Personality influences alarm calling behaviour in song sparrows

Abstract

Alarm calls are a communication system in which the interests of senders and receivers often overlap, such that there may be little benefit to deception for senders, and yet, the potential cost of ignoring an alarm call can lead to a high number of false alarms. Increased frequency of false alarms may also be influenced by variation in personality traits such as boldness, which underlie all responses to dangerous or threatening situations. In this study, we investigated alarm calls in song sparrows (Melospiza melodia), and found a behavioural syndrome linking territorial aggression and boldness, such that more aggressive males respond more strongly to both conspecific and heterospecific alarm calls. In addition, those males that respond more strongly are also more likely to produce more alarm calls in response to playback. These results suggest that the strength of response to an alarm call by an individual could result from both the information in the signal and the personality of the receiver, and that the information in the signal may be influenced by the personality of the sender.