Researchers say natural antibodies in the Tasmanian Devil immune system could help develop a vaccine to prevent the deadly facial tumour disease.

That could help increase the numbers of marsupials in the wild.

But scientists say there's another, less well-known, threat to the Tassie Devils.

Tasmanian Devils have a distinctive and blood-curdling snarl.

It's believed that's how the Australian marsupials got its name.

But although they may sound feisty, Tasmanian Devils are fighting to survive.

For decades, scientists have been working to save the endangered native animal - and having some success.

But there's a threat that's reversing years of hard scientific work, in an instant: roads.

John Hamilton, from the nature reserve Tasmanian Devil Unzoo, says it's the second biggest threat to the creatures after Devil Facial Tumour Disease.

"It's really unfortunate and unexpected that Tasmanian Devils have been the subject of roadkill."

Over the past six months, 49 healthy Devils were released into the wild.

Mr Hamilton says at least 17 have been killed by motor vehicles.

"Now the Tasmanian Devil is a carnivore but it mostly feeds on dead animals, so if a wallaby or a possum - and keep in mind, there are many, many more of these in Tasmania than there are in the rest of Australia - if a wallaby or possum is killed on the road, then unfortunately that's a food source for Devils, so that will attract Devils onto the roads at night."

Some scientists have developed a simple solution to warn animals about oncoming traffic.

Small solar-powered devices, about the size of a mobile phone, are placed 25 metres apart on wooden posts along each side of major roads.

Wildlife Biologist Samantha Fox explains how they work.

"When a car comes along, the headlights from the car activate the device, and it lets out flashing lights, blue and yellow flashing lights and an audible high-pitched noise, and that basically makes the animal on the road aware that something's coming."

A trial of the devices in north-east Tasmania found an 80 per cent reduction in roadkill.

Ms Fox says it's important preparation work for scientists who want to release more Devils which have been bred in captivity.

"What we want we want to be able to do is to put some of those Devils back into the wild, to not only increase the genetic diversity of those dwindling populations but to augment those populations with numbers of other Devils."

The Devils at the Tasmanian Devil Unzoo on the Tasman Peninsula will not be released into the wild.

Owner John Hamilton says they are crucial to the species' survival in raising awareness and raising funds to help keep the Tasmanian Devil from extinction.

The Unzoo are involved in monitoring the local wild population on the peninsula through its Devil Tracking system.

They're making sure it remains free from Devil Facial Tumour Disease, which has caused massive population declines since its first sighting in 1996.

"The numbers of Tasmanian Devils 10 to 15 years ago were estimated at around 130,000: now we might be down to 5,000 or 10,000 wild Tasmanian Devils and pretty much most of those are at risk."