Impressionists are a mainstay of British comedy, with the likes of Rory Bremner and Alistair MacGowan uncannily mimicking the voices of celebrities and politicians. Now, biologists have found that tiger moths impersonate each other too, and they do so to avoid the jaws of bats.
Some creatures like starlings and lyrebirds are accomplished impersonators but until now, we only had anecdotal evidence that animals mimic each others’ sounds for defence. Some harmless droneflies may sound like stinging honeybees, while burrowing owls deter predators from their burrows by mimicking the distinctive warning noises of deadly rattlesnakes.
In tiger moths, Jesse Barber and William Conner from Wake Forest University, North Carolina, have found the first hard evidence of acoustic mimicry in animals. Tiger moths are hunted by bats, which use ultrasonic clicks – echolocation – to home in for the kill.
Moths are tuned into the sounds of these clicks and respond with their own ultrasonic sounds, created by vibrating special membranes called ‘tymbals’ on their abdomens (see a Quicktime video of the tymbals in action). The sounds are multi-purpose – they may startle the bats, or jam their transmissions. But according to Barber and Conner, they also carry a message – they say “Don’t eat me, I won’t taste very nice.”