Look up at dawn or dusk in any Northeast neighborhood in winter and chances are good you’ll see a stream of crows. Sometimes they’re tiny black specks high in the sky, other times they fly low, just above rooftops.
Dozens after dozens after dozens, they fly toward the south at night, in the morning returning northward, calling to each other with their caw, caw, caws.
Where are they going? And what are they up to when they’re not commuting?
We asked those questions of local bird expert Sharon Stiteler, also known in birding circles as Birdchick. In addition to bird-related speaking gigs, maintaining birdchick.com and working as a guide, Stiteler leads birding programs as a park ranger for the Mississippi National River and Recreation Area.
She explained that in the evening the Northeast crows join tens of thousands of other crows to sleep in treetops at a central location called a roost. The roost is fluid with respect to location, shifting from day to day and year to year. Sometimes it even changes in a single night: If the birds are startled they’ll all rise up and fly en masse to another spot.
This year they’ve been filling the trees around the East and West bank campuses of the University of Minnesota. One evening in early February, as viewed from the Washington Avenue walkway, thousands of crows flew in from all directions, circling, settling onto branches on trees on both river banks. Now and then whole groups would take flight again, rising in a wave, and settling somewhere else, their caws and rachetty rattling sounds filling the air.
Stiteler said that studies have shown that some crows might travel as many as 20 miles to the roost, so our crows from Northeast might be sleeping alongside those from Dakota County. She hasn’t done a count on the university roost, but about nine years ago, she counted nearly 50,000 crows roosting in Loring Park.
Why do they gather in such large groups? “The roost is essentially a safety issue at night,” Stiteler said. “If you’re one of five thousand, you’re less likely to be plucked off by a great-horned owl in the middle of the night.”
There also might be some kind of information-sharing function of the roost, with the birds paying attention to the condition of their roostmates and the direction in which they set out in the morning, according to a talk by a crow researcher on Cornell University’s All About Birds website, a site that Stiteler highly recommends for anyone interested in birds.
When the birds return to the neighborhoods in the morning, it‘s all about foraging for food. You’ll see them in small groups dumpster diving, eating berries, picking at the ground for grubs or working over an animal carcass. They’re also hunters – mice, baby birds and young rabbits and squirrels are all fair game, Stiteler said. They’ll dine on other birds’ eggs, and insects as well. “If it’s big and juicy, they’re interested,” Stiteler said.
The small groups of crows we see during the day are likely extended families, Stiteler said. The young from previous years help their parents raise new broods, with some offspring staying with the family for as many as six years before breeding themselves, according to the All About Birds web site.
At this time of year, the crows start looking for good places to build their nests. Nest building starts in March, and then the daily migration to the roost will end. “Once their hormones kick in for mating season, they don’t have the tolerance to be around other crows. They’ll break off into their family groups and start building nests and raising young,” Stiteler said.
But for the next few weeks, late afternoon, keep an eye out for the family groups converging in our Northeast neighborhoods. They gather in the hundreds in trees and parks, staging before taking to the skies as a flock. If you start early and can follow the lines of crows to their roost, wherever that might be for the night, you’re in for a wondrous sight.