Howl city

An annual roundup of coyote pups allows researchers to study the Cook County population

May 21, 2013|By Chris Walker, Chicago Tribune reporter
  • In an image from a video camera placed inside a coyote den, Mike Neri, a wildlife wildlife biologist for the Forest Preserve District of Cook County, returns a pup after examinations.
In an image from a video camera placed inside a coyote den, Mike Neri, a wildlife wildlife biologist for the Forest Preserve District of Cook County, returns a pup after examinations. (Chris Walker, Tribune photo)


Mike Neri's voice echoed through a suburban forest preserve, announcing his find. He was quickly joined by fellow wildlife biologists who had been combing the underbrush looking for a coyote den. They found Neri scrambling though an ancient junk pile, plucking puppies from rusting car remains.

On that recent moist spring day, the researchers rounded up eight coyote pups, surprisingly docile and predictably adorable.

Under the white noise of the nearby Jane Addams Memorial Tollway (Interstate 90), the scientists began collecting data on the animals as part of the Cook County Coyote Project, a study of coyotes in the Chicago area run since 2000 by the Max McGraw Wildlife Foundation, the Forest Preserve District of Cook County and Cook County Animal and Rabies Control.

The findings could show that coyote numbers have about reached their limit in the six-county study area.

"We're not done yet, but the indications are the litter sizes are not as large as they were in the past," said Stanley Gehrt, the Ohio State University wildlife biologist who leads the study. "This will probably be the lowest average litter size we've had since the study began. It should indicate that the coyote population is hitting a plateau."

To find the dens, the team uses a combination of technology and old-fashioned animal tracking. Telemetry readings from radio-collared coyotes produce mapped location points over time, and the color-coded points show the movements of particular animals.

But that only gets them close.

Typically, a team of four to six researchers fans out, whacking through the brush looking for holes surrounded by fresh digging or other signs, such as tracks, fur or scat. Sometimes they find two or more in a day, but often they strike out.

At a promising site near Hoffman Estates, a team recently dug for an hour. Forest preserve biologist Chuck Rizzo wormed his way in and explored it with his burrow cam — an infrared camera with its cable stiffened by a noodle, one of those long, floating pool toys. He was pulled out by his feet, looking disappointed.

"It's par for the course," he said. "Sometimes you put a lot of effort in and nothing in return."

The search is exhausting but competitive — and kind of a rush.

"Every year, this is one of the best parts of the project — rounding up the pups," said Neri, who also works for the forest preserve district and who found the litter in the junk pile. He has been involved from nearly the start of the project. "You really don't know what to expect, but when we get to an area that we know there's a female denning, we go in as quick as we can to surprise them."

Ideally, researchers want to get to the pups before they can return to the den or scatter too far.

"They're a lot easier to catch now than in a couple of weeks when they get their legs under them," Neri said. "Then it really gets crazy, running through the brush and trying not to fall while you're trying to net a pup."

When a den is found, researchers put their ears to the opening and listen. The mother may still be close, so sometimes they can hear her barking — either to warn the pups or draw away the intruders.

"We pull the young ones out, and we'll process them, take hair samples or blood. We'll put a PIT (passive integrated transponder) tag in them in case we encounter them again," said Chris Anchor, who leads a team of fellow wildlife biologists for the forest preserve.

"If they're over about 3 pounds in size, we'll put collars on them, but if they're not, we'll just put PIT tags in them, take measurements, photographs, and then put them back in the hole.

"And then momma will come and take care of them."

To anyone worried about a coyote invasion, Anchor is reassuring. "The great thing about coyotes is that they're self-limiting. They're very territorial. They don't allow interlopers."

When invaders enter urban territories, "they just keep moving, because each way they turn they're getting beat up," Anchor said.

Furthermore, as Gehrt explained, females produce smaller litters when food is scarce or populations increase. As for the predicted lower numbers this spring, "we have no indications food has decreased, so it's probably due to population density."

But for the estimated 2,000 coyotes in the area, Anchor said the "vast majority are among us and nobody knows. They are not causing a problem. The ones who do, it's because they're being habituated, and that's because people feed them."

Heidi Garbe, associate research scientist at McGraw, agrees.

"They're doing their job. They're staying undercover for the most part and working around us."

But she urges the public to adapt as well. "You just can't assume you can put your little dog out there (in the yard) anymore — even your bigger dog. The coyote just doesn't know. That's free game."