Scientists working with a group of koalas at Longleat have discovered vital genetic clues which may help to secure the long-term survival of the iconic Australian marsupial in the wild.
Koala numbers are decreasing at an alarming rate due to a combination of disease and habitat loss.
It has been estimated there are now less than 100,000 koalas in Australia with the surviving populations becoming increasingly fragmented and suffering from a series of illnesses caused by their limited genetic diversity.
This, combined with a loss of habitat, resulted in the International Union for Conservation of Nature downgrading their status from ‘least concern’ to ‘threatened’ in 2016.
A ‘threatened’ species is likely to become endangered unless urgent action is taken to reverse the decline in numbers.
Up to a third of southern koalas suffer from a form of kidney disease while their northern cousins have been decimated by cancers and a form of HIV.
All three disorders have a genetic link and now researchers from the University of Nottingham’s School of Veterinary Medicine and Science, working with keepers at Longleat, believe they have identified a genetic mutation and a retrovirus present in the southern koala population which may help to protect against all three of them.
The research is being led Dr Rachael Tarlinton is Associate Professor of Veterinary Virology.
Tragically one of Longleat’s southern koalas, a female called Wilpena, died as a result of the kidney disease known as oxalate nephrosis.
“In the case of koalas, it’s hard to get information on disease, health and reproduction when you have to catch animals that are up 50 metre tall trees as they are in the wild,” said Dr Tarlinton.
“Much of our work can’t be done without animals held in zoological collections and, while Wilpena’s death was extremely sad, it does look as though the genetic information she has provided us with could provide vital clues to help save the population in the wild.”
“Koalas only live in Australia and only eat eucalyptus leaves so the maintenance of natural habitat and disease resistance are vital to the future of this most popular of species,” she added.
Dr Tarlinton and her team believe they have identified a retrovirus within the southern population that helps protect them from the diseases which have affected the northern koalas.
She also believes they have worked out the genetic mutation that causes the kidney disease which killed Wilpena.
“This has the potential to be a genuine scientific breakthrough which will allow us to design tests which could have taken us years to develop without the information gained from Wilpena,” she added.
Dr Tarlinton is also hopeful the new information will help to develop cross-breeding programmes with a view to eventually eradicating the genetic mutation which causes kidney disease and also spreading the retrovirus which helps protect against the cancers and HIV.
“Wilpena’s death was a huge blow to the entire team here at Longleat and, whilst we always knew this disease was prevalent within the wider koala population, it was still extremely difficult for us to come to terms with,” said Longleat’s Graeme Dick.
“Dr Tarlinton’s work is incredibly exciting and, if it can help to protect and safeguard populations in the wild, it will be a real game-changer and also mean Wilpena’s legacy will live on,