Ospreys: High Hopes for Nesting Platforms...And You Can Help

If it’s spring, we’re out in the field – and we could use your help. Recently, our conservation programs specialist Maggie Jones checked in on a few of our South Side projects to do a post-winter look.

Among them were osprey nesting platforms.

Friends of the Chicago River help oversee five such platforms for these large raptors: Skokie Lagoons near Tower Road, the Chicago Botanic Garden in Glencoe, Erickson Woods in Winnetka, Whistler Woods in Riverdale and Beaubien Woods near 130th Street and the Bishop Ford Expwy. in Chicago.

The five nesting sites are on top of poles soaring some 70 feet above the ground topped by a flat platform the ospreys use to build their "nurseries."

"Osprey depend on waterways with a healthy fish population. By continually improving our local Chicago River system, we invite these awesome birds back every year and hope for a nest on one of the poles to ensure future generations," said Jones.

For example, the Beaubien Woods location is near the Little Calumet River where the birds can snatch fish with their talons to bring back to the nest. The height also helps protect them from predators such as raccoons (though stainless steel bands are designed to thwart them, too.)

These raptors are a deep, glossy brown on their upper parts and predominantly white on the head and under parts. You’ll know them by their distinctive black eye stripe that goes down the side of their faces. They also have short tails, long, narrow wings with four long, finger-like feathers and a six-foot wing span.

Listed as an Illinois state-endangered species, ospreys winter in Florida, Mexico and South America and return to northern Illinois in April. Females lay three or four eggs and guard them while the males fetch food. About two months after the osprey hatch, the young ones take their maiden flights from way up top.

Friends installed two osprey nesting platforms in 2015, with two more in 2016 and one in 2018. The 5,200-pound poles are funded through the generosity of an anonymous donor.

However, the public can help. We need volunteer wildlife monitors to visit the sites at least twice a month and report back on what they see. Groups and families are encouraged, though those under 18 must monitor with an adult. And no experience necessary!

We have some spring training sessions coming up:

Wednesday, April 11, 6:00 p.m. to 8:30 p.m. (includes dinner)
North Park Village Nature Center, 5801 North Pulaski Road, Chicago, IL

Saturday, April 14, 9:15 a.m. to 11:45 a.m. (includes breakfast)?
North Park Village Nature Center, 5801 North Pulaski Road, Chicago, IL

Thursday, May 17, 5:30 p.m. to 8:00 p.m. (includes dinner)
REI – Lincoln Park, 1466 North Halsted St., Chicago, IL

Saturday, May 19, 9:30 a.m. to 12:00 p.m. (includes breakfast)
REI – Lincoln Park, 1466 North Halsted St., Chicago, IL

Please only register for one date, as all sessions contain the same content.

To register, please email our Ecology Outreach Manager Mark Hauser at mhauser@chicagoriver.org or call 312-939-0490 ext. 11.

"Be the first to tell us that osprey are building a nest on the pole. Join us this season out in the field, where you’ll be the eyes and ears on the ground for the return of this awesome bird," said Jones.

In March, the Forest Preserves of Cook County Board of Commissioners recognized Friends' work in the field, passing a resolution noting the installation of the five osprey nesting platforms as well as restoring 100 acres of nesting habitat for turtles and six bat maternity colonies.

“Friends of the Chicago River has been an exemplary partner to the Forest Preserves for decades, sharing knowledge, expertise, time and energy to enhance the ecological health of the river and adjacent lands,” the resolution said.

VIDEO: Watch from a bird's-eye view.

VIDEO: Workers erect a 70-foot-tall osprey nesting platform pole.

SEE: How the nesting platforms were built.

Did you know...?

  • Ospreys dive at speeds of 80 miles per hour into waterways headfirst and then use their talons to hook fish. They are successful in about one in four tries.
  • A dramatic decline in osprey populations occurred between the 1940s and 1970 because of eggshell thinning caused by the use of the pesticide DDT.  Their populations grew by 2.5% per year from 1966 to 2015, according to the North American Breeding Bird Survey.
  • Ospreys return to the same breeding area each year.
  • Bald eagles will sometimes chase ospreys in order force ospreys to drop fish; eagles sometimes catch the released fish in mid-air. After an osprey catches a fish, it turns the fish head-first to reduce aerodynamic drag.
  • Their nests are made of sticks, lined with bark, sod, grasses, vines and algae, and are re-used year after year. The nests can become ten feet deep and three to six feet in diameter.
  • Young osprey make their first flight 60 days after hatching but remain with their parents for up to two months.
  • They live seven to ten years but there have been reports of at least one living to age 25.

Sources: U.S. Fish and Wildlife Service, Cornell University Lab of Ornithology