The oldest Javan Moloch gibbon in captivity has died at Winnipeg's Assiniboine Park Zoo at the age of 50.
Dying of natural age-related problems earlier this week, the lesser ape named Bobby-Jean was one of the last of her species.
Also known as the silvery or grey gibbon, Hylobates moloch is native to the island of Java, Indonesia, and is critically endangered.
With only 40 left in captivity at seven zoos outside of Java, and a declining wild population of 350 due to loss of habitat from logging, poaching and the establishment of plantations, primate experts said the species could be lost from the wild within 40 years.
Bobby-Jean was captured in Java in 1958 and arrived at the Winnipeg zoo in Western Canada in 1964, at the same time as her mate Billy-Joe.
The pair produced nine surviving offspring, which were sent to Australia, the United Kingdom, Russia, Germany and California to participate in a formal breeding program.
Zoo officials said Bobby-Jean, the oldest silvery gibbon on record, enjoyed observing visitors with a mirror, which she manipulated to look over her shoulder.
"She will be greatly missed by staff and numerous visitors, who always made a point to stop and chat with this appealing and gentle zoo resident," officials said.