One winter morning in suburban New Jersey, Vladimir Dinets stopped at a red light — and saw something he couldn’t believe.
A Cooper’s hawk shot from a small tree, flew low over the idling cars, and vanished into a front yard across the street. Moments later, it reappeared, talons full, having snatched a sparrow from a family’s lawn. But what truly stunned Dinets was the precision of the attack. The hawk had launched only after a pedestrian had pressed the crosswalk button, triggering a longer red light and a longer line of cars — perfect camouflage.
Dinets, a zoologist and mathematician at the University of Tennessee and Rutgers University, was witnessing a bird that had hacked the rhythms of the city. In a study published in Frontiers in Ethology, he documents what may be the most sophisticated use of traffic patterns by a wild animal ever recorded.
A Hawk Among Stoplights
At first glance, the Cooper’s hawk (Accipiter cooperii) might seem an unlikely urbanite. It’s a stealthy forest hunter, evolved to dart between trees in pursuit of small birds. Yet as cities have grown, some Cooper’s hawks have followed. Urban life is dangerous — full of windows, wires, and unpredictable cars — but it also brims with prey.
What Dinets observed over months of early-morning stakeouts was far more than mere adaptation. It was deliberate strategy.
In the winter of 2021–2022, at an intersection in West Orange, New Jersey, he repeatedly saw a juvenile Cooper’s hawk wait for a specific sound — the pedestrian crossing signal that chirped when someone pressed the walk button. That sound meant the light would stay red for 90 seconds instead of 30, enough time for cars to pile up along the curb. Once the cars stretched far enough to reach a bushy tree near the intersection, the hawk would appear.
Perched low and hidden behind the car queue, the raptor would bide its time. Then it flew — low, swift, and nearly invisible beneath the canopy of vehicles — before crossing the street and plunging into a yard frequented by sparrows, doves, and starlings. They gathered each morning to feed on crumbs left behind by a family that dined outdoors the night before. The hawk struck with shocking accuracy.
“It was the same every time,” Dinets wrote. “The hawk appeared in the tree in front of house #11 as soon as sound signals . . . indicated that red light will be longer than usual, and attacked when the queue of cars reached house #8, making it possible for the hawk to move to the tree in front of house #1 without being visible to potential prey.”
Smarter Than You Think
Dinets argues that the hawk had formed a mental map of the neighborhood. It couldn’t see its prey from the tree, blocked by cars and buildings, so it had to memorize the layout and calculate its approach. It also had to understand cause and effect — recognizing that a specific sound led to a predictable change in the urban environment.
That’s not basic conditioning. “The observed behavior required having a mental map of the area and understanding the connection between the sound signals and the change in traffic pattern — a remarkable intellectual feat for a young bird,” the study concludes.
Raptors are not generally known for being gifted. Tool use and abstract reasoning are more famously documented in corvids — crows and ravens — and parrots. But studies are increasingly revealing hidden depths in other bird brains.
Indeed, hawks and falcons have been documented using burning sticks to spread wildfires, hunting cooperatively, and even driving prey into plate-glass windows.
But this instance is unique. Urban Eurasian sparrowhawks in Ukraine have been observed using cars and streetcars for cover. Yet no case before has shown a bird using a sound — designed for human pedestrians — as a predictive tool for ambush.
Urban Wildlife Adaptation
Dinets believes it was the same hawk, now an adult, that he later spotted using the same technique the following winter. But after the pedestrian signal broke and the family moved away, the birds stopped coming — and so did the hawk.
“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. The following summer, the sound signal at the streetlight stopped working, and the residents of the house moved out, so there were no more bird flocks. I haven’t seen any Cooper’s hawks around here ever since,” Dinets wrote in an editorial.
Most urban Cooper’s hawks in New Jersey are winter visitors from non-urban regions. This bird had likely learned fast, within just weeks of arriving.
Urban wildlife encounters often center on nuisance or novelty. Coyotes in backyards. Bears in garbage bins. But increasingly, researchers are turning their gaze to the subtle, intelligent behaviors that help some species not only survive in cities but thrive.
A city intersection might seem a bleak place to study nature. But as this hawk reminds us, it’s also a stage where evolution plays out in real time.
“Cooper’s hawks manage to survive and thrive there,” Dinets writes, “at least in part, by being very smart.”
