Bats can use the characteristics of other bats' voices to recognize each other, according to a study by researchers from the University of Tuebingen, Germany and the University of Applied Sciences in Konstanz, Germany. The study explains how bats use echolocation for more than just spatial knowledge.

The researchers first tested the ability of four greater mouse-eared bats to distinguish between the echolocation calls of other bats. After observing that the bats learned to discriminate the voices of other bats, they then programmed a computer model that reproduces the recognition behaviour of the bats. Analysis of the model suggests that the spectral energy distribution in the signals contains individual-specific information that allows one bat to recognize another.

Animals must recognize each other in order to engage in social behaviour. Vocal communication signals are helpful for recognizing individuals, especially in nocturnal organisms such as bats. Little is known about how bats perform strenuous social tasks, such as remaining in a group when flying at high speeds in darkness, or avoiding interference between echolocation calls. The finding that bats can recognize other bats within their own species based on their echolocation calls may therefore have some significant implications.

This work was funded by SFB 550, by the Graduiertenkolleg Neurobiologie. It was supported in part by the IST Program of the European Community, under the PASCAL network of excellence, IST-2002-506778. This work was also supported by the human resources and mobility activity Marie Curie host fellowships for early stage research training under contract MEST-CT-2004-504321 PERACT by the European Union. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.