She pops up suddenly from behind a green tarp and trots through the construction site, pausing every so often to swivel her large, triangular ears. The beep beep beep of a cement paver and the deafening roar of buzzsaws are just background noise to 1242.

A few weeks ago her mate for life, 1244, was shot near this new high school going up outside Chicago. Now Lauren Ross, a field technician with the Max MacGraw Wildlife Foundation, has pinpointed the radio-collared female’s location with a telemetry unit, the constant ping revealing her exact location. Even so, it’s rare to see urban coyotes during the day, as most have learned to be active at night to avoid people. But 1242 has pups to feed. And in the indefatigable coyote spirit—that same quality that has propelled the predator into every corner of the United States—this lanky single mother is making it work without her partner.

“We consistently underestimate this animal and its ability to adjust and adapt,” says Stan Gehrt, a wildlife ecologist with Ohio State University and the Max McGraw Wildlife Foundation. Gehrt has studied Chicago’s coyotes since 2000, not long after the animals surfaced in the nation’s third biggest city. “They push the boundaries of what we perceive to be constraints,” Gehrt says.

For instance, at the beginning of his research, he thought coyotes would be restricted to parks and green spaces. He was wrong. “Now we have coyotes everywhere—every neighborhood, every suburban city, and downtown. The only place we don’t have them is airports, and that’s because they kill them.”

Native to the western two-thirds of the United States, coyotes began dramatically expanding their range in the early 1900s. They’ve increased their habitat across North America by 40 percent since the 1950s—twice the rate of any other North American carnivore—and now live in every U.S. state but Hawaii. The near-extinction of wolves, the crash of the coyote pelt market, and the explosion of food-rich suburbs fueled their rise, as did their innate tenacity forged by a million years of evolution.

“They have this amazing balance between being bold enough to hunt, attack, and kill something and being shy or savvy enough to avoid being killed themselves,” Gehrt says. And they’ve achieved this dramatic increase despite being one of the most persecuted animals in the U.S. At least 400,000 coyotes are exterminated each year, with the federal government killing around 80,000. (Read how the most hated animal in America outwitted us all.)

From New York City (one daring individual hopped onto a roof in Queens) to the Florida Keys to the Hollywood Hills, no city or climate seems off limits. Coyotes recently migrated as far south as Panama, where they’re now poised to enter South America for the first time.

When will they stop? That’s the question that fascinates many urban ecologists. So far coyotes seem to have weathered most traditional population checks, such as disease.

“What’s striking is almost all eastern states show exponential growth,” says Roland Kays, a zoologist at the North Carolina Museum of Natural Sciences and North Carolina State University in Raleigh, who studies how coyotes evolved and spread across the continent. “There’s no leveling off in most places.”

That’s why Gehrt’s Urban Coyote Research Project in Chicago—and many similar initiatives in New York, Vancouver, Los Angeles, Denver, Washington D.C., San Francisco, and elsewhere—are busy trying to figure out how people can best coexist with a predator that’s here to stay.

Pup surprise

On a chilly morning at the start of the spring research season, Gehrt and other biologists are searching for coyote pups in Busse Woods, a nature reserve northwest of downtown Chicago. Gehrt captured the city’s first coyote here in 2000. Now there are 1,283 on record.

The scientists fan out across the open, sunny forest abloom with spring wildflowers such as jack-in-the-pulpit and red trillium. They poke their heads into moss covered logs—choice coyote denning sites.

Lauren Ross, the field technician, shines a light inside a decaying log and shouts, “I think I found them.” A pile of coyote pups is tucked at the far end. Shane McKenzie, a researcher with Max McGraw, fishes out two blinking, squirming pups. Another two are out of reach. “In this situation, you’re not going to give up,” McKenzie says, one arm buried in the log up to his shoulder.

Finally the team carefully tears a hole in the log and extracts the two remaining pups. (The parents would soon move their babies to a new den anyway.) Surprisingly calm, the football-size coyotes smell like wet dogs and are covered in thick, dark brown fur except on their fuzzy bellies.

Ross weighs, measures, and tags each pup, steering clear of their tiny, razor-sharp claws. “You’re 1252,” she says gently to one. A commotion ensues when technician Yasmine Hentati places the pups back in their den and discovers a fifth pup that, in classic wily coyote fashion, had evaded capture.

Testing the limits

"Busse Woods has been home to two packs of coyotes since biologists began monitoring them in 2000—a north pack and a south pack—and each year there’s been a litter born in each section. But these pups are notable because, for the first time, there’s been a second litter born in the southern part of the park—suggesting another pair of coyotes have moved into the area and apparently took over part of the southern territory.

“Life must be good for the coyotes—there are still ways for them to increase even within areas that have been occupied for many years,” Gehrt says.

Though much is made of coyotes’ flexibility, they’re rigid in two regards: their monogamy—generally both parents raise a litter of pups together—and in their need for a defined territory. This territorialism, says Gehrt, could be a factor that will limit their spread.

Common sense says that when coyotes run out of room, their population should drop. But that’s not what’s happening in Chicago. Instead, the animals are carving out niches in the most impractical and dangerous of places, such as busy downtown streets. If a young coyote simply can’t find a home, its parents will sometimes cede part of their territory, a process called "budding."

The territorial instinct is also why killing coyotes with the goal of reducing their numbers—called lethal control—doesn’t usually work. Like the game Whac-a-Mole, killing coyotes only creates a habitat vacuum, giving their competitors a chance to move in. Beyond that, coyote biology is primed for persecution: When the rate of killing goes up, young coyotes mature faster, and females produce larger litters.

Disease is another factor that usually limits wildlife populations, Gehrt notes. Canine distemper, for example, often breaks out among wild coyotes. But except for a few cases of mange and getting hit by cars—their primary cause of death—Chicago’s coyotes are oddly healthy, living even longer than rural coyotes. (Learn how coyotes are hacking life in the city.)

According to analyses of coyote trapping records in the eastern U.S. by Roland Kays, the North Carolina zoologist, it's possible that coyote populations have reached their limit—called the carrying capacity—in Maine and New Hampshire, the first eastern states they colonized. But it’s still too early to say for sure, Kays cautions.

Stewart Breck, a research wildlife biologist with the U.S. Department of Agriculture in Denver, says that the coyote population in that city has remained stable over the past decade, indicating that it has reached carrying capacity.

But, he says, “As they continue to expand their distribution on a geographic level [throughout the Americas], what are the limits?”

For some animals with specialized diets, food availability can also restrict population growth. But coyotes are omnivores, often eating fruit and vegetables—both of which are in plentiful supply in the suburbs. Yet most urban coyotes still eat a lot of wild prey—particularly rabbits and squirrels—instead of trash or human food.

Because many coyotes dwell in areas that blur the line between wild and urban, figuring out how to predict their patterns is complex. Busse Woods, for example, may look natural, but it’s an illusion, Gehrt says. At least 2.5 million people come here every year, and the park is hemmed in by neighborhoods and busy roads.

“Even in what you consider the most protected, natural areas, those coyotes are being born and raised around people and dogs.”

So far, reported run-ins with people haven't increased, even as Chicago’s coyote population continues to grow—there are now up to 4,000 in Cook County alone. But, Gehrt says, “The question is, year after year, generation after generation, will they continue to have that healthy fear of people?”

Capital coyotes

That question intrigues Megan Draheim, founder of District Coyote in Washington, D.C., one of the last American cities that coyotes colonized, in the early 2000s. Because the predators are relatively new arrivals to the nation’s capital, “I’d like to get out in front of conflict,” says Draheim, a conservation biologist at Virginia Tech. “It’s a nice opportunity to be proactive rather than reactive.”

On a summer morning at the Rock Creek Park Golf Course, Draheim and American University biologists Christopher Tudge and Lindsay Powers are out looking for coyote scat, which tells them what the animals are eating and where they’re hunting, as well as offers a peek into their DNA.

As in the case of Chicago’s Busse Woods, Rock Creek Park is quasi-natural. A helicopter drones above us, woodpeckers tap, a golf cart buzzes by on its rounds.

Draheim bends down to photograph two sets of likely coyote pawprints—one large, one small—on a dirt path that runs along the hilly back nine, a temporarily closed section of the course fringed by forests. Cresting a hill, Tudge turns and whispers, “Walk slowly!”

At the base of the hill, completely out in the open, a coyote and pup are standing next to each other, staring at us with apparently mutual surprise. The parent, its back golden in the sun, remains frozen in place, while its pup frolics about. A few seconds later, the adult slips into the forest, bushy tail disappearing last. The pup hangs back a few seconds, seemingly curious, then follows.

It’s a thrilling sighting—“The coyote gods smiled down on us,” Draheim says—and it provides valuable insight into where coyotes are using the landscape, one of the project’s research goals. Draheim has created an online citizen science reporting form so people in the D.C. region can record where they see or hear coyotes and foxes. She and Powers are also planning a “howl survey” in which they broadcast a coyote howl, then use acoustic software to identify individual coyotes that howl in response.

So far the canids have been sighted mostly in green spaces, and reports of human conflicts are relatively low. But the capital coyotes will inevitably spread into more urban parts of D.C., and Draheim hopes her data can help the city government manage coyotes and prevent conflicts with people.

She also plans to share best practices for coexisting with coyotes with schools and local communities. Guidelines include keeping pets inside and on leash and not feeding the carnivores, which can make them more aggressive. Teaching people how to humanely haze coyotes could also keep the animals wary of people.

It probably won’t be easy, adds Draheim, who has a coyote tattooed on her left arm. Her research has shown there are usually some “people who believe that cities are human areas and nature belongs out there. Coyotes muddle that perspective of the world.”

Heading south

Like them or not, coyotes are thriving in our human-dominated era—the Anthropocene—when most species aren’t, Kays notes. “It’s a really interesting evolution story that’s happening right under our noses.”

This very instant, coyotes are literally pushing their boundaries southward. The animals first made it to Panama in 2013 as deforestation opened up dense habitat. The lawless Darién Gap is their last hurdle to reaching South America. Once there, Kays says, “They’re probably going to take over the continent in non-forested areas,” such as grasslands and agricultural lands in Colombia, Venezuela, and Brazil.

Meanwhile, biologists are busy trying to discern whether urban coyotes are bolder than rural coyotes, and if that is reflected in populations across the country. In Denver, for instance, some coyotes are "very visible and brazen," says the USDA’s Breck, while in Chicago they’re more shy, according to Gehrt.

To determine if this phenomenon of bold urban coyotes is specific to Colorado or more widespread, Kays, Breck, and USDA’s Julie Young have developed a nationwide “boldness protocol” that at least 20 cities will use to study their coyote populations—including places as diverse as Panama City, Panama; Florida; and Seattle.

“[If] we can figure it out, we can reduce people’s problems with these animals and allow them to enjoy the good side of coyotes,” Kays says.

As for Gehrt, the project that was meant to last a year is now funded through 2023. There are just too many questions to stop now.

“It’s an evolving story,” he says. “We don’t know what the final chapter of the urban coyote story is going to be.”