Saturday was a sombre day for wildlife officials at the Borneo Rhino Sanctuary in Malaysia as they said farewell to Iman, the country’s only living Sumatran rhinoceros. The sole survivor had been suffering from uterine tumours since her capture in March 2014 and she finally succumbed to cancer over the weekend.

Iman eventually succumbed after a lengthy battle with cancer. © Borneo Rhino Alliance

“Iman’s death came rather sooner than we had expected, but we knew that she was starting to suffer significant pain,” Augustine Tuuga, the director of the Sabah wildlife department told the Guardian. Although staff at the sanctuary knew that this day would come, everybody was deeply saddened by Iman’s passing.

“May we be as strong as you in our urgent fight to save your species. May we be as courageous as you to never give up,” the team wrote in a Facebook update. The resilient rhino dodged death on several occasions over the last few years as a result of sudden blood loss, but she was nursed back to health each time.

Iman’s death comes just seven months after the passing of Tam – the last male rhino in Malaysia – who died of old age in May. The duo were not able to reproduce and, with no other wild Sumatran rhinos living on the nation's islands, they were left to live out their days under the care of staff at the Borneo Rhino Sanctuary. Egg cells and sperm were obtained from the pair in the hopes that they may be used in future artificial insemination programmes to help save the critically endangered species.

Sumatran rhino once roamed across Asia, from south-east India, Bangladesh, Myanmar and Thailand to the islands of Sumatra and Borneo. It’s believed the wild Malaysian populations are now extinct. There may be a small population in Kalimantan, Indonesian Borneo. Eric Dinerstein/Wikipedia

The smallest of the rhinoceros species, Sumatran rhinos once ranged across Asia as far as India, but poaching and deforestation reduced the population to just 80 individuals that can now be found scattered in the wilds of Indonesia. With such low population density and fragmented distribution the chances of the animals breeding in the wild are slim. The majority of the remaining rhinos are believed to be living in the dense mountain forests of Sumatra where it’s difficult to accurately track population size. This means that numbers could be even lower than estimated.

Captive breeding projects may be the last hope for the imperilled species, but Sumatran rhinos do not breed well in captivity. Since 1984, 45 rhinos have been captured from the wild, but these efforts have led to just four calves being born in sanctuaries and zoos. Sumatran rhinos struggle to reproduce in the wild partly due to the fact that females tend to develop uterine cysts and growths if they do not mate regularly.

While the loss of Iman was expected and is not a major blow to current conservation efforts of the species, her death does mark the extinction of Sumatran rhinos in Malaysia - a stark reminder of the monumental threat facing these endangered animals.

Top header image: Charles W. Hardin, Wikimedia Commons