Years ago while visiting my home zoo (Milwaukee County) I remember having a discussion with a zookeeper about how hybrid orangutans (bred from one sumatran and one bornean) are to be phased-out so that each species' genes can be pure. Milwaukee has 1 hybrid orangutan, Tommy, who is getting up there in age. I'm curious to know if anyone knows of any other, or about how many, hybrid orangs there are left across the country or the world?
Colchester Zoo in the UK had until very recently an old male hybrid called Rajang - he died a few months ago. 'Baby bump' orangutan dies aged 50
There are just above 80 hybrid Orangutans in North American zoos, with the most recent one being born in 2015. Compared to Europe, which currently has 19 hybrid Orangutan, with the last surviving one being born in 1996, and non currently in breeding positions, unlike the North American population.
There's a Primate/Orangutan sanctuary in Florida(?) that has a large number of hybrids, including several adult males. Orangutan studbooks list the hybrids though you may have a long search through the lists to pick them all out.