Ibis have learnt how to stress and wash cane toads

Tweet

I wrote once about cane toads. These were introduced to Queensland years back to combat a particular beetle that was causing havoc in sugar-cane plantations. Unfortunately, when the cane toad ran out of beetles, or even before, it went touring right across the top end of Australia and is now heading down the Western Australian coast. The toad has also caused the near-extinction of some of our native creatures, due to a toxin-filled parotid gland just behind the head. Interestingly, some native carnivorous birds and animals have found ways to safely kill and eat the toads. The latest to come to the attention of conservationists is the ‘stress and wash’ method employed by ibis. The ibis pick up the toads and flick them about. The defence mechanism of the toads comes into play and they release their toxins. The ibis – and I love this bit – then take the toads down to the creek and ‘wash’ them by swishing them through the water. This is a learned behaviour but is now being observed in multiple different regions. It seems the toxin isn’t particularly dangerous to birds. Some have learnt to avoid the shoulder glands and will flip the toad over to expose the softer underbelly. Gradually, our native species are learning to deal with this odious pest. The photo is of straw-necked ibis on our farmlet in Donnybrook.