6533b86ffe1ef96bd12ce31e

RESEARCH PRODUCT

Asymmetrical interspecific communication in avian mixed species colonies

subject

description

Sympatric species derive benefits by attending to information conveyed by heterospecifics. We previously reported reduced vigilance among jackdaws (Corvus monedula) and lesser kestrels (Falco numanni) residing in mixed species colonies and conducted the present study to test for interspecific communication of threat associated with European magpies (Pica pica) as nest predators. After quantifying structural differences in jackdaw and lesser kestrel calls relative to European magpie versus non-predator models, we played back calls of jackdaws and lesser kestrels representative of the different model types to test whether receivers perceive threat-related variation in either conspecific or heterospecific calls. We detected differential behavioural responses to call playbacks, with both jackdaws and lesser kestrels increasing vigilance and alarm calling in response to magpie elicited jackdaw calls, but not to other call types. Taken together, our results suggest that jackdaw, but not lesser kestrel vocalizations, communicate enhanced threat associated with European magpies as possible nest predators. This interspecific alarm communication benefits both jackdaws and lesser kestrels, and at least in part, explains asymmetric responses of jackdaws and lesser kestrels to magpies attending mixed species colonies in nature.