How bats distinguish between the calls of their own and different species

Scientists of the Max Planck Institute for Ornithology in Seewiesen have found that bats can distinguish between the calls of their own and different species with their echolocation calls.

As opposed to bird song or the human voice, echolocation calls are primarily used for spatial orientation and search for food and not for communication. Bat species with similar ecological requirements use similar echolocation calls.

However, it was recently shown that bats are able to distinguish conspecifics by their individual calls, somewhat similar to how humans can recognize others by voice.

Now, Maike Schuchmann and Bjorn Siemers of the Max Planck Institute for Ornithology in Seewiesen have been able to prove that echolocation calls carry more information than assumed.

As humans are able to recognize different languages, bats can not only distinguish their own calls from calls of other species, but also differentiate between different species, even if there is an overlap in the call frequency bands.

The scientists set up behavioral experiments with two horseshoe bat species in Bulgaria. They played echolocation calls of the bats’ own species or calls of three different species through ultrasonic loudspeakers and analysed the animals’ reaction.

Both bat species hardly made a mistake in their distinction, neither between own and foreign calls nor foreign and foreign calls.

“Discrimination was however easier for the bats when the call frequency bands were clearly separated from their own”, said Maike Schuchmann, first author of the study.

The study has been published in journal The American Naturalist.