Latest news with #GraemeSawyer
ABC News
03-06-2025
- Health
- ABC News
Darwin teams milk cane toad toxin for trap bait to protect native wildlife
Milky liquid squeezed from the glands of cane toads could be key to controlling the invasive pests in Australia. BiodiversityWatch coordinator Graeme Sawyer is working with fellow Top End toad busters to trap tadpoles and adult toads, minimising populations to take the pressure off iconic native species. Mr Sawyer says one of the "really big problems in the Northern Territory since toads arrived" is that potentially billions of the invasive pests compete with other wildlife to access the exact same food sources. But by using the amphibian's own toxic milk to attract them into funnel-shaped tadpole traps, the success of cane toad breeding is restricted. "If you get rid of the toads, it leaves the food supply for a whole range of native animals," Mr Sawyer says. Milking the amphibian's parotoid gland extracts cane toad toxin, which is then placed inside the underwater traps. A gentle squeeze to the gland is all it takes to secrete the liquid, in a process that resembles pimple popping. With further planning and a strategic approach, Mr Sawyer says the traps "could probably wipe those tadpoles out of these waterways completely". The strategy is safe for natives too, since only cane toads and some feral fish associate the smell with food. Unlaid eggs carried by female cane toads are laced with the toxin too, so they also work "very well" in traps. Mr Sawyer has been collaborating with the City of Darwin to remove 900 cane toads from East Point and another 900 from Jingili Water Gardens this year alone. The council's environment and climate change coordinator Emma Smith says his "wealth of knowledge" has been vital. In return, Mr Sawyer says he has been impressed by the council's efforts, but believes more action could spread the success even further. He points to a trial of traps at the Marrara Golf Course which successfully eliminated "every single tadpole in a couple of days" from the facility's ponds two years ago. "One of the traps took out 16,000 tadpoles in one night," he says. "But to do it on a broader scale is something that needs some serious attention. Ms Smith says cane toad busts first started in Darwin's inner-north "biodiversity asset" of East Point, and this year expanded into the Jingili Water Gardens, which he called "cane toad heaven". He says the shallow fresh water attracts breeding toads, which is a hazard for other species living there. The yellow-spotted monitor can mistake juvenile cane toads for food, which can kill the threatened lizards when the toads are ingested. Ms Smith says the monitor — along with the iconic blue-tongue and frilled-neck lizards — "used to be everywhere" in Darwin, but local reptile populations had "declined dramatically since cane toads arrived". However, toad busting efforts seem to be working, with the number being collected also starting to trend downwards. Mr Sawyer is encouraging the public to get involved, describing the trapping strategy as "deadset easy". Teams in Queensland have developed traps with artificial bait tablets, which can be purchased "if you're not up to milking cane toads yourself". And if you find eggs in a pond, they can also be used in the traps. "You make a box, or you can buy a commercial one, put that in the water body and drop these baits in," Mr Sawyer says. "Every other day you come along and tip all the tadpoles into a net, then euthanise them." Freezing cane toads is the most humane way to do it, but tadpoles will die without water — so leaving them to dry on the ground also works. Ms Smith advises putting adult toads in the fridge for 12 hours first, then the freezer for 12 hours, and says the dead toads can be buried or disposed of via compost bins. She says she'd like to see more community education around cane toads, because the public "could really help" if they understand how to spot and kill the pests, pointing to a February bust where 322 were caught in a matter of hours. Mr Sawyer says it's important for NT residents to do their bit. "Anything you can do to keep toad numbers as low as possible is helping the other native wildlife." To keep toads out of pools and ponds, Mr Sawyer recommends constructing a small barrier with a smooth material — not a fine mesh like chicken wire. Native tree frogs have padded toes, so they can scale windows with ease, but cane toads don't have the same pads so can only climb surfaces that have texture to grip onto.
ABC News
03-06-2025
- General
- ABC News
How to identify cane toad tadpoles
BiodiversityWatch's Graeme Sawyer outlines the key features, including colour and tail length, that can help identify a cane toad tadpole.
