The death of a 25-year-old female Sumatran rhinoceros on the island of Borneo means that the species is now officially extinct in Malaysia. Named Iman, the animal had been the only one of its kind in the country since May, when Malaysia’s last male passed away.
A critically endangered population of Sumatran rhinos still clings to existence in Indonesia, though with fewer than 100 individuals remaining, the need to step up conservation efforts and breeding programs is becoming increasingly pressing.
Conservationists had hoped that Iman might play a starring role in the fight to revive the species after she was captured in 2014 and paired with a male rhino named Tam, who had been residing at the Tabin Wildlife Reserve since 2008. Yet it was later discovered that Iman was suffering from uterine tumors – possibly resulting from having gone too long without breeding – and that she was infertile.
All hopes were finally dashed when Tam died earlier this year, and after living alone for the past six months, Iman has now succumbed to her cancer, her carers at the Borneo Rhino Sanctuary in the Tabin Wildlife Reserve confirmed. Her death has been described as “a natural one” by Sabah State’s environment minister Christine Liew, BBC News reports.
There are five species of rhino, two that live in Africa and three that reside in Asia. The Sumatran rhino is the smallest, and has two horns like the two African species. The Sumatran, Javan and Black rhino are listed as "critically endangered" on the IUCN Red List, while the Indian and White rhino are listed as "vulnerable" and "near-threatened", respectively.
While poaching and habitat loss have contributed massively to the species’ decline over the past few decades, isolation is now thought to be the biggest threat to the survival of the Sumatran rhino, as they are now so few in number that they rarely get the chance to meet and breed in the wild. Females who go too long without mating can develop cysts in their reproductive tracts, rendering them infertile – as was the case with Iman.
Back in the mid-1980s, some 800 Sumatran rhinos were estimated to occupy the dense forests of Southeast Asia, with their territory reaching all the way up to the foothills of the Himalayas. Yet the grimmest estimates place current numbers at just 30, raising fears that the species could soon disappear altogether.