The long persecuted coyote is not vermin, after all. Researchers are now discovering that it's a resilient, adaptable predator that's not just surviving in U.S. cities but playing a valuable role in restoring the food chain for the benefit of birds and other species.
Having long inhabited the western prairie, coyotes began expanding to the continent's coasts about 40 years ago. Their growth has coincided with the disappearance of gray and red wolves, from the Northwest to the Southeast, through decades of trapping, poisoning, and hunting. From 1900 to about 1965, for instance, no wild coyotes were found in southeastern states. By the 1970s, when red wolves were finally eliminated, coyotes had moved in to most parts. "It's a strong behavior in the canid family," explains Gehrt. "When they reintroduced wolves to Yellowstone, coyote numbers dropped. The wolves killed coyotes. Coyotes do the same to foxes." Removing wolves opened up habitat where coyotes could take over as the top predator.
In the late 1990s Cook County Animal Control started receiving calls about coyote sightings. "We thought there were a few coyotes, and they were just moving through the area," says Gehrt. "I thought we would do a one-year study, collar six or seven coyotes, and that would be it." Today, at any given time, his team is actively tracking 50 to 60 animals, though they've likely never seen most of the coyotes that call Chicago home. Thousands live within the county, alongside the metropolis's five million residents, who for the most part don't even realize the animals are there--save the occasional newsworthy pet snatch or visit to a Quiznos sandwich shop, as happened in 2007. In north Chicago, residents report that the blaring sirens of ambulances sometimes elicit a mournful howling chorus from nearby coyotes: ow-ow-ow-rooooo.
In 2000 the biologists placed their first trap in Busse Woods, a 437-acre nature preserve four miles from Chicago's O'Hare Airport, in an area off-limits to the public. "We knew if we caught someone's pet, the project would be over," says Gehrt. They captured a two-year-old female coyote, collared and tagged her, and released her.
That night Gehrt drove to Busse Woods. He turned on the receiver, but instead of the chirp, chirp, chirp of Coyote 1's radio frequency, there was silence. He drove from one end of the park to the other. "At this point, I'm worried we messed up," he says. "She had to be in the park, right?" Finally, desperate, he started searching outside the park. "Sure enough, the signal was coming from the city, from the urban matrix."
He followed the signal, driving along I-90 for more than a mile before turning into a subdivision. "I was amazed at what I was driving through. A highway, busy streets, businesses, homes." The chirping grew faster as he got closer. At about 11 p.m. he stopped in front of an undeveloped lot, his headlights illuminating three men holding leashes. Their dogs were in the field, about 60 feet from Coyote 1. "Three men, three dogs, all that close to a coyote, and none of them knew it. But she knew it. She kept still until they left."
Coyotes, Gehrt quickly learned, are good at navigating the city largely unnoticed, in part because they're mostly nocturnal, unlike rural coyotes, which hunt day and night. They might follow railroad tracks or the linked greenways many cities are creating. They cross frozen waterways and scale fences--one somehow made its way into a Chicago prison yard, over three 20-foot chain-link fences topped with razor wire. "Our knowledge of coyotes is evolving," says Gehrt. "We consistently underestimate how adaptable coyotes are--how quickly these animals can learn."
It's one thing to cross a suburban street; it's another entirely to safely cross I-90, as members of one Chicago pack do regularly. "We've seen them sitting on the side of the highway," says Gehrt. "We think they're listening and looking. When there's a break in traffic, they bolt. If there's a median, we've watched them go to it, stop, watch, and wait for another break, then bolt across."
Cars still account for about 70 percent of urban coyote deaths, but the urbanites tend to outlive their rural counterparts, some living to be 10 or 12 years old. The annual mortality rate for urban coyotes is 35 percent; in rural Illinois it's about 60 percent. Hunting and trapping account for the big difference, Gehrt explains.
As other coyotes and development have claimed Chicagoland's less populated fringes, individuals have moved into denser areas. "The increasing availability of green space is giving them territory they didn't have before," says Gehrt. "And their territorial system, their social system, is constantly pushing animals into habitat they would never go in otherwise. Young coyotes are constantly being forced into what we see as marginal areas in the urban matrix."