LINCOLN PARK — Humans aren't the only mammals that frequent Downtown.
Based on the results of a successful camera trap program that recently expanded into five Chicago high schools, the researchers at Lincoln Park Zoo's Urban Wildlife Institute have discovered two other mammals that routinely roam the city's streets, parks, alleys and lakefront.
"Raccoons are everywhere, by far the most urban-adapted species, and they're followed right by the coyote," said Mason Fidino, the coordinator of wildlife management for the Urban Wildlife Institute, which studies the interaction between urban development and the natural ecosystem.
"Whether you know it or not, if you're taking a walk in the city, you've likely walked past a coyote," Fidino said. "Most of the time you just can't see them."
The issue with not seeing them led to the creation of the camera trap program, which began in May 2010. The institute installed infrared camera traps, which sense an animal's heat and motion, along three transects — or sampling lines — that start Downtown and head out of the city.
There are 41 camera traps within city limits, and all are near the transects, which run along the Chicago River heading northwest, Roosevelt Road running due west, and the Illinois and Michigan Canal going southwest. The exact locations of the camera traps were not revealed because the devices are sometimes stolen or vandalized, Fidino said.
The last 3½ years of study have led to about a million camera trap photos, plus multiple discoveries of where mammals live within Chicago and how close they'll wander to Downtown, Fidino said.
Among the findings:
• Besides raccoons and coyotes, opossums are the mammals that come closest to the city's epicenter. Opossums will travel into areas like Humboldt Park, Wicker Park, Lakeview, North Lawndale and Bridgeport, but they won't go into Downtown because they tend to like more green space.
• Deer, red foxes and skunks — the striped stink-sprayers were considered the "least urban" mammal — were almost never photographed by the camera traps except on the Northwest Side in neighborhoods like Edison Park, Jefferson Park, Albany Park and Forest Glen. Fidino said they also are in Far Southwest Side neighborhoods including Beverly and Far Southeast Side locales like Hegewisch, but the institute hasn't installed camera traps in those places yet.
• The city's river system and railway corridors are by far the primary wildlife gateways into the city.
• Animals have adapted their lifestyles to the urban environment. For example, coyotes in rural locations are usually most active at dusk and dawn, but in Chicago they do most of their hunting overnight.
"When animals are living in the city, a lot of their paradigms break down," said Liza Lehrer, the institute's research coordinator.
Fidino and Lehrer consistently add more camera traps. Ones recently installed near Montrose Harbor and Jackson Park photographed coyotes. They'd also like to create other transects that run through other Chicago neighborhoods.
The institute, in conjunction with the Hurvis Center for Learning Innovation and Collaboration, this fall launched a yearlong "Partners in Fieldwork" program with five Chicago high schools — Amundsen, Manley, Providence St. Mel, Taft and George Washington — in which students have set up camera traps outside the schools. The students' camera trap results will be incorporated into the data the institute already has collected, said Sharon Dewar, Lincoln Park Zoo's director of public relations.
"The goal is for the students' data to be usable for our scientists," Dewar said.
Fidino said the objective of the entire camera trap project is to understand what types of habitats attract wildlife and what kinds of wildlife are living in the city.
Lehrer said she's been amazed by the animals that can be found within Chicago, even if the cameras haven't captured them on film. She's seen a mink at the North Park Village Nature Center, and she said that even beavers occasionally traverse into these parts.
"We're only going to start seeing more and more wildlife in the city, and we'll need to be able to coexist with them," she said.