Mobbing Responses of Some Passerines to the Calls and Location of the Screech Owl
Abstract
Tests using 12 nest/roost locations of the Screech Owl (Otus asio) and 12 nonnest/non-roost locations in a five-county area of Piedmont North Carolina showed that passerine birds recognize the call of Screech Owls, associate an owl's call with its likely location, and remember the location. Passerines mobbed a speaker playing recordings of Screech Owl calls in non-nest/non-roost locations, but playbacks of calls stimulated orientation not to the speaker but to the nest/roost in known owl locations. In all nest/roost locations, the first bird to respond oriented to the owl cavity. The results suggest that a function of mobbing is to gain information about the predator. Mobbing may have evolved from the fight-flight conflict during encounters with predators into a social display communicating presence and location of a predator.
