Volume 99, January 2015, Pages 33–42
With whom to dine? Ravens' responses to food-associated calls depend on individual characteristics of the caller
- Open Access funded by Austrian Science Fund (FWF)
- Under a Creative Commons license
Open Access
Highlights
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- Wild ravens were tested for their ability to discriminate food-associated calls.
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- Calls of familiar and unfamiliar males and females were used.
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- Ravens selectively approached speakers playing calls of familiar females.
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- Ravens considered relative rank by preferentially approaching lower-ranking callers.
Upon discovering food, common ravens, Corvus corax,
produce far-reaching ‘haa’ calls or yells, which are individually
distinct and signal food availability to conspecifics. Here, we
investigated whether ravens respond differently to ‘haa’ calls of known
and unknown individuals. In a paired playback design, we tested
responses to ‘haa’ call sequences in a group containing individually
marked free-ranging ravens. We simultaneously played call sequences of a
male and a female raven in two different locations and varied
familiarity (known or unknown to the local group). Ravens responded
strongest to dyads containing familiar females, performing more scan
flights above and by perching in trees near the respective speaker.
Acoustic analysis of the calls used as stimuli showed no sex-, age- or
familiarity-specific acoustic cues, but highly significant
classification results at the individual level. Taken together, our
findings indicate that ravens respond to individual characteristics in
‘haa’ calls, and choose whom to approach for feeding, i.e. join social
allies and avoid dominant conspecifics. This is the first study to
investigate responses to ‘haa’ calls under natural conditions in a wild
population containing individually marked ravens.
