The sparrow and the hawk: aggressive signaling under risk of predation

Çağlar Akçay, Allie Clay, S. Elizabeth Campbell and Michael D. Beecher

Behavioral Ecology, 2016, vol. 27, issue 2, 601-607

Abstract: Eavesdropping by predators imposes a major cost on signalers, which in turn have evolved a number of strategies to deal with this cost. These strategies however, have not been well studied in the context of aggressive signaling. Here, we report an experiment on male song sparrows (Melospiza melodia) in which we experimentally increased the perceived predation risk by playing Cooper’s hawk (Accipiter cooperi) calls or control Northern flicker (Colaptes auratus) calls in the midst of a simulated conspecific territorial intrusion and assessed the change in signaling strategies. We found that song sparrows clearly discriminated between the hawk call and the flicker call. Specifically, subjects decreased number of songs and wing wave displays (a visual signal of aggressive intent) and increased alarm calling during the hawk playback. However, the change in signaling behaviors did not persist when the simulated intruder resumed his challenge, despite the fact that the subjects were still alarmed as indicated by high rates of alarm calling. Additionally, we found no evidence for the eavesdropping avoidance hypothesis as an explanation for the low amplitude of soft song, the most reliable signal of aggression in this species. These results suggest that male song sparrows flexibly adjust their signaling effort in response to both the predation risk and the need to defend their territory against an intruder.

Date: 2016
References: View complete reference list from CitEc
Citations:

Downloads: (external link)
http://hdl.handle.net/10.1093/beheco/arv196 (application/pdf)
Access to full text is restricted to subscribers.

Related works:
This item may be available elsewhere in EconPapers: Search for items with the same title.

Export reference: BibTeX RIS (EndNote, ProCite, RefMan) HTML/Text

Persistent link: https://EconPapers.repec.org/RePEc:oup:beheco:v:27:y:2016:i:2:p:601-607.

Ordering information: This journal article can be ordered from
https://academic.oup.com/journals

Access Statistics for this article

Behavioral Ecology is currently edited by Louise Barrett

More articles in Behavioral Ecology from International Society for Behavioral Ecology Oxford University Press, Great Clarendon Street, Oxford OX2 6DP, UK.
Bibliographic data for series maintained by Oxford University Press ().