Good news for endangered Sumatran rhinos
Genome study indicates prospects for saving critically endangered species now found in small numbers on the islands of Borneo and Sumatra.
A genome study involving the last remaining populations of the Sumatran rhino – a lonely rainforest inhabitant – provides what scientists have called good news on the prospects of saving this critically endangered species.
According to a study, the two extant wild populations of this rhino on the islands of Borneo and Sumatra were found to have good genetic health and surprisingly low reproductive levels. Experts say only around 80 of the rhinos remain after a distinct population of the Malaysian Peninsula has become extinct in recent years. The Sumatran rhino, the closest living relative of the woolly rhino which was one of the notable species of the last Ice Age known for its two small horns and a thin coat of reddish-brown hair.
“With such small population sizes, we expected higher reproduction in existing Sumatran rhino populations. So these results were good news for us, ”said Nicolas Dussex, post-doctoral researcher at the Center for Paleogenetics in Sweden who helped lead the study published in the journal Nature communications. “Additionally, while the plight of the Malaysian population serves as a stark warning of what could happen to the two remaining populations of Sumatra and Borneo, our results suggest that it may not be too late to find ways. means of preserving the genetic diversity of the species. . ”
Researchers sequenced the genomes of seven rhinos from Borneo, eight from Sumatra and six from the Malay Peninsula population considered extinct since 2015.
The Sumatran rhino is the smallest of the five rhino species in the world, weighing around 700 to 800 kg. The elusive rainforest inhabitant, the most vocal species of rhino, remains solitary except for mating and rearing offspring. It once had a wide range in Southeast Asia, from the Himalayan foothills to Borneo and Sumatra.
Poaching and destruction of homes by humans has devastated its population, with numbers dropping by around 70% over the past two decades.
“When it comes to the long-term survival of a species, genetic diversity is one of the key factors, as it allows adaptation to future environmental changes and disease,” said Johannavon Seth, student PhD and lead study author at the Center for Palaeogenetics. “So the fact that there is still a lot of diversity is very promising if we can be successful in maintaining it, of course assuming that we can reduce the impact of non-genetic factors as well.”
The researchers said that steps such as translocation of rhino formation – a costly and logistically difficult proposition – or the use of artificial insemination could allow beneficial gene exchange between the populations of Borneo and Borneo. Sumatra. This species has shown low breeding success in captivity and faces a high risk of inbreeding – mating with close relatives – in the wild due to its small numbers.
Inbreeding creates an increased risk of genetic defects and reduced genetic diversity. Scientists feared that reports of tumors and low fertility among these rhinos could be evidence of a dangerously inbred population.
“It’s important to remember that the Sumatran rhino is still on the brink of extinction due to non-genetic factors,” said Love Dalén, professor of evolutionary genetics at the Center for Paleogenetics and co-author of the study. “So the hope, albeit low, that these results offer is that if we can solve the problems caused by habitat destruction and poaching, there is at least a chance that the survivors will not be doomed. by their poor genetic status, ”added Dalén. .