An experimental study of feeding, vigilance and predator avoidance in a single bird.

摘要: In an aviary experiment with captive Goldfinches (Carduelis carduelis L.) vigilance and foraging behaviour were recorded before after the appearance of a predator. When foraging, individual had low head jerk rate during first minute, but each scan was relatively expanded duration; scanning increased shorter duration up to time predator, Merlin (Falco columbarius), appeared. Thereafter birds showed rate, which returned former level ten minutes. The spent feeding if high high. There significantly more scans long predator visible compared undisturbed feeding. intake loss individuals due following minutes is calculated be 53%. A linear, negative regression function formulated relating number per unit total scanning: [Formula: see text] With vigilant decreased. From this concluded that ingest large sized seeds therefore only few they gain higher security against predators on small ingesting more, because not pecking rate.