STIMULI ELICITING DISTRESS CALLS IN ADULT PASSERINES AND RESPONSE OF PREDATORS AND BIRDS TO THEIR BROADCAST

摘要: This study examined the response of birds and captive predators to broadcast distress calls effect different stimuli on elicitation ofthese calls. In doing so, this tested two hypotheses about why adult passerines should call when physically constrained: are designed 1) attract attention, or 2) startle predator into releasing caller. Birds often responded both interspecific intraspecific by approaching sound source, but they rarely mobbed engaged in any behavior that would aid caller escaping. The playback a had little most opossums (Didelphis marsupialis) raccoons (Procyon lotor) which were attacking caged starling (Slurnus vulgaris). However, startled one opossum provoked other more severe attack. only called constrained. All passerine species tested, except brown-headed cowbirds (Molothrus ater), emitted calls, no did every individual call. Distress usually short duration, interrupted periods silence, paired with struggling behavior. likely held limbs rather than body neck, moved, viewing rapidly object. These results indicate function for is predator, functions also likely. My support hypothesis approach acquire information has captured