Avian Street Smarts

While cities are notoriously dangerous for birds, one particular hawk has successfully adapted to urban life and, thanks to a pedestrian crossing signal, has learned to hunt the smart way. 

Taking his daughter to school one day, zoologist Vladimir Dinets noticed that the intersection near his house was rarely backed up.  

However, if a pedestrian pressed the pedestrian-crossing button, the red light would then last 90 seconds, causing a backup of cars. The button also produced a sound, informing the visually impaired that it is safe to cross. 

Dinets noticed that the line of waiting cars stretched back to a small tree with a very dense crown. 

“One winter morning I was in my car waiting for the light to change and suddenly saw a Cooper’s hawk (Accipiter cooperii),” Dinets, the author of a new study, said in a statement. “It emerged from that small tree, flew very low above the sidewalk along the line of cars, made a sharp turn, crossed the street between the cars, and dove onto something near one of the houses.” 

He found that the hawk was diving to the front yard of a house inhabited by a family that frequently dined outside, leaving behind crumbs, which attracted a small flock of birds – sparrows, doves, and starlings, for example – which, in turn, attracted the hawk. 

That meant, Dinets said, that the hawk understood the connection between the crosswalk button’s sound and the growing line of cars, and that it would give it cover to attack prey.  

“The bird also had to have a good mental map of the place,” he added. “Because when the car queue reached its tree, the raptor could no longer see the place where its prey was and had to get there by memory.” 

The Cooper’s hawk is one of the few birds that has successfully adapted to city life. Still, Dinets says he observed this behavior in one specific bird, not in the entire species. 

Cooper’s hawks don’t nest in West Orange, New Jersey, the home of the Dinets. That means the bird was a winter migrant that, in just a few weeks, had figured out how to navigate traffic signals and patterns to hunt.  

“Next winter I saw a hawk in adult plumage hunt in exactly the same way, and I’m pretty sure it was the same bird,” wrote Dinets. “The following summer, the sound signal at the streetlight stopped working, and the residents of the house moved out. I haven’t seen any Cooper’s hawks around here ever since.”