Cities are one of the fastest growing habitat types for people—and wildlife. And increasingly diverse urban ecosystems are inspiring creative living arrangements.

By Sarah DeWeerdt

To the human eye, a city looks like unpromising habitat for wildlife: a jumble of asphalt, chain link, and scraggly weeds—hardly fit even for a starling.

But animal species often have a more complex view of our homes than we do. Cities “have more diversity than people think,” says Seth Magle, director of the Urban Wildlife Institute at Chicago’s Lincoln Park Zoo and one of a small but growing band of ecologists studying the animals that have carved out niches in the concrete jungle. “The closer we look, the more species we find in cities,” he adds.

Take, for example, the prairie dog, which thrives in towns-within-towns all along the Front Range of the Rocky Mountains in Colorado. “We like to grow a lot of grass in cities, and prairie dogs like to eat a lot of grass,” says Magle, whose graduate research focused on urban prairie dog colonies.

On the open range, prairie dogs act as a keystone species, and Magle found that they retain at least part of that role within cities as well. By eating grasses, prairie dogs encourage the growth of forbs and decrease the litter layer in patches of vegetation around their colonies, meaning that these rodents shape the urban environment as surely as humans do, if more subtly.

Such findings illustrate why ecologists are starting to sit up and take notice of urban wildlife, and this alertness comes not a moment too soon. Cities are, after all, one of the world’s fastest growing types of habitat—and some of the most rapidly expanding cities are located near biodiversity hotspots. “If we’re going to conserve all these species that we want to conserve, we’re going to have to work in the cities too,” Magle says.

Prairie dog photo by Raymond Gehman/National Geographic Creative

_____________________