TRIBUTES have been paid to 'the grand old lady of Chester Zoo' as Martha the orangutan has died at the age of 59.

The zoo said it was "with an enormously heavy heart" that it shared news of the death of its Bornean orangutan, which had been at the zoo for more than half a century.

Martha had been in good health at the zoo, up until the last few years when she first began to develop age-related complications.

The zoo, in a post on its website, explained: "Vets and primate experts at the zoo had been helping her with daily medication and intensive geriatric care, including innovative laser treatment for her arthritis.

"Sadly, following a deterioration to her condition in recent months, the extremely tough decision was made to put her to sleep.

"Orphaned as a baby, Martha had to be raised in care by Barbara Harrison, an early pioneering orangutan conservationist who helped to set up the first orangutan rehabilitation centre in Borneo.

"Martha moved to Chester in 1966 where she went on to become a hugely influential part of the international conservation breeding programme working to ensure a safety-net population of Bornean orangutans.

"At an estimated 59 years, she lived well beyond her typical life expectancy which, in the wild, is estimated to be around 40 years."

Martha was a great, great grandmother, having had two daughters, Sarikei and Leia, who she lived with alongside their own offspring Dot, and a young female born in September 2023.

Mark Brayshaw, head of mammals at Chester Zoo, said: "Martha played a fundamental role in establishing the global conservation breeding programme for Bornean orangutans, giving birth to two daughters.

"With 29 descendants around the world, she’s had a truly remarkable impact on the future of her species.

“The enormous loss of rainforest habitat on the island of Borneo, to make way for agriculture, logging and unsustainable oil palm plantations, coupled with illegal hunting and conflict with farmers has led to a huge decline in Bornean orangutan numbers.

"As a result, the species is listed as Critically Endangered on the International Union for the Conservation of Nature’s (IUCN’s) Red List.

“Conservationists from the zoo and across the world continue to try and secure a brighter future for the Bornean orangutan – from conservation breeding in Chester; to reforestation projects in Borneo; to mitigating human-orangutan conflict; while promoting sustainable initiatives and creating a movement to clean up palm oil supply chains globally.”

Chris Yarwood, primate assistant manager and long-time carer for Martha of more than 26 years, added: “There really aren’t enough words to convey the awe and respect that I have for Martha, the grand old lady of Chester Zoo, and it feels incredibly strange to have to say goodbye.

“A wonderful mother and role model to her daughters Sarikei and Leia, Martha was a true ambassador for her species and fundamental to the establishment of the global conservation breeding programme, working to protect these charismatic, but sadly highly threatened animals.

“Caring for Martha has been a huge privilege. She’ll be hugely missed and will always hold a special place in our hearts.”

In addition, as a further strand of the zoo's work to protect highly endangered species from extinction, a small genetic tissue sample from Martha will be cryogenically frozen and carefully stored with the zoo's partners at Nature’s Safe, using some of the very latest scientific technologies.

The frozen tissue samples could go on to help restore lost genetic diversity in animal species threatened with extinction, potentially offering a vital lifeline for Bornean orangutans in the future.