In fact, the behavior is so prevalent among Northwestern crows (Corvus caurinus) that it shatters the long-held belief of some animal behaviorists that the birds primarily are looking for predators when they scan their surroundings, report Renee Robinette Ha, a UW lecturer in psychology, and James Ha, a research associate professor of psychology.
Their findings were recently published in the journal Animal Behaviour.
"Crows and other corvids (ravens, jays and magpies) are highly intelligent," said Renee Ha. "Among birds, only parrots match them in intelligence. Crows are social, highly cognitive birds whose intelligence is up there with dogs."
"Crow vigilance is based on the opportunity to steal food," said James Ha. "The over-riding factor in their vigilance behavior is 'who's got food I can steal,' not 'is there a predator lurking around.' It has been dogma that crows are vigilant for predators, but they really are vigilant about each other."
To observe crows, the Has needed an open, non-wooded site where the birds' behavior could be readily seen. They found it in Meadowdale Park, a suburban site along Puget Sound in Snohomish County, north of Seattle. The park is relatively undeveloped with light human and dog traffic, which might have disturbed the birds.
The researchers observed crows for 290 hours over 18 months, watching a randomly selected bird for five minutes. All observed birds, which were in groups ranging between five and 50 individuals, were within one meter of the exposed tidal zone where food was available. The birds were observed through binoculars from a dist
Contact: Joel Schwarz
University of Washington