Each night, more than a thousand crows descend on Sunnyvale, California. In recent years a growing contingency of corvids have been roosting in the Silicon Valley town’s downtown district, filling the night air with a chorus of caws and painting the roads, Pollock-esque, with droppings.
The spectacle has failed to charm residents and local business owners. Vice-Mayor Alysa Cisneros said constituents had been complaining about the crows since she began campaigning for office in 2019. “In terms of the kinds of complaints I get on a consistent basis, crows are a top concern, right after speeding drivers,” she said.
Now the city has resolved to use laser pointers and boomboxes to chase them away from the downtown area, where residents want to enjoy al fresco dinners and meandering strolls without having to talk over the birds’ calls or dodge their poop. As in many cities that have seen urban roosts expand in recent years, town officials have been desperately seeking strategies to quickly dispel or relocate the birds.
Sunnyvale’s mayor, Larry Klein, was inspired to deploy lasers and speakers by neighboring Palo Alto, where lasers had been used, with some success, to disperse the crows congregating there.
“The idea is to use these green laser pointers, plus the recorded sounds of crows in distress, to kind of harass the crows over the next few weeks,” said Klein. “And see if they leave.”
While bird counts by the Santa Clara Valley Audubon Society have not shown any marked increase in the region encompassing Sunnyvale over the past five years, researchers say it’s plausible that increasing numbers of crows have relocated to downtown, drawn – as many locals are – to the plentiful dining options and cozy atmosphere. The district also has many trees and other landscaping features where crows can roost.
During the colder months, when they’re not nesting, crows like to congregate in larger numbers – and the warmth radiating off city roads and trapped by tall buildings provide a cozy winter home. Street lights in cities help them better surveil for predators. “It’s an ideal habitat for them,” said Kaeli Swift, a post-doctoral researcher at the University of Washington.
Sunnyvale had previously tried using a falcon to frighten the crows, with little success, Klein said. And the city is not ready to use more aggressive measures, such as pyrotechnics, against the highly intelligent birds. “You know, I have no issue with the crows, there are just too many roosting downtown,” he said. The city has had to dedicate more time and resources to spray-cleaning the sidewalks splattered with crow feces, and restaurant owners worry that birds will drive away patrons.
“If we could just reason with crows, and tell them to spread out a bit more, that would be fantastic,” Klein said.
Sunnyvale’s woes are not unique. In Auburn, New York, where crows now outnumber human residents two to one, officials have tried, and failed, to disperse the birds using lasers. Lasers have also been used unsuccessfully against crows in Rochester, Minnesota. In Indianapolis, lasers and recordings of bird warning calls did drive crows away from the business district, only to send them into a nearby, poorer neighborhood, “turning this into an environmental justice issue”, said John Marzluff, a professor of wildlife science at the University of Washington who studies corvids.
Even if Sunnyvale manages to drive its flock away from downtown temporarily, they’re likely to return unless they find another habitat where they can comfortably and safely roost. “For a long-term solution, cities need to redirect funding towards research that would help us figure out how we can create green spaces designed to house these roosts,” Swift said.
There is another option: “If you can’t beat them, join them,” Swift said.
Swift notes that crows have few negative effects on other bird populations, and can even form bonds with humans. Put a couple of peanuts out for them on your porch occasionally, and they’ll remember you and come by again and again. “They’ll bring their mates by, and their offspring,” she said. “There’s a real bond that can happen.”
Shani Kleinhaus of the Santa Clara Valley Audubon Society encourages residents to appreciate their beauty.
“In the evening, when they get moving, they create these rivers of flight across the sunset. It’s beautiful. It’s exciting,” she said. “While they are here, why not celebrate them?”
