This Week in Nature: 23-Year Study of Chicago’s Coyotes Shows Females Are Wilier

(Alan Schmierer / Flickr Creative Commons)(Alan Schmierer / Flickr Creative Commons)

Twenty-three years ago, Chris Anchor took a group of coyotes that had been captured in Chicago and Aurora and dropped them off in rural areas, thinking he was returning the wild animals to their natural homes.

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But the coyotes, which were outfitted with tracking devices, all wound up returning to the cities. That’s when it clicked with Anchor, a senior wildlife biologist with the Forest Preserve District of Cook County. These coyotes weren’t lost — they were urban coyotes, living in the city.

More than two decades later, Anchor is still studying urban coyotes as part of the Cook County Coyote Project, and he shared some of his findings at the recent Wild Things conference held in Rosemont.

Where coyote sightings in Chicago were rare in the 1940s and ‘50s, he said, today they’ve become commonplace. 

The survival rate for pups is nearly five times greater in urban environments than rural, said Anchor. But they’re not just surviving, they’re thriving. The density of the coyote population increases the closer one gets to cities, where the animals are less likely to be hunted or trapped.

Video cameras attached to some of the coyotes show them to be a savvy bunch, avoiding auto traffic through carefully timed road crossings. Because coyotes are so smart, whenever one of the research project’s collared coyotes winds up as roadkill, the assumption is that an underlying condition such as heartworm could be involved, said Anchor.

Though coyotes have learned to co-exist with urbanites — Anchor tracked the movements of one coyote who lived for years on the fringe of an Ikea parking lot — they’re still wild animals. To people who persist in treating coyotes like domesticated animals by feeding them, Anchor has one word of advice: Don't.

He’s seen too many coyotes with rotten teeth, the decay caused by human food. Feeding coyotes also habituates them to humans and provides opportunities for interactions that could turn sour, he said.

Perhaps the most remarkable aspect of the Cook County Coyote Project is its duration — studies rarely last past a few years — and the large number of animals tracked.

The total is nearly 1,500, and Anchor pointed to one interesting stat: More male coyotes have been caught and collared than females.  

"Hands down, the reproductive-age female is the hardest to catch," he said. And why’s that? Anchor paused for a beat. "They’re smarter."

Here’s what else caught our attention this week:


For folks who love winter, 2022-23 in Chicago has been a bust. Where did all the snow go? Apparently, Yosemite National Park. Record snowfall has left the park buried in as much as 15 feet of snow in some places, and more is on the way. The park is closed indefinitely, and photos show why.


Dead whales are washing up along the East Coast in alarming numbers, and humans’ love of online shopping could be to blame. Post-mortem exams point to collisions with ships — specifically massive trans-Atlantic cargo haulers — as the likely cause of death in a number of cases, according to the New York Times.


If you had “whiskey fungus” on your bingo card of environmental hazards, congrats.

The fungus Baudoinia compniacensis feeds off whiskey vapors — called the “angel’s share” — and has become a problem in towns in Tennessee and Kentucky, where large distillers like Jack Daniel’s have clustered barrelhouse operations (occasionally building without permits). Residents are complaining of a black mold coating everything in sight, from patio furniture to trees.

To quote the lawyer for one fed-up Tennessean: “The angel’s share results in the devil’s fungus.”

Great Lakes

ICYMI, the wreck of the Ironton, which sank in Lake Huron more than 125 years ago, has been found. The saddest part of this tragic accident is the loss of crew members, who managed to reach the ship’s lifeboat but couldn’t detach it quickly enough.

The intact ship and lifeboat can be seen clearly in this video shared by the National Oceanic and Atmospheric Administration.

Tweet of the Week

Note to self: Check relationship status before hiking in bear country.

Contact Patty Wetli: @pattywetli | (773) 509-5623 |  [email protected]

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