Early Sunday morning, a campus security officer at Columbia University saw three unusual animals hanging out in front of Lewisohn Hall, one of the school’s classroom buildings. The officer called NYPD, and according to a memo from the school’s public safety chief, the responding officers spotted one of the animals before it slinked away.

They recognized it as a coyote.

A second sighting was also reported by school employees on Sunday, the memo said, although police couldn’t confirm that one.

I’m a graduate of Columbia’s journalism school (just two buildings south of Lewisohn Hall) and an adjunct professor there, so I can attest that seeing a coyote on campus is pretty unusual. (Squirrels, rats, and pigeons, yes. Coyotes, no.) But considering the spread of this iconic Western animal across the Northeastern United States in recent years, it can’t be considered a big surprise, either.

Back in 2006, a coyote led police — not to mention photographers, helicopters, tourists, and the news media — on a wild two-day chase through Central Park before he finally succumbed to a tranquilizer dart. “Hal,” as park workers nicknamed him, was a media sensation, but he wasn’t the first coyote to try making a home in Manhattan.

Several weeks before “Hal” swam across the Central Park duck pond to avoid capture, another coyote was found dead on Manhattan’s Upper West Side (apparently hit by a car). Since 2006, more coyotes have been sighted and captured. Last month, one was nabbed at a cemetery in Harlem. And just last week, a photographer took pictures of a coyote crossing a frozen Central Park pond.

Where are these Western intruders coming from? Probably The Bronx, which is the only borough of New York City that’s part of the mainland United States. (For those unfamiliar with New York geography, Manhattan is its own island, as is Staten Island, natch. Brooklyn and Queens make up the western shore of Long Island.) Over the last decade, coyotes have established a home there, and like other animals (including skunks) they’ve started migrating to the other boroughs via bridges and railroad tracks and frozen rivers in wintertime (during warmer weather, they swim).

Coyotes used to confine themselves to the Western United States — largely because their competitors the wolves had claimed the East for themselves. But with wolves largely wiped out in these parts, along with the Eastern forests they called home, coyotes — more naturally adapted to open spaces and grasslands — started spreading this way. A 2006 Salon story by Christopher Ketcham explained their colonization this way:

The coyote, ingeniously plastic, always adapting, saw opportunity. He pushed east and north and south, assuming the niche of top dog, and today his numbers nationwide are more than twice what they were in 1850. The coyote, says wildlife ecologist Justina Ray, “is the most successful colonizing mammal in recent history.”

The rate of expansion was astonishing. According to Ray, who works with the Wildlife Conservation Society, the coyote’s march during the 20th century covered thousands of miles, even reaching isolated regions in the Atlantic provinces of Canada, including Nova Scotia and Cape Breton Island, arriving in Newfoundland on sea ice as early as 1987.

Today, coyotes live in or near every major American city. They are reported in Atlanta, Toronto, Portland, Maine, running across a schoolyard in Philadelphia, hiding under a taxi in Chicago, and everywhere in the metro west, including Denver, Phoenix, Los Angeles, and Las Vegas. A landmark study from Ohio State University, to be published this spring, tracked coyote behavior in urban Chicago for six years, concluding that the Windy City’s coyote population was vastly larger — at least 2,000 and growing — and more successful than ever expected. Urban coyotes, the study found, live longer than their country cousins, their range per pack is more compact (much like urban humans), and they hunt more often at night (also like urban humans). The study also found that the creatures likely do not pose a threat to people.

That last sentence should come as a relief to Columbia students and other Manhattanites, because it looks like we’re going to have to get used to coyotes as neighbors. Spring is when coyotes disperse from their packs to establish new hunting grounds. So the sightings so far this winter could be just a prelude of what’s to come.

Now that I know what they’re after, however, I won’t be too concerned about running across one. After all, they’re just doing what all New Yorkers engage in from time to time: hunting for real estate for a growing family.

Good luck to ‘em.

This story originally appeared at OnEarth magazine.