Australia’s Cane Toad Problem: How the Fridge-Then-Freezer Technique and Tadpole Lures Offer a Solution
Cane toads have been a prevalent problem in Australia since they were first introduced in 1935. These warty amphibians were brought over in an attempt to control the sugarcane beetle population, but instead, they have become a significant pest themselves. They have spread across much of tropical and subtropical Australia, causing damage to native ecosystems and outcompeting native species for food and habitat.
For the past 75 years, Australians have been on a mission to eliminate these deadly invaders. And while there have been many heinous methods suggested for their elimination, there is now a humane way to both control their population and utilize their carcasses.
Cane toads (Rhinella marina) are a large amphibian native to Central and South America. They were introduced to Australia in 1935 in an attempt to control the sugarcane beetle. Unfortunately, the toads were not effective at controlling the beetles and instead became a significant pest themselves. They have since spread across much of tropical and subtropical Australia, damaging native ecosystems and outcompeting native species for food and habitat. Cane toads are considered an invasive species in Australia, an ecological disaster, and efforts are being made to control their population.
How to kill a cane toad humanely
The key to this new method is the “fridge-then-freezer” technique. Cane toads can be found seeking food in easily accessible areas such as parks and ovals at dusk. By catching them at this time, using nothing more than a bucket and a pair of gloves or a garbage pick-up stick, we can prevent nearly one billion tadpoles from entering the environment each year.
Here’s how it works: once caught, the toads should be placed in the bucket and then put in the fridge. This step is critical as it cools them down and induces torpor, a state similar to hibernation that involves a slowing of bodily functions. Australian researchers have discovered that toads cooled in the fridge for a few hours show no signs of pain when they are later frozen.
While freezing the toads may seem like the final step, it’s important to note that the fridge-then-freezer method also reduces the likelihood of encountering “zombie toads.” These are toads that wake up after being frozen because they were frozen too quickly and not cooled before being frozen.
The Science Behind Cane Toad Control: How Pheromones Can Make a Difference
But there’s more! The environmental benefits of this method don’t stop there. Researchers at the University of Sydney and the University of Queensland’s Institute of Molecular Bioscience have discovered a way to use the cane toad’s own toxin against them. They’ve found that when tadpoles hatch in rivers, streams, dams, or ponds, they are compelled to seek out and consume the eggs laid by other females. This is accomplished by following the scent of pheromones found in cane toad toxin.
By isolating pheromones from toxin glands harvested from dead toads, researchers can make tadpole lures that attract only cane toad tadpoles and not native species. This is a game-changer as it will allow us to control the population of cane toads without affecting native frogs or toads.
A local company is now commercializing these lures, and they are expected to go on sale in the first few months of this year. With this new method, we can control the population of cane toads in a humane and environmentally-friendly way. So, grab your bucket and gloves, and let’s get to work saving Australia’s native species!