Toad trappers mimic soul star
Female cane toads are attracted to ‘‘Barry White’’-style mating calls that could help sound the end of the pest, a Queensland study has found.
A James Cook University study mimicked the sound of cane toad mating calls and managed to catch 2000 toads across the Townsville campus and Orpheus Island off Ingham over a two-year period.
PhD candidate Ben Muller said the initial audio traps managed to capture only 20 per cent of females.
‘‘It is like any animal in the world – the female wants to pick the best mate. This is how toads do it – they pick their mates by the sound of their call,’’ he said.
‘‘[The traps] play a toad mating call and other toads are attracted to the call, and we trap them, and everyone is happy.
‘‘We worked out that we weren’t catching as many females as we wanted. We were catching 80 per cent males, which is fine, but we want to target females because they lay up to 30,000 eggs at a time, so if we remove one female it is better than removing one male.’’
Muller, with the help of his supervisor Lin Schwarzkopf, began tinkering with different combinations of volume, frequency and pulse rate to attract the largest amount of female cane toads.
He found that approximately 91 per cent of females were trapped using a low frequency tone and high pulse rate mating call.
‘‘The low frequency is representative of a large male toad, while the high pulse rate is representative of an energetic toad,’’ he said. ‘‘We are representing a large, energetic male with that call.’’
So what does the ‘‘attractive’’ male cane toad mating call sound like?
‘‘Barry White is probably the closest. He probably has the deepest voice that I can think of,’’ Muller said.
‘‘From a distance, it sounds like a generator or a car engine, but when you get closer it is kind of a trill sound, but it is quite low.’’
He said that while the audio traps were not capable of eradicating the entire cane toad population across Australia, they could go some way towards erasing smaller populations.
‘‘We can play it to attract toads and remove them, so it could be a potential control strategy.’’