4 minute read
Flight Of The Falcon
Molly Meister
Molly Meister is a publications supervisor in the DNR’s Office of Communications.
Peregrine Population Ticks Upward
What's the fastest animal on the planet? Cheetahs may come to mind, or perhaps a sailfish zooming through the sea. The answer may surprise you: It’s the peregrine falcon.
When diving through the air chasing prey, peregrine falcons (Falco peregrinus) can achieve speeds of up to 230 miles per hour, about three times the fastest cheetah. And they live right here in Wisconsin!
For almost half a century, that wasn’t the case. By the late 1950s, peregrines were virtually extirpated from the Midwest due to the effects of DDT, a commonly used pesticide at the time. DDT passed through the food chain, eventually reaching peregrines and other birds of prey.
The chemical caused female peregrines to lay eggs with fragile shells, which either didn’t hatch or were crushed under the weight of the incubating adult.
Before DDT became a problem, experts estimate there were 24-50 naturally occurring active peregrine nests at any given time in the tri-state area of Wisconsin, Minnesota and Iowa. That may seem small, but it was as many as ecosystems could sustain.
That’s because peregrines are pretty picky about nesting sites — in the past, they nested solely on cliffsides along the Great Lakes and Mississippi and Wisconsin rivers — and they’re very territorial. The birds need at least a mile radius around their nest site, or rival peregrines will fight to the death.
Peregrine Plan
Over time, concerned folks took heed of the peregrines’ peril and, in 1987, the Wisconsin Peregrine Falcon Recovery Plan was launched.
The plan, from then-DNR conservation biologists Randy Jurewicz and Charlene Gieck, was to work with partners such as Greg Septon, a falconer and then a natural history curator at the Milwaukee Public Museum. The goal was to restore a viable wild population of peregrine falcons in Wisconsin, or a self-sustaining population of at least 10 breeding pairs by 1995.
The plan involved releasing up to 20 captive-produced birds annually, protecting nesting habitat and conducting vigorous outreach regarding conservation efforts.
“Hacking” was part of the plan — creating an artificial aerie, or “hack box,” from which to release young captive-raised falcons. In the summer of 1987, Septon used grant money and worked with local authorities to install Wisconsin’s first peregrine hack box atop the U.S. Bank building in Milwaukee.
That first year, 10 of 14 released falcons successfully fledged and survived to disperse.
‘Incredible Journey’
Subsequent releases of captive-produced young were carried out in Racine, Pleasant Prairie, Madison and La Crosse. Nest boxes were installed on office buildings, power plants, grain elevators and more. Located mainly in urban settings, most have become occupied by nesting pairs of peregrines.
“Getting to where we are today has been an incredible journey,” Septon said. “After nearly 40 years of sustained efforts, peregrines are once again nesting and raising young in Wisconsin, which shouldn’t be taken lightly.”
Since those initial efforts, DNR staff have worked with community scientists, nonprofits like the Raptor Resource Project, and hundreds of passionate people to band and track peregrines, monitor nests and boost numbers.
In 2023, there were 43 confirmed successful peregrine nests in Wisconsin, including more than 60% in urban environments.
Creating A Connection
Encouragingly, the number of successful peregrine nests at natural sites on rivers and the Great Lakes continues to grow. New nests have been documented as far north as the Apostle Islands.
Now, Wisconsinites are getting to know this species using technology such as live nest cams. Amy Ries, a naturalist with the Raptor Resource Project, touts the benefits.
“By giving ordinary people intimate access to the lives of wild animals, our work deepens the connection between people and the natural world, bringing benefits to both,” Ries said.
Learn More
For details on this project, visit The Raptor Resource Project website.
