so they were like the orangutan couple of the zoo, along with the Leeflangs who handraised the babies in '70s). I think perhaps wasnt realised that Puteri could get pregnant so young, so with juggling/revolving the large orangutan colony between only 7 small exhibits, probable that Puteri was put in with Atjeh for a while, as she was handraised couldnt go back in with Puan dont think, and Puteri got pregnant which was almost certainly unintended (plans to breed from her were a few years away still believe at the time, around Hsing Hsing's arrival time from Singapore in '83 was probably when they really wanted to start Puteri breeding, but she'd already had two or three babies by then;
I think when she cohabitated with her brother Puntjak too soon after, that they didnt really expect him to be able to sire yet, and lo' and behold he and Puteri conceived together. Would be a touchy subject understandeably as inbreeding always is especially with highly intelligent mammal species. I think the zoo just sort of vaguely relays the story of how Utama was born - the fact she was neutered too of course also supports what the keeper told you as there was nothing to be gained in generational breeding from Utama's birth.
