Crows took over downtown Portland. Then they left. What happened?

Matteo Brunozzi has an unusual job: He’s a professional abatement falconer, meaning he uses a trained hawk to scare off other birds at landfills and farms — or, if it’s the middle of winter, in downtown Portland.

For the last few years, Brunozzi and his colleagues with Avian Solutions, which is being contracted by a nonprofit business association, have released raptors to fly through dense city blocks and disperse hordes of American crows.

But on this mid-March night, Brunozzi’s services don’t seem needed. There isn’t a crow in sight. He stands at a corner near the Multnomah County Courthouse, where the loudest noise is the hum of rush hour traffic, not the stadium roar of thousands of crows that typically fills the downtown Portland sky. His hawk waits in the back of his truck.

Brunozzi speaks into a walkie-talkie: “Hey, guys, we’re looking for possibly some action. Have you seen any birds yet?”

Nothing.

The scene was a lot different back in November, when thousands of crows crowded onto building ledges, street trees and statues, cawing up a deafening din and coating everything in black-and-white goo. That scene has become the bane of downtown businesses and tourists, so Downtown Portland Clean & Safe, a nonprofit that provides cleaning and security services over part of the central city, started contracting Avian Solutions to cut back on the need to pressure wash sidewalks.

On a normal winter night, Brunozzi releases his hawk — a slightly larger creature with an intimidatingly sharp beak and talons — to fly a few laps around a block or two, just enough to irritate crows so they go somewhere else.

“The idea is to push them to the east side or to green spaces, ideally,” Brunozzi said. “The riverfront park is great.”

Crow abatement services are only needed part of the year, roughly between October and April, for a couple of reasons. First, crows are smart enough to know when an area has become too hostile for their liking.

“The crows know what’s up at this point in the game,” Brunozzi said. “They’re pretty well trained, so they’re not coming in the same way they did in November.”

The other reason: Crows are extremely territorial, but only part of the year. In the winter, they spend their nights huddled together in massive roosts — usually in urban areas, where tall buildings can shield them from harsh winter winds — much like the one in downtown Portland, which attracts about 15,000 at its winter peak.

“These communal roosts provide crows with safety from predators, warmth and protection from the elements, and they also allow for exchange of information,” said Micah Meskel, interim urban conservation director at Portland Audubon.

So that cacophony swirling above downtown buildings and parks are crows gossiping about available territories, potential mates and new food sources. For instance, a less-experienced crow might follow others leaving a roost and heading to a recently harvested farm field, ripe for scavenging.

“There might be an ag field that’s got a big bloom of insects one week, or rotting pumpkins the next, and they can track that changing resource base around them by cueing in where others are going when they leave the roost,” said John Marzluff, who researches corvids as a professor of wildlife science at the University of Washington.

Come spring, crows are ready to pair up and start new families, so they return to their territories or find new ones. They tend to stick to those territories — which can typically be a couple of blocks wide — with their immediate and extended family members, who work together to raise new fledglings.

So while you might see fewer crows on building ledges in downtown Portland, you might see more in the city’s residential neighborhoods. You might also come across fledgling birds testing their wings; at first glance, they might appear to be injured adult birds.

“They typically aren’t able to fully fly for a couple weeks,” Meskel said. “So they’re hopping around on the ground. Their extended family is typically there chaperoning them and protecting them during that time, kind of showing them the ropes of the neighborhood.”

Fledgling crows can spend days on the ground as they learn to fly. They are especially vulnerable during that time, so Meskel said people should leave them alone because it can be difficult to reunite young crows with their families later.

Meskel said his office gets inundated with phone calls from Portlanders wanting to know more about their neighborhood corvids. While business owners and residents in Portland’s downtown districts might be a little sick of crows, many residents in the city’s eastside residential neighborhoods seem to welcome them.

Elizabeth Kaplan is among them. She feeds the same group of crows every day, sometimes multiple times a day.

“There’s three that are my regulars,” she said. “I think one must be the male and two females because one’s big.”

The “big one” caws loudly until Kaplan tosses peanuts onto the lawn just outside her door. Kaplan has feeders for other birds, but there’s just something special about crows.

“They’re everywhere, and I don’t know, I just fell in love,” she said, adding that she’s reading “Gifts of the Crow,” written by Marzluff.

Kaplan isn’t alone in her fascination with this mysterious corvid. Part of what fascinates people about crows, according to Marzluff, is their intelligence. Studies show that crows can remember human faces, and they can pass that information on to their young. They’re also adept at manipulating the humans around them.

“They will act almost like a dog,” Marzluff said. “They will follow people around, they will anticipate their moves, they will be waiting for them when they come out.”

Sometimes crows bring gifts to the people that feed them — hence the title of his book — like bottle caps, shiny coins, or acorns. Crows can also be a bit mischievous; if you watch them long enough, you might notice crows playing around with treasures they find (i.e. deer poop.)

Whether or not to feed crows is a topic of debate among birders. Portland Audubon says to leave them alone since it could lead to dependency or nutrient deficiencies, particularly with the food that many people toss to crows: peanuts.

“Peanuts are legumes, not tree nuts, and are extremely high in phosphorus and extremely low in calcium,” Meskel said, adding that too much phosphorous can lead to bone disease, something that Portland Audubon has found in some Portland-area fledglings.

If you’re set on attracting a murder of crows to your yard, Marzluff suggests feeding crows only small amounts around the same time of day, but with extreme caution. Your neighbors might not be too keen on the noise and mess they might generate, as happened with feuding Seattle neighbors in a lawsuit.

Crow populations are growing across the U.S., particularly in the West, because of their symbiotic relationship with humans. As human populations expand, so do crows’ ideal habitat, where endless garbage, rodents, and farms can nourish these omnivores, and where tall buildings provide shelter. Despite their growing numbers, crows aren’t considered invasive or harmful to the environment.

“They’re a native species, and they are basically a success story,” Marzluff said. “They have learned how to live with us, how to take advantage of us, and they do it very well.”