02388nas a2200241   4500008004100000245010700041210006900148260001600217300001400233490000800247520168200255653001401937653001101951653001801962653001201980653001301992653001102005100002102016700001802037700002002055700001702075856005402092       2018                        eng d00aRavens adjust their antipredatory responses to con- and hetero-specific alarms to the perceived threat0 aRavens adjust their antipredatory responses to con and heterospe  cJan-08-2018  a609 - 6160 v1243 a<p>Heterospecific alarm calls are typically found in situations where multiple species have a common predator. In birds, they are particularly common in mixed mixed‐species flocks. In species with highly developed social and cognitive abilities like corvids, there is the potential for differential responses to heterospecific vs. conspecific calls according to the riskiness of the habitat. We tested the responses of free‐ranging ravens (Corvus corax) to conspecific alarm calls and compared them to heterospecific alarm calls of jackdaws (Corvus monedula). We observed the proportion of ravens leaving the feeding site after the con‐ or hetero‐specific playback was presented in a situation of low threat (wild boar&mdash;Sus scrofa enclosure) and high threat of predation (wolf&mdash;Canis lupus enclosure). We show that ravens responded to conspecific calls more intensively at the wolves than at the wild boar, but the response to conspecific calls was in both enclosures stronger than to the control (great tit&mdash;Parus major song). The response to the heterospecific alarm was also stronger in the wolves&rsquo; enclosure, but it did not differ from control in the wild boar enclosure. These findings suggest that ravens are aware of the meaning of the jackdaw alarm calls, but they respond to it only in a situation of high predatory threat (wolves are present). In the wild boar enclosure, the ravens probably consider jackdaws warning against some other predator, very probably harmless to ravens. This interpretation requires further testing, as both enclosures differ also in respect to other parameters like food quality and shelter availability.</p>
10aavoidance10acorvid10ahonest signal10ajackdaw10apredator10athreat1 aNácarová, Jana1 aVeselý, Petr1 aBugnyar, Thomas1 aTregenza, T.  uhttp://doi.wiley.com/10.1111/eth.2018.124.issue-8