Innate or learned acoustic recognition of avian predators in rodents?

Calls of avian predators potentially predict danger for murine rodents. Indeed, exposure of field-experienced rodents to owl calls induces defensive behavior suggesting that recognition of vocalizations of avian predators is innate. To address this hypothesis, we investigated whether laboratory-reared and predator-naive rodents (mice, gerbils, rats) express defensive behavior in response to calls of different avian predators but we observed no such defensive behavior. We then asked whether the calls of avian predators are faster or better learned as a danger-predicting cue than the calls of avian non-predators. All calls could be learned as danger-predicting cues, but we found no differences in the speed or strength of the learning. Taken together, our results suggest that there is no innate recognition of the calls of avian predators in murine rodents and that the recognition of the calls of avian predators observed in field-experienced rodents is acquired by learning.