For those who are keeping their finger on the pulse of conservation ecology research in Australia, you’d be forgiven for thinking the newspaper article below might have been written in the past 6 months.
The 1953 report outlines the fallout from the release of the myxomatosis virus, and demonstrates the profound complexities in Australia’s ecosystem – in particular, the impact that prey switching probably had on small mammal populations when foxes ran low on their once plentiful food source, the European rabbit.
The article is a profound reminder of the fact that we’ve known for many decades about some of the big-impact ecological interactions that impact Australia’s wildlife. And whilst we’ve spent a lot of time on refining these theories of species-interactions in the 65 years since the article was written, this has not resulted in any significant shift in the management intervention we use to combat foxes.
Baiting, shooting and trapping
These traditional management responses should be considered a reactionary response to foxes, rather than a tactical response. They also rely on a vast quantity of people power. And this people power translates into a vast quantity of money. About $16 million dollars each and every year in management costs are spent on foxes – but with ongoing economic and environmental losses estimated at $207.5 million dollars per year. So should we be trying to look at the management of foxes with fresh perspective?
Professor Mike Letnic, from the University of NSW provided a fantastic summary of the situation in Daniel Hunter’s documentary, ‘Battle in the Bush’. “We understand that these invasive predators like foxes and cats have these devastating effects on our ecosystems. And our answer to it has been to poison the continent. In fact we’re poisoning vast areas of the continent, with the intention of killing foxes and cats. This works, often, and brings back our populations of native animals – but it doesn’t always. In many instances native animals get killed by the poison. But the other thing is, we have to poison for ever. For ever and ever and ever using that strategy. And it’s a really risky strategy. Governments are increasingly conservative about financing biodiversity conservation programs, and if they can’t get funding for poison – then there’ll be no more poison”.
And it’s what we see on the ground. Rewilding Australia itself reluctantly undertakes fox control using 1080 baits and shooting to protect various threatened species that lie in the Critical Weight Range for animals that can be snacked on by foxes (~35g to 5.5kg). It’s not a great strategy – it relies on long-term financial backing, a supportive local community, reasonable weather conditions (as baits rapidly degrade in wet weather and contract shooters seem to have a significant aversion to rain) and as soon as the baiting and shooting stops, the foxes march back on in. And as Professor Letnic stated, Governments are increasingly conservative with funding for baiting programs (Rewilding Australia has not been able to secure a single Government grant for fox baiting in the past 12 months).
So what do we do? Should we just keep scrounging around for money to keep these programs going for the next thousand years, or do we look for longer-term strategies?
Species Interactions the Key
A renewed focus on species interactions is a methodology that might allow us reduce our reliance on baiting, shooting and trapping over time. But we’ll never know if we don’t actively pursue research into these areas.
How species interact within their own species (intraspecific relationships) as well as how species interact with other species (interspecific relationships) is how we need to start thinking, when developing solutions to the problems of foxes and cats, which continue to push many of Australia’s species towards extinction.
Can we make native wildlife be a little more wary of our feral pests? Predator avoidance is certainly an exciting area of research. An interesting example is the recent translocation of northern quolls to Indian island, off Darwin in the Northern Territory to determine if quolls with an aversion to the taste of toxic cane toads can be bred.
Could reintroducing our own native predators provide an interaction with foxes and cats that results in overall net benefits for our Critical Weight Range species? A prime candidate species is the Tassie devil (which, it should be noted, could be just as easily be referred to as the ‘Aussie devil’). The only reason this hasn’t yet happened is because of the noxious mix of political resistance, a lack of political will, and public servants beholden to the ‘don’t rock the boat’ mantra.
Gene Drive Technology
In terms of intraspecific relationships, Gene Drive technology is a rapidly developing concept offering probably the best technological solution to Australia’s fox and cat crisis. The technology could be used to engineer animals that produce only male offspring. These males will in turn mate with females in the wild, and only produce male offspring. These fully fertile offspring will drive this character through the population and eventually cause it to crash. Eventually the wild population will be eliminated through lack of females. No animal cruelty, no toxins and no risk of spreading to other species, as the genes are only spread by copulation.
But why haven’t we quite got there yet? Professor John Knight from New Zealand’s University of Otago explained recently to the Otago Daily Times. Applying Gene Drive Technology to pest animal species “has never been funded, blocked by anti-GM nay-sayers…and deemed ‘too risky’, in terms of upsetting people who feared genetic engineering. Never mind the risk of doing nothing, or of dropping 90% of the world’s production of 1080 poison out of aircraft — and hoping” (in reference to New Zealand’s reliance on 1080 to control stoats and weasels).
Reaching an endpoint seems unlikely to happen if we rely on poisons, diseases, traps, shooting, or other conventional methods. Disease-resistant, bait-shy, trap-shy, animals will always survive and outbreed those that succumb.
Darwin coined the term ‘survival of the fittest’ to explain this.
Funding complex and emotive research is always more difficult than simply throwing money at a conventional practice that’s largely accepted by the community. But it’s up to all of us to ensure innovative solutions that will stand the test of time, and will allow us to move beyond what is currently an unwinnable war on foxes and cats, start receiving a little more attention.