Another comprised the orang-utans of Sumatra, who were said to take men captive and set them to work as slaves.
Orang-utans are the only living great apes in Asia, but they could become extinct in the wild within just 20 years.
Today around 25 young orphan orang utans are housed in the nurseries, in addition to those free in the reserve.
Jack-fruit or durian, the tough spiny hide of which is torn open with their strong fingers, forms the chief food of orang-utans, which also consume the luscious mangustin and other fruits.
A year ago the Thai embassy in London received strong evidence that the orang-utans had been smuggled illegally from Indonesia.