Alarming features: Birds use specific acoustic properties to identify heterospecific alarm calls

Date

2013

Authors

Fallow, Pamela
Pitcher, Benjamin James
Magrath, Robert D

Journal Title

Journal ISSN

Volume Title

Publisher

Royal Society of London

Abstract

Vertebrates that eavesdrop on heterospecific alarm calls must distinguish alarms from sounds that can safely be ignored, but the mechanisms for identifying heterospecific alarm calls are poorly understood. While vertebrates learn to identify heterospecific alarms through experience, some can also respond to unfamiliar alarm calls that are acoustically similar to conspecific alarm calls. We used synthetic calls to test the role of specific acoustic properties in alarm call identification by superb fairy-wrens, Malurus cyaneus. Individuals fled more often in response to synthetic calls with peak frequencies closer to those of conspecific calls, even if other acoustic features were dissimilar to that of fairy-wren calls. Further, they then spent more time in cover following calls that had both peak frequencies and frequency modulation rates closer to natural fairy-wren means. Thus, fairy-wrens use similarity in specific acoustic properties to identify alarms and adjust a two-stage antipredator response. Our study reveals how birds respond to heterospecific alarm calls without experience, and, together with previous work using playback of natural calls, shows that both acoustic similarity and learning are important for interspecific eavesdropping. More generally, this study reconciles contrasting views on the importance of alarm signal structure and learning in recognition of heterospecific alarms.

Description

Keywords

Keywords: acoustic property; alarm signal; antipredator defense; frequency analysis; identification method; passerine; risk assessment; Aves; Malurus cyaneus; Troglodytinae; Vertebrata Acoustic properties; Alarm call; Eavesdropping; Malurus cyaneus; Risk assessment; Superb fairy-wren

Citation

Source

Proceedings of the Royal Society of London Series B: Biological Sciences

Type

Journal article

Book Title

Entity type

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License Rights

Restricted until

2037-12-31