"The coyote is the test case for other animals. Raccoons, skunks, foxes -- they've already been able to penetrate the urban landscape pretty well," said Ohio State University Professor Stan Gehrt, who has been studying coyote populations near Chicago for 12 years.
"The coyote is the most recent and largest. The jury's out with what's going to happen with the bigger ones."
Bigger carnivores such as wolves, mountain lions and bears could be next, researchers said.
Mountain lions are already making appearances near Chicago and recently in Des Moines, Iowa, and a family of black bears has recently been seen roaming suburban streets in Cedar Grove, N.J., National Geographic reported.
"The funny thing is that now we have more people on Earth and bigger cities than ever, we also now have carnivores moving into cities," Gehrt said.
"We used to think only little carnivores could live in cities, and even then we thought they couldn't really achieve large numbers," he said.
"But we're finding that these animals are much more flexible than we gave them credit for and they're adjusting to our cities."
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