Australasian Science: Australia's authority on science since 1938

Scientists Produce a Hit Love Song for Toads

Researchers say they now know exactly what makes horny cane toads boogie – and the toad tune could help sound the death knell for the pests.

PhD student Ben Muller of James Cook University placed cane toad “audio traps” with differing characteristics at various sites in the Townsville region. “We varied the sound they were playing to have different combinations of volume, frequency and pulse rate,” he explained.

The team was particularly interested in attracting female reproductive toads. “A female cane toad may lay upwards of 20,000 eggs per clutch, so removing a single female with eggs from the population is more effective for control than removing a single male,” Muller said.

While male cane toads didn’t seem to care what variation of volume, frequency and pulse rate were used, female toads were much choosier. “We found we could manipulate the proportion of females, and reproductive females, that we trapped by changing the calls used as lures.”

The team found that approximately 91% of the females trapped using a loud, low frequency tone with a high pulse rate were reproductive. “We think that low frequency calls indicate to female toads that they are hearing a large-bodied male, and the high pulse rate means the male making the call has high energy reserves. These things combine to make them believe they have found a good breeding partner,” Muller said.

While this finding may help suppress toad numbers, Muller said it was not a silver bullet. “Large-scale eradication of cane toads from mainland Australia using traps is probably not possible; however, eradication of island populations could be achievable if the trapping regime was correctly designed and implemented,” he said.

The research will be used by Animal Control Technologies Australia to help create a commercial trap.