“Whoooo said that?”: responses of captive owls ( <i>Strigiformes</i> ) to the voices of familiar caregivers

Group-living is hypothesized to select for individual recognition, but territorial and cooperatively breeding species would also benefit from this ability, even with regard to heterospecifics. Some social species differentiate familiar human caregiver voices from the voices of unfamiliar humans but few non-domesticated, non-group-living species have been tested. We presented 21 captive owls ( strigiformes ) representing seven species with playbacks of unfamiliar and familiar human voices. We predicted that subjects would respond ( i.e ., head turns, peering, vocalizations and postural changes) differently to familiar compared to unfamiliar voices but that this response would depend on the nature of the relationship between the owls and their caregivers. The owls were slower to respond and increasingly likely to exhibit fearful postures across playback trials within sessions. However, owls were more likely but slower to respond to the voices of familiar caregivers the longer they had worked with them for. They were also faster to respond to the voices of those that performed aspects of their husbandry and those that rated their relationships with the owls more positively. Lastly, they were less likely to show fear when they heard the voices of their trainers compared to those of other familiar individuals and when the relationship was rated as more positive compared to less positive. These results suggest that owls in managed care are capable of recognizing individual caregiver voices, and even that they may encode aspects of their relationship along with the sound of the caregiver’s voice.