Why do crows suddenly appear? A legion of urban fans appreciate this winter phenomenon

Tabithah Polinske was about to hop into her car and run an errand when she became mesmerized by thousands of crows crisscrossing the Minneapolis sky.

The trees in her Phillips neighborhood were thick with the cawing birds. And above, multiple murders of crows were streaming in various directions, stretching all the way to downtown's U.S. Bank Stadium.

"I could see them clouding the sky for miles," she recalled.

If you're having a hard time picturing this, just imagine what it sounded like.

"They are crapping on me — yes, that is the noise you are hearing," Polinske said while recording video on her cellphone as crow poop plopped onto her hat and collar and splattered all over her car. "So. Many. Freaking. Crows. Holy literal crap. Wow. So insane. So glad I have napkins in my glove compartment."

Despite the occasional mess, urban crow-watching enthusiasts like Polinske delight in the coldest months of the year, when crows gather by the thousands in Minneapolis, St. Paul and Rochester. It has become such a phenomenon every winter that there are Facebook groups in which spectators exuberantly post their sightings.

The images show crows flapping past familiar city haunts — Loring Park, the Basilica of St. Mary, the Mississippi River, or a periwinkle downtown skyline just as the sun starts to recede for the night. Most captions are brief and involve some variation of the phrase "CAW cawcawcaw CAW CAW!!"

The fascination around crows seems to buck the conventional wisdom that most people despise them. Crows are the stuff of horror movies, as famously parodied in Schitt's Creek.

Are these Hitchcockian tropes unjust?

"Yes," says science teacher and photographer Karen Kraco, who has been chasing them with her camera for the past several years. "They don't care about us much at all. They're just busy living their lives. It's like another culture — when people don't know about another culture, they're afraid. But they're our neighbors."

Kraco, known to some friends as Karen "Kra-crow," likens her artwork to a form of street photography. The first time she followed the crows after a small group took flight from her northeast Minneapolis neighborhood, she stood in awe when she arrived at their destination: the University of Minnesota's West Bank, just as the sun was setting.

"There were thousands and thousands of them coming from all directions," she recalled.

Crows are communal roosters, flocking to particular locations as a form of self-protection, said Dudley Edmondson, an avid birder, author and wildlife photographer. You may see them hang out in smaller groups in your neighborhood during the day and retreat to the so-called "mega-murder" before nightfall.

"These birds are smart. They communicate with one another, which is part of the reason they gather up," said Edmondson, who lives in Duluth. "The more eyes, the safer they are. Crows get together in these large roosts and spend the night together for safety."

The pack mentality of crows doesn't end there. He's watched crows rely on their numbers to outsmart bald eagles feeding on deer carcasses. Edmondson says one crow will volunteer to be the instigator, nipping at the tail feathers of the eagle. Regal as it may be, the unwitting raptor will turn around to see what's pecking its behind, while the other crows dive into the fresh meat of the deer.

"They'll even sit at street corners waiting for squirrels to be run over because there's meat they want to eat," he said. "They stop at traffic lights, waiting for something to be killed."

Edmondson mentions all of these things in admiration: Crows recognize human faces. They can solve complicated puzzles.

"Crows are cool," he said. "These birds are wicked smart — they just are."

But many things about them remain a mystery. Kraco, the science teacher, wants to know more about their patterns. What is the signal they use to migrate? How do they figure out which places to roost?

Perhaps the exhilaration some crow enthusiasts feel has more to do with a propensity to embrace the surprises of urban life. Granted, "crows don't have a very beautiful call," Polinske said. But in the city, she said, "you don't have too many of these big nature events you can see. You can't ignore it."

A decade ago, Gabe Sehr founded one of the Facebook communities, "Minneapolis Crows: the Mega-Murder," after witnessing a massive cluster of crows for the first time. He created the group so that others could easily learn more and share information after they experienced their own moment of urban wonder.

"Very quickly others who had witnessed the marvel of the murder started showing up, gathering not unlike the crows themselves," he told me.

Today his community has nearly 5,000 people, and Sehr says there's a surge in followers every winter as people discover the giant roosts and go online to start digging into the phenomenon.

As we thaw out these next several weeks, a new crow pattern will emerge. They'll hang around, but not by the tens of thousands that we might be lucky enough to stumble upon in winter. The mega-murder will vanish, just as ice houses and neighborhood rinks fade away when the days become longer.

These birds will become less social, as we humans crawl out of our dens and become more social.

But they'll be back next winter, as straight and as sure as the crow flies.