Have you ever seen a toad fly? It’s not an uncommon sight in the North of Australia. Cane toad golf is something like a national sport in these regions. That tells a great deal about the love Australians bear these animals. Why so much hate? Because cane toads are like the evil aliens invading a foreign planet and killing its inhabitants.
Cane toads are an invasive species. Originally from Central and South America, the species was first introduced in Australia in 1935 as a mean to control the pests destroying sugar cane plantations. Since then, cane toads have been thriving in the tropical climate of Australia to the detriment of native animals. Cane toads produce toxins that are fatal to Australian predators which have not evolved alongside the cane toads and consequently haven’t learnt they don’t make a good meal or haven’t evolved a resistance to their toxins. But what makes cane toads nocive to Australian fauna might hold the key to rid the island of these amphibians.
The life of a cane toad tadpole is a harsh one. Competition between tadpoles is fierce so the less fellow tadpoles you have, the better you’ll fare. Which means cane toad tadpoles look for eggs of their own species and eat them. Researchers extracted different molecules from cane toad eggs and tested which ones attracted the tadpoles to the eggs. The same toxins produced by adult toads to deter predators were responsible for driving the tadpoles towards the eggs.
Using toxins as bait for traps the scientists managed to capture in a few days most of the cane toad tadpole population of ponds in the wild. What’s more with this technique other animals such as fish and insects were rarely caught as well as tadpoles of native species as they are repelled by the toxins.
Toxin-baited traps could be an efficient and easy method to eliminate the Australian cane toad population without causing much damage to the native fauna. Australians might soon have to find another sport to play.
Crossland MR, Haramura T, Salim AA, Capon RJ, Shine R (2012). Exploiting intraspecific competitive mechanisms to control invasive cane toads (Rhinella marina). Proceedings of the Royal Society B, 279, 3436-3442 DOI: 10.1098/rspb.2012.0821