Genetic back-burning, protecting native fauna from Cane Toads.
It jumped through the leaf litter, noisily crashing towards me. I was startled, a thumping big Cane Toad out to get me!
At least thats what I though as a 10 year old meeting my first Cane Toad at the fabulous oasis that is Lawn Hill National Park. In my defence it was late evening and I’d not met one of these beastly creatures before. What else was I to think?
Apparently this toad was not pursuing me, it was just on its way to a campground light waiting for its next meal to fall from the sky. Like me it was the first time these toads had been to Lawn Hill, little did I know it but I was witnessing the advance front of a biological invasion.
Avante garde Toads
Yes, these truly were avant-garde toads, literally the advance front pushing the known boundaries, driving radical ecological change. What surprised me most was how fast they moved, growing up in Melbourne I was under the impression that these were a slow sluggish beast.
As many will know, the advance front of Cane Toads is evolving rapidly. They have longer legs, jump further and travel more rapidly than their ancestors introduced in the early 1930s. But, at their original release site in Innisfail toads are a slow sluggish beast……more on that later.
Lawn Hill gorge via Wikicommons
Cane toads have advanced considerably since the time I first met them in 1985, they’re now travelling northern Australia at about 50 kilometres per year, and they’re speeding up as the years go by. They’ve yet to reach their full potential range with some estimates putting their ultimate southern range in Western Australia somewhere near Geraldton.
Winners and Losers
The impact of toads across northern Australia has been variable. It hasn’t been a complete ecological disaster but some species have been hit harder than others. Predators such as the Northern Quoll and Mertens Water Monitor have declined rapidly. Not solely due to toads but certainly they play a role.
Northern Quoll via Flickr
Some birds and turtles whose eggs were consumed by larger goannas have increased because their predators have declined. Many goannas being poised by toads which pump out a lethal toxin from a gland on their back when harassed.
Science Innovation steps in…..
But an innovative idea by University for Melbournes Ben Phillips might just be able to stop the advance of toads. Ben has suggested that the release of Cane Toads from the slow sluggish part of their range should be considered. These toads released at the edge of the advance front could result in slow sluggish toads genetically overwhelming the avant-garde toads, effectively out breeding the fast movers and stopping their advance.
But this must occur at a very strategic location.
Source; Ecography, vol.31, pp.423-434.
It turns out that there is a geographic arcilles heal in the advance of Cane Toads. A long stretch of the Pilbara is without water with the exception of around 70 artificial watering points on outback Stations. Its thought that with a few adjustments of these watering sites they will be unsuitable for toads. Combined with the realise of slow sluggish toads just before this location could dramatically reduce there potential spread.
Ben has termed this idea ‘genetic back-burn’, this phrase being inspired by the process used by indigenous people for thousands of years and more recently by land managers.
Its a risky proposal and one that may raise the eye brow of the public averse to unfamiliar ideas. What is certain is that toads will make a swift advance south over the next twenty years if left unabated.
What do we have to loose?
No discussion about Cane Toads is complete without reference to this classic insight into Northern Queensland culture, Cane Toads, An Unnatural History enjoy!