Landmark Study Underscores Global Importance Of Chicago Region To Dozens Of Breeding Bird Species

Comprehensive data set shows mixture of successes and declines across habitat types

CHICAGO, IL June 7, 2022A 22-year study of breeding birds shows that northeastern Illinois is a stronghold for breeding birds and of global importance for several key avian species. Breeding Bird Trends in the Chicago Region 1999-2020 provides an update on the status of more than 100 nesting species across grassland, shru-bland, wetland, and woodland habitats. The report shows that some breeding bird species are stable or expanding, while others face declines.

The Bird Conservation Network (BCN), a coalition of 21 conservation organizations dedicated to the preservation of birds and the habitats they need to survive, collected the data from managed lands within six counties: Cook, Lake, McHenry, DuPage, Kane, and Will. During the 22-year analysis period, volunteer monitors conducted nearly 30,000 surveys across more than 2,000 points annually in June and early July. The surveys followed strict protocols for breeding bird point counts in target habitats in county forest preserves, state parks, and other managed lands encompassing the Chicago Wilderness Region.

“People in Chicagoland tend to forget how unique it is that we have so many green spaces concentrated in the area,” said Eric Secker, President of the Bird Conservation Network. “We found that a lot of birds in Chicago are doing better than the rest of the state and elsewhere in the nation because we have so much land that’s being actively managed and restored.”

The study’s findings reveal a dynamic landscape. For example, birds becoming more common include Sandhill Cranes, Pileated Woodpeckers, and Northern Mockingbirds, while birds previously in decline appear to be stabilizing or showing growth, such as Red-headed Woodpeckers and Henslow’s Sparrows. At the same time, many species are showing distressing declines, such as Ovenbirds, Bobolinks, and certain other grassland species.

“Birds can be good indicators of the overall quality of the habitat in general,” Secker said. “It’s important to remember there are a lot of areas that continue to be developed and under threat.”

One species that stands out is the Henslow’s Sparrow, a secretive bird of dense weedy fields. Henslow’s Sparrows are declining nationally, but they are expanding in northeastern Illinois, by 3.4% per year in BCN’s analysis. The species has benefited from the restoration and creation of tallgrass prairie.

“In no place in the world will you find a greater concentration of Henslow’s Sparrows than in north- eastern Illinois,” said Jim Herkert, former Executive Director, Illinois Audubon Society. “It is a globally important landscape for this bird.”

Species analyzed had a minimum of 10 sightings over the period, and important species that did not meet this threshold were therefore not included in the survey results, although they remain of conserva-tion interest to the region. More than 200 volunteers participated in the survey over the years.

“The Bird Conservation Network has been a pioneer in using targeted surveys to better understand birds in a region,” said Chris Wood, Project Leader, eBird, Cornell University Lab of Ornithology, “and influence the way that areas are managed to ultimately increase the populations of species that are declining elsewhere.”

The decline in Bobolinks may be due to their preference for wetter fields, while some practices favor the conversion of hayfields and fallow fields to tall prairie species. Ovenbirds nest in the heavy leaf litter of woodlands and may be declining due to clearing and burning.

BCN hopes the study is a catalyst for action, particularly among researchers and land managers. Bird numbers overall are believed to have declined by 30% in the past 50 years. Birds face negative impacts such as habitat loss, building collisions, invasive species, the decline of insect populations, pollution, and climate change.

To view the full dataset and additional background and analysis, visit

Breeding Bird Trends in the Chicago Region 1999-2020

The Bird Conservation Network (BCN) is a coalition of 21 conservation groups, of which Lake Cook Audubon is a member, includes Audubon chapters, bird clubs, ornithological societies, and conservation organizations sharing an interest in the preservation of birds and the habitats they need to survive. The groups’ members total more than 35,000 people living primarily in the Chicago area but also throughout Illinois, northwestern Indiana, and southern Wisconsin.

Count Breeding Birds in June for Annual Survey

BCN – the Bird Conservation Network – is a volunteer organization of 21 conservation groups across Northeast Illinois. BCN is dedicated to the preservation of our endemic breeding bird species. Lake Cook Audubon is a charter member of BCN.The centerpiece of BCN’s volunteer work is coordinating annual surveys of breeding birds at selected preserves across the region. For the past 20 years, these surveys have provided vital information for understanding the population trends of the key species we all care about. Most importantly, this detailed data is used by forest preserve districts and other land managers to identify their properties’ most critical preservation and restoration needs.

BCN and the county preserve land managers want to expand this valuable monitoring program to cover additional sites. BCN is looking for birders to help launch the expansion with the June 2022 bird count survey.

The Details:+ Birders are invited to volunteer

Since the count data is used for habitat conservation planning and scientific studies, volunteers with at least three years of birding experience are needed. You don’t need to be a super birder to volunteer, but bird survey participants should be able to identify birds breeding in our area by sound as well as by sight.You can volunteer to monitor alone, or you can team up with a birding friend to monitor together. Only one birder in a team needs to be adept at identifying birds by sound.

+ What volunteers do
Monitoring entails two bird survey visits in June at one of the selected preserves in our area. As a monitor, you go to pre-determined points throughout your chosen preserve and count the number of birds seen and heard for ten minutes at each point.   You enter your results into a special Forest Preserve app (mECO) on your smartphone as you monitor at each point.  The app automatically records weather conditions and also prompts you for questions about the foliage.

Count Breeding Birds in June for Annual Survey
+ To volunteer or if you have any questions, contact:

Properties Where Volunteer Monitors Are Still Needed:
Count Breeding Birds in June for Annual Survey
All are in Lake County:

  • Lakewood (4 – 5 volunteers needed)
  • Cuba Marsh (2 volunteers needed)
  • Grassy Lake – near Lake Barrington
  • Independence Grove – Need 1 additional volunteer
  • Fort Sheridan
  • Greenbelt FP