Charles Sturt University (CSU) researchers are racing the clock to learn more about a virus threatening the world's last remaining Orange Bellied Parrots.

Only about 50 of the birds remain in the wild, in a breeding population which migrates from South West Tasmania across Bass Strait to spend winter on the mainland.

The species earned notoriety in the 1990s when the then Victorian Premier Mr Jeff Kennett called it a 'trumped-up corella' during debate over the relocation of the Coode Island Chemical storage facility in Melbourne.

CSU Professor of Veterinary Pathobiology Shane Raidal said although about 250 Orange Bellied Parrots were held in captive breeding programs, both the wild and captive populations were threatened by psittacine beak and feather disease (PBFD).

"The disease suppresses the immune system, causes feather loss and beak and claw deformities and can kill nestlings and fledglings very suddenly," he said.

"PBFD affects all parrots, but is a particular danger to small populations already under threat like the Orange Bellied Parrot."

Professor Raidal said the disease had delayed the establishment of a captive breeding program for the Orange Bellied Parrot as far back as 1985, but improved facilities and testing had kept the captive flock disease free between 1994 and 2006.

"In the 2007-08 summer breeding season, juvenile birds in the captive Tasmanian flock developed signs of the disease so all captive birds were tested and the wild population was sampled," he said.

"More than half the birds in the captive Tasmanian flock were found to be infected, and birds in the captive Victorian and South Australian flocks were also found to be infected."

Professor Raidal is part of a team of researchers from CSU's School of Animal and Veterinary Sciences, the Graham Centre for Agricultural Innovation, the University of Tasmania, the NSW Department of Primary Industries, Healesville Sanctuary and La Trobe University which has been studying the virus which causes PBFD.

"It's a very simple virus, just a single protein and a tiny piece of DNA, but it mutates very rapidly," Professor Raidal said.

"It changes so fast that we have not only found several different variants present within the flock, but within individual birds."

The research team has demonstrated experimentally a vaccine to protect against the virus would be possible, but Professor Raidal said the process of developing and approving such a vaccine may take too long to save the species."Sadly we have pushed this species into a position where this disease, which may not be an extinction risk to larger populations, could wipe it out completely," he said.