The study published June 5 in PLoS Computational Biology, explains how bats use echolocation for more than just spatial knowledge and it might also help explain how some bats travel at high speed, at night, in formation without interfering with each other.
The researchers first tested the ability of four greater mouse-eared M. myotis bats from Bulgaria (sorry, Dracula fans, not Romania) to distinguish between the echolocation calls of other bats. After observing that the bats learned to discriminate the voices of other bats after two to three weeks, they then programmed a computer model that reproduces the recognition behavior 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.
CITATION: Yovel Y, Melcon ML, Franz MO, Denzinger A, Schnitzler H-U (2009) The Voice of Bats: How Greater Mouse-eared Bats Recognize Individuals Based on Their Echolocation Calls. PLoS Comput Biol 5(6): e1000400. doi:10.1371/journal.pcbi.1000400