Volunteers Celebrate 25 Years of Tracking Hawk Migration at Illinois Beach State Park

Standing atop a hill at Hawk Ridge Bird Observatory, in Duluth, Minnesota, Vic Berardi noticed a man with binoculars calling out names of birds of prey. All Berardi could see was a blank sky. It was at that moment the Gurnee resident became determined to learn the secret of identifying migratory hawks in the sky. This year, he celebrates 25 years of founding the Illinois Beach State Park (IBSP) Hawkwatch, based in Zion, with his friends and co-leaders Paul Sweet and his mother, Janice Sweet, also of Zion.

Hawk watching is a citizen science activity where volunteers track migratory raptors, such as hawks and eagles, to gather data on their migration patterns. Volunteers often observe migratory routes like mountain ridges, coastlines and land bridges, where raptors use natural updrafts to aid their flight. Organized by various individuals typically affiliated with birding groups and nonprofit organizations, hawk watching aims to provide long-term data on raptor populations and migration trends.

“What I love about watching and counting hawks is the mystery and the challenge,” says Berardi.  

Since the Zion hawk watch began, Berardi has introduced the public to the joys of watching raptors ply the sky and secured volunteers that accumulate meaningful data about the rise and fall of populations of these species. For example, over the past 25 years, the number of bald eagles migrating over Illinois Beach State Park Hawkwatch has increased, while sharp-shinned hawk numbers have declined.

These trends are reflected nationally, with numbers from other accredited hawk watches, including those at Greene Valley Forest Preserve, in DuPage County, and Fort Sheridan, in Lake County. The Hawk Migration Association of North America (hmana.org) compiles hawk watch tallies from throughout the continent and is celebrating its 50th anniversary this year.

“Hawk watching is a hobby that is not only fun but also purposeful,” says volunteer IBSP hawk counter Mark Madaus, of Roscoe. “The data we collect is used to help conservation efforts nationwide.”

In the early 20th century, hawks were erroneously thought to prey on farm animals, like pigs and sheep, leading to widespread bounties on their heads. They were shot by the thousands, contributing to the decline in bird of prey populations. Conservationists helped stop that practice but found there was more to be done after World War II, when numbers of bald eagle, osprey and peregrine falcon were declining precipitously from the effects of dichlorodiphenyltrichloroethane (DDT).

Chicago-area bird watchers including David B. Johnson, of Buffalo Grove, and Joel Greenberg, of Chicago, searched in the 1980s to watch migrating hawks and found the Lake Michigan shoreline at IBSP ideal. Berardi officially started the count in 2000 at the Illinois Beach State Park North Unit Sand Pond Area, where picnic tables, a shelter and a restroom are nearby.

During late summer and fall, migratory raptors head to their winter homes. They rely on thermals, rising columns of warm air that form when the sun heats the Earth, to help them soar and conserve energy. Hawks often avoid flying over large expanses of open water, so when they reach Lake Michigan, they get funneled into a corridor where humans can count them.

On the first hawk count in 2000, Berardi, the Sweets and Bill Wengelwski, who worked as a naturalist at the park, spent 315 hours watching and counted 2,934 raptors. “We follow specific protocols and record wind direction, air pressure and other weather variables,” Berardi says. Today, volunteers contribute more than 600 hours annually between late August and late November counting raptors. Last year, they documented 6,217 raptors at the hawk watch.

 Over the years, they have observed increases in turkey vulture and bald eagle numbers. “Flying overhead one day in 2021, we had 515 turkey vultures,” Berardi recalls. “The numbers are likely rising because there’s more people, more cars, more roadkill, and turkey vultures eat roadkill,” he says. 

“Bald eagles are making a big comeback, too,” Berardi continues. “We had an average 28 per year for the first 10 years. Now the average of 125 annually has been seen in the last 10 years.”

Conservation efforts nationwide to ban DDT, a pesticide that causes thinning of raptor eggs, have helped the eagles and another species familiar to many backyard bird watchers: the Cooper’s hawk. Adapted to finding food at feeders—specifically songbirds—Cooper’s hawks are sometimes disliked by those that observe backyard feeders, but their presence is a natural part of the food chain. “Today, populations are thriving, owing to their ability to exploit human-altered landscapes,” according to the American Bird Conservancy.

In October, it’s not uncommon to look to the sky from a suburban or even urban yard to see a turkey vulture or red-tailed hawk fly overhead, and sometimes even a bald eagle.

To see lots of migrants and more diversity, visiting a hawk watch is recommended. In mid-October, for example, sharp-shinned hawk numbers peak, with the Zion count recording 917 in a single day. However, though it’s one of the most numerous species counted during migration at many watch sites, sharp-shinned hawk numbers are declining, according to the Hawk Migration Association of North America (HMANA). Nearly half of 76 sites in North America have shown these declines. Research is needed to determine if this species is declining or changing its migratory patterns, according to HMANA.

In his fourth year counting hawks at IBSP, Madaus has been promoted to an official counter. “I have learned a ton about the different raptors, including their sizes and shapes, how different species flap and hold their wings, what months are peak migration times,” he says. “There have been many memorable days at the hawk watch. But my favorite memory has to be on September 26, 2022. It was a beautiful fall day, and we saw a few broad-winged hawks in the early morning. Little did we know that they would just keep coming, and we ended up seeing over 4,000 that day—a site single-day record. They came in large groups called kettles that would build in the sky over the lake and then stream in a straight line over us as they moved on. It was amazing to watch them build a kettle on a thermal and then stream off to take advantage of the wind.”

Sheryl DeVore has written six books on science, health and nature, as well as nature, health and environment stories for national and regional publications. Read more at SherylDeVore.WordPress.com.

SIDEBAR:

What to See and Where to Learn More About Migrating Raptors

During raptor migration season, observers might spot some hawks from their own yards by choosing an open view of the sky. The second day after a cold front with steady northwest or west winds often provides good conditions for hawk migration.

Two species commonly seen are:

Red-Tailed Hawk: This bird is brownish with a streaked belly and a dark bar between the shoulder and wrist, along with a reddish tail. Younger birds have brown-banded tails. The red-tailed hawk is visible year-round in Illinois.

Turkey Vulture: This black bird features slightly turned up wings, flying in a V shape. It displays a two-toned appearance, with the undersides of its flight feathers being much lighter than the rest of its body. The turkey vulture migrates out of the region in autumn and returns in spring.

Individuals can also visit various hawk counts to learn more. Facebook pages and websites provide directions and details on when the public can participate in these observations.

Illinois Beach State Park Hawkwatch, Lake County. Started in 2000.
Facebook.com/groups/137861126244549.

Greene Valley Hawkwatch, DuPage County. Started in 2006.
dbc2016.wixsite.com/gvhw.

Fort Sheridan Hawkwatch, Lake County. Started in 2013.
Facebook.com/groups/1466600360225361.

Boone Creek Conservation Area Hawkwatch, McHenry County.
Started spring 2024. HawkCount.org/siteinfo.php?rsite=959.