Roles of Acoustic Social Communication in the Lives of Bats

Abstract

The gregarious nature of bats combined with the diversity of ecology, behavior, and social organization among bat species make them well suited for studying communication systems. Recent research in this area has revealed several themes. Males frequently produce social calls and/or songs to attract females for mating purposes. Specific social calls are often produced during aggressive encounters, such as when bats are defending a feeding area or males are competing for access to females. Contact calls help to maintain group cohesion and have been reported in several situations between adults and young bats, but also among roost mates. Contact calls often encode information about the identity of the sender, permitting discrimination of an individual’s own offspring, parent, or group member from other signalers in the environment. Distress calls are regularly produced when animals are attacked or threatened. While echolocation calls have been considered separate from social calls, signals used in orientation also encode information about the transmitter that is readily available to other individuals. Bats often are particularly attracted to the feeding buzzes of conspecifics, which are emitted when an individual attempts to capture prey. Eavesdropping on echolocation calls is a primary mechanism by which some bats locate roosts used by other bats. Personal information, including species, sex, age, body condition, reproductive condition, group identity and/or individual identity can be encoded into echolocation calls. As in other mammals, acoustic signals in bats often are accompanied by olfactory and/or visual displays, further enriching the communication repertoires of bats.