A Never-Before-Seen Mimicry Trick Has Just Been Recorded in Buzzing Bats

Some bats use a trick that makes them sound more dangerous than they really are, by buzzing like hornets when they think they're in danger.

It is the first time that this behavior has been recorded in mammals, but it happens elsewhere in the animal kingdom, such as when the wings of moths are patterned to appear like the insect is a different, much more dangerous species.

The team behind the new study on bats says their findings yield an important insight into both evolutionary processes and the ways animals will try and defend themselves when cornered.

In Batesian mimicry, a non-armed species imitates an armed one to deter predators.

Imagine a bat that was seized but not killed by the predator. Buzzing may be enough to deceive the predator for a fraction of a second.

When the researchers handled animals that had been caught in nets, the greater mouse-eared bats made buzzing sounds. It seemed like a distress call, but it wasn't until years later that work began on the study.

The researchers compared the buzzing sounds of bats and stinging social hymenopteran insects to confirm their hunch.

They played the sounds to wild owls and owls raised in captivity. There was some consistency when it came to buzzing from both insects and bats, and to standard, non-buzzing bat sounds.

Owls reacted to hymenopteran and bat buzzes in the same way, by increasing the distance from the speaker, according to the researchers.

They approached the latter as expected from a non-mimetic vocalization produced by potential prey.

The owls who hadn't been raised in captivity showed the strongest adverse reaction to both bat and insect buzzing, as they were more knowledgeable about potential harms than owls bred in captivity.

When the acoustics were analyzed to show only sounds that owls can hear, the similarities to insects were more pronounced.

It is possible that bats and insects share a lot of the same spaces, but this kind of acoustic mimicry is rare, and it is interesting to see bats borrowing from another species.

It is somewhat surprising that owls represent the evolutionary pressure shaping acoustic behavior in bats in response to unpleasant experiences.

It is one of the many examples of the beauty of evolutionary processes.

Current Biology published the research.