The devil made him do it. Animal behaviouralist Bruce Englefield emigrated to Australia after falling in love with Tasmanian devils, working with others to save them from the facial cancer that was threatening them with extinction.
But he was shocked when nearly a quarter of healthy devils released back into the wild became road kill within weeks of their release.
The roads are as big a threat to the devils as the facial cancers, he says. His research estimates "millions" of Australian marsupials are killed on the Australian roads every year. The most vulnerable are kangaroos, wallabies, wombats and koalas, he says. The figures don't include birds or reptiles, also run over in large numbers.
At 75, Mr Englefield - previously a television technical director, animal behaviour counsellor and farmer in Britain - is now undertaking a doctorate in veterinary science with the University of Sydney.
To find out how many animals are being killed by cars, Mr Englefield is conducting a survey of anyone who rescues native animals. He wants to quantify the size of the problem (estimates vary wildly and hard data is hard to find), the number of wildlife carers, how much support they need and how they can continue to rescue injured animals as the amount of road kill increases.
"If you find a dead wallaby with a live joey, it can be alive in the pouch for three to four days," he said. With so much road kill, the government and the public had a choice of policy options: "You either bring in a policy to leave them there and let them starve to death, or take them out and euthanise them. I don't think the Australian public would go along with this. The only alternative, then, is hand rearing these animals, and if that is the decision you may need a lot of voluntary carers."
NSW's WIRES Wildlife Rescue responds to thousands of calls each year related to motor vehicle collisions.
Right now, it's the worst time of the year for road kill and injured animals.
It is currently receiving about 4000 calls a week about animals that have been injured on the roads and elsewhere, and the number of calls rose 19 per cent in the past year to 143,000.
Yet its spokeswoman said it was impossible to say accurately how many animals were killed or orphaned by cars each year.
She said it was difficult to identify why animals were coming into care because some may have been moved from the scene of the accident. Those which were euthanised on the scene, or orphaned, were not attributed directly to motor vehicle collisions, although they were often the result of these crashes.
It receives more calls to help animals in more populated areas where there are major roads located near areas of native habitat. "This is partly due to road traffic but also loss of habitat and just greater human-animal interaction in general," the spokeswoman said.
Some highways now have overpasses or tunnels to allow native animals to cross safely.
In Queensland, CSIRO's research has found vehicle strike is a major threat to koalas. In 2013, Fairfax Media reported 10,956 of the 15,644 south-east Queensland koalas that died between 1997 and 2011 were struck by cars, mauled by dogs, or died of stress-related disease.
But a six-year study of bridges and tunnels found many animals regularly used tunnels and bridges as soon as they worked out how to use them.
WIRES wants more of these crossings: "We are a long way from the ideal, but it would be great if organisations and government could work together to identify hotspots where safe animal crossings or rope bridges could be deployed to reduce the impact of our roads on wildlife."
Based in Tasmania, described by some as the road kill capital of Australia, Mr Englefield fell in love with Australian wildlife when he visited Tasmania on holiday in 2000.
When he visited a wildlife park about 150 kilometres east of Hobart, he saw devils for the first time.
"I was wowed, I couldn't work them out, and their behaviour with spinning and running, and everything they did, was different from anything I'd seen from other animals. They were unique. They fascinated me," he said.
He also saw that the zoo was for sale.
"To cut a long story short, we bought a zoo," he said.
"But it was the devil that brought me over here. I started the Devil Island Project and by running a wildlife park I had the thrill of seeing devils on a daily basis," he said.
Researchers within the Tasmanian government's Save the Tasmanian Devil Program have since pioneered new approaches that have reduced the road toll of devils being released.
As part of his research Mr Englefield is undertaking a scientific appraisal of a virtual fence system that appeared to reduce devil road kill. If shown to be successful, it could be extended Australia-wide.
Wildlife Rescue Line: 13 000 WIRES or 1300 094 737.