Interindividual communication by bats via echolocation

The majority of over 1400 species of bats produce echolocation calls of diverse designs as a means of obtaining information about their surroundings, including the presence of prey. These calls also have the potential to contain information about the caller that can be used by other bats. We review the evidence for information transfer from echolocating bats to intended or unintended conspecifics and heterospecifics. Analysis of call structure and playback experiments on over 50 species in 11 families demonstrate that information regarding the species, population, sex, age, size, and individual identity of the caller is often contained within the calls, and in some cases can be recognized and used by other individuals. Intentional or unintentional (eavesdropping) communication occurs in feeding and roosting situations, as well as between individuals in social interactions such as in mate choice and between mothers and young. We also assess limitations of the research to date and suggest avenues for future research.