The westward march of the cane toad continues and the sad but inevitable cross into Western Australia has now happened. A couple of years ago, I did a report for the then Minister for the Environment and Conservation in WA and concluded, like most people, that it was unavoidable that toads would eventually move into Western Australia (get a copy of the report here).
While it was predictable, it is still really sad as a lot of wildlife will die as they encounter toads. But the devastation is probably not as bad as we once thought. Professor Rick Shine's team from the University of Sydney have continued to study the impact of toads. Importantly, they've been doing an inventory of potential impacts by testing wildlife from the Kimberley at the University's Fogg Dam Research Centre in the Northern Territory. They've done this work with Dr. Dave Pearson and others from the WA Department of Environment and Conservation.
As I understand the Sydney Uni/WA DEC team's results, they tend to give us cause for hope. Most wildlife will adapt. Some might never touch toads, others evolve and others learn. It's one of those "good news/bad news" type of situations you hear of in doctor jokes - you'd rather you weren't faced with either possibility.
I noted in the media release from WA that it ended like a lot of toad releases have over the years - with the hope that research will uncover a biological control agent. CSIRO gave up many years ago looking for one in South American and a year ago they finished up trying to develop a genetically altered one. Few options are on the books. Again, Shine's lab is the closest to any solution. They've identified a little lungworm that knocks the toads about. Basically, they are like a smoker - they can't run as far or as fast and they die earlier. The toads on the "western front" have out run the parasite and could be very susceptible to it. Moreover, the parasite appears to have accompanied the toads to Australia and thus are probably quite limited in their genetics - perhaps they could be "refreshed" from the toad's native range in South America.
Biological control is hard work and controversial. In vertebrates, myxoma virus and rabbit haemorrhagic disease virus (calicivirus) are basically it. It would be a matter of the risk/reward for such a venture.
I think we need to turn to those species that are going to do badly with the toads coming their way. We know up to half the freshwater crocodiles can be killed by toads. What of the "pygmy" population on Bullo River Station? It would be good to see them protected.