Tripa had been under the expert care of the zoo’s veterinary and primate teams for several years for a number of health-related problems – linked to a developmental condition he’d had since birth.Despite the close monitoring, expert consultation and care extended to him, Tripa’s condition and quality of life deteriorated and, in the interest of reducing his suffering, the very difficult decision was taken to put him to sleep.Sumatran orangutans are a critically endangered species with just under 14,000 left in the wild, pushed towards extinction due to habitat destruction for logging, the wholesale conversion of forest to palm oil plantations and hunting. The loss of Tripa is therefore devastating news to all of those who have looked after him since his birth at the zoo in October 2012. As well as being a successful part of the European endangered breeding programme for the species, Chester Zoo’s conservationists are also working in South East Asia where they are helping field workers in Sumatra to restore forest in which orangutans live.