Peregrines can pursue their prey — other birds — at 60 mph in level flight and in dives of up to 200 mph, culminating in mid-air strikes.

Of 79 established peregrine pairs recorded throughout the Midwest in 1998, 52 percent were on buildings, 35 percent chose smokestacks and bridges, and only 13 percent were on cliffs (along Lake Superior).

Peregrine Falcon: On the (High) Rise
by Karen Furnweger

hey are among us, but above us. They are fiercely wild, breathtakingly fast birds of prey that have staked out territories in some of the most densely settled landscapes of Chicago Wilderness.

You might catch a glimpse of one soaring high above Michigan Avenue or, from the vantage point of the Sears Tower Skydeck, see one perched atop a peak of the AT&T building. Or perhaps, during a quiet moment in Lincoln Park, you’ll notice all the sparrows take off at once. Look in the direction from which they flew and check the outer branches of nearby trees. You could find yourself in the imposing presence of a peregrine.

The American peregrine falcon (Falco peregrinus anatum): Opportunities to see them in action are more numerous than you might think. This year, at least 14 pairs are nesting in Chicago Wilderness, following the Lake Michigan shore from Kenosha down through Evanston, Chicago, East Chicago, Gary, Burns Harbor, and Michigan City.

Remarkably, 30 years ago there were no peregrines nesting or living in the Midwest. In 1970, when the American peregrine falcon was added to the federal endangered species list, the birds had disappeared east of the Rocky Mountains; western populations numbered fewer than 400 and were plummeting. A number of factors contributed to the peregrine’s decline, including habitat destruction and malicious shootings. But nothing approached the devastation caused by DDT.

Peregrines accumulated high concentrations of the pesticide in their tissues from feeding on birds that had eaten DDT-contaminated insects or seeds. DDT disrupted calcium production in the females, and the eggs had paper-thin shells that broke under the weight of the parent during incubation.

Over the next three decades, Endangered Species Act regulations, a federal ban on DDT use, and an intensive recovery program involving federal and state wildlife agencies, universities, conservation organizations, falconry clubs, and 6,000 captive-bred chicks re-established the species across the United States. In 1999, with more than 1,600 nesting pairs nationwide, the US Fish and Wildlife Service removed the peregrine from the federal endangered species list. The birds are still protected by state endangered species legislation in Illinois, Indiana, Wisconsin, and a number of other states where local population goals are yet to be met.

As part of a Midwestern recovery program, coordinated by the University of Minnesota Raptor Center, young birds were introduced using falcon-raising techniques in 16 cities, including Chicago. The Chicago effort began in 1986 led by the Chicago Academy of Sciences, Chicago Audubon Society, Lincoln Park Zoo, and the Illinois Department of Natural Resources.

"Cities are good places for peregrines," explained Mary Hennen, a biologist at the Academy and coordinator of Chicago’s peregrine program, "because high-rise ledges, tall towers, and bridges resemble their natural cliffs." Such are the subtleties of Chicago Wilderness. Where nature did not build cliffs, people did. Cities offer ample prey and parks with open areas for hunting. The peregrine diet includes songbirds, shorebirds, and waterfowl, as well as those urban staples, pigeons and starlings.

In Chicago Wilderness, peregrine habitat includes a manmade nest box mounted 350 feet up a smokestack at Wisconsin Electric’s Kenosha/Pleasant Prairie plant. Eight nesting pairs, all of which were on eggs or brooding chicks in May, are scattered along the Chicago-area lakefront: Evanston, Edgewater, Michigan Avenue, the University of Illinois campus, Hyde Park. The Lakeview pair live just north of Lincoln Park Zoo. Perhaps the best aerial displays take place around Sears Tower. Since 1986 a pair has occupied the territory on a 34th-floor ledge at 125 S. Wacker. Three years ago, another pair moved onto an air intake structure about one-third up the northwest face of the Metropolitan Correctional Center at Van Buren and Clark, less than half-a-mile away.

Five pairs nest in the Indiana Dunes area, four of them at power plants, the other under the Cline Avenue Expressway. "The best place to see the birds," said John Castrale, nongame-bird biologist for the Indiana Division of Fish and Wildlife, "is at the Michigan City harbor. There’s a nest two-thirds of the way up the tall stack at the NIPSCO power plant. We counted three babies there."

Summer is a good time for peregrine viewing. After the young fledge in June, they spend weeks practicing their flying and hunting skills under the watchful eyes of their parents — and over the heads of the rest of us.

You can keep track of the peregrines of Chicago Wilderness on a page at the Chicago Academy of Sciences Web site, www.chias.org/biology/cprr. And keep your eyes to the skies.