title: Correlated evolution between hearing sensitivity and social calls in bats.
abstract: Echolocating bats are auditory specialists, with exquisite hearing that spans several octaves. In the ultrasonic range, bat audiograms typically show highest sensitivity in the spectral region of their species-specific echolocation calls. Well-developed hearing in the audible range has been commonly attributed to a need to detect sounds produced by prey. However, bat pups often emit isolation calls with low-frequency components that facilitate mother-young reunions. In this study, we examine whether low-frequency hearing in bats exhibits correlated evolution with (i) body size; (ii) high-frequency hearing sensitivity or (iii) pup isolation call frequency. Using published audiograms, we found that low-frequency hearing sensitivity is not dependent on body size but is related to high-frequency hearing. After controlling for high-frequency hearing, we found that low-frequency hearing exhibits correlated evolution with isolation call frequency. We infer that detection and discrimination of isolation calls have favoured enhanced low-frequency hearing because accurate parental investment is critical: bats have low reproductive rates, non-volant altricial young and must often identify their pups within large crèches.
authors.affiliation: Department of Biology, University of Maryland, College Park, MD 20742, USA. kbohn@mail.utexas.edu
authors.forename: Kirsten M
authors.initials: KM
authors.lastname: Bohn
authors.forename: Cynthia F
authors.initials: CF
authors.lastname: Moss
authors.forename: Gerald S
authors.initials: GS
authors.lastname: Wilkinson
mesh_terms: D000818:Animals; D005075:Biological Evolution; D049628:Body Size / Q000502:physiology; D002685:Chiroptera / Q000502:physiology*; D004455:Echolocation / Q000502:physiology; D006309:Hearing / Q000502:physiology*; D010802:Phylogeny; D012919:Social Behavior; D013045:Species Specificity; D014828:Vocalization, Animal / Q000502:physiology*