NATURAL SOLUTIONS
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another biological control that got out of control... the
cane toads are a good example of why you shouldn’t
do it,” he says.Restricting access to water
Cane toads mate in water. So keeping them away from
water would stop them reproducing. Of course, this is
easier said than done.
“In parts of Australia there’s so much water that it’s not
going to work,” Capon says. “And in urban areas it’s very
hard to put barriers around every water possibility...
they’re very opportunistic; they’ll breed in a puddle.”
Where it might work is in arid areas of Australia,
where bodies of water are largely man-made and few
and far between. It can also work in your backyard:
Toadwatch, a volunteer project in Darwin, recommends
putting a 50cm high smooth fence around a pond –
toads can climb wire fencing but not a material
such as weed matting.
Swimming pools are generally toad free, because
toads like to breed in the shallows.Taste aversion
Teaching predators that toads are bad might save
their lives. The invasion front is led by large toads big
enough to kill a quoll or crocodile straight away, so
researchers have been looking into releasing junior
toads ahead of the frontline.
The idea is that they’re just big enough to give
predators a bellyache, and put them off toads for life.
“Research has shown that exposing predators to
small toads immediately prior to the arrival of the
main toad invasion massively increases resilience
of the predators involved,” Shine says.Trapping tadpoles
One of the most exciting developments in the war on
cane toads is tadpole trapping. Cane toad tadpoles like
to eat eggs laid by other cane toads – and can find
them even in the murkiest waters, thanks to a chemical
being emitted by the eggs. Capon and his team have
found a way to produce this chemical and attach it
to a bait, which is placed in a trap.
In just a few hours you can collect up to 45,000
tadpoles in a single trap, Capon says.
As part of a citizen science and research project,
these baits are being made available for free, and are
being used by hundreds of organisations as well as
individuals (see ‘The Cane Toad Challenge’ for how
to get involved). It’s no silver bullet, Capon says, but
it could make a difference.
“It’s not going to get rid of toads in Australia,” he
says. “There are just too many of them, and traps
only work in places where there are people. The goal
is to provide another tool for groups that are already
picking up adults. If you take out tadpoles and adults,
there’s a better chance you’re going to have fewer
toads over time.”Top left: Cane toad tadpoles. Top right: A semi-submerged
cane toad tadpole trap. Above: Captured tadpoles.If you wanttogetinvolvedintheCane Toad
Challenge and trap some tadpoles, go to
imb.uq.edu.au/canetoadchallenge and look
for an affiliate group near you that can
provide you with the BufoTab baits, free
of charge.
You’ll need to build your own trap, but it’s
pretty simple: a tried-and-tested design is a
plastic crate with holes drilled in the sides
and two funnels inserted, with the wide end
of the funnels facing outwards.
You can download a Cane Toad Challenge
app and record your cane toad encounters
to help the research program.Challenge
THE CANE TOAD
PHOTOS: BEN DONNELLY