Prairie birds — including Illinois' dapper bobolink — in steep decline, study says

Chicago Tribune

22-04-2025

The dapper black and yellow bobolink likes the Chicago area so much he flies here every spring from South America — a journey of about 6,000 miles.
By no means depleted, the plucky visitor goes on to dazzle the females of his species with a high-energy courtship display in which he soars over wildflower-studded fields, flapping his wings rapidly and singing a bright, burbling tune.
In the vast nature preserves surrounding the city, he is joined by the crafty eastern meadowlark, the elusive Henslow's sparrow, the stubby grasshopper sparrow, the tiny sedge wren and the gold-splashed dickcissel.
'If you go to a grassland in the Chicago area — if it's big enough — you're going to see those birds,' said Chicago Bird Alliance President Judy Pollock. 'The whole area used to look like that so it's kind of like going back in time.'
But if iconic grassland birds still appear to flourish here, the story is very different when the camera pans out across the Midwest and the Great Plains, according to the latest State of the Birds Report by scientists at U.S. bird conservation groups.
The nation's grassland birds, spread across 320 million acres in 14 states, have declined 43% since 1970, more than any other category, and are 'in crisis,' according to the report, released in March.
Overall, the study found that about a third of American bird species are of high or moderate conservation concern.
Even duck populations — previously a bright spot, with strong increases since 1970 — have trended downward in recent years, the report said.
'The bird conservation community and scientists sounded the alarm in 2019 about these declines,' said Amanda Rodewald, a professor and senior director at the Cornell Lab of Ornithology's Center for Avian Population Studies.
'We're a little over five years out and we're seeing they're becoming steeper — some of these trends. We know this is happening. We're now showing we have tools and data sets (that can help) managers and decision-makers to know specifically where they need to direct some conservation. What we need is the will to act.'
The study encourages practices such as coastal restoration, conservation ranching and seabird translocation, or transporting birds to locations where they are likely to thrive.
For grassland birds, which are losing 1 million to 2 million acres of habitat annually in the Great Plains, the study highlights solutions such as improved grazing practices for cattle and sheep, invasive plant removal, investment in grassland conservation and converting low-quality cropland to grassland.
The landmark 2019 study, which found that the North American bird population had dropped by nearly 3 billion since 1970, focused on the nation as a whole, while the new study focuses on birds that require certain specific habitats, such as forests and coastlines.
Those birds are better indicators of change in a particular habitat because they don't just dip in and out of it — they depend on it for survival.
In the case of grassland birds, including those in Illinois, the news isn't good. The study says birds that need grassland habitat are in crisis.
One measure the study looked at was 'tipping point' species status, which signals that a bird has lost more than 50% of its population within the past 50 years.
Shorebirds had the most tipping point species, with 19. Grassland birds had eight tipping point species, including the plucky bobolink and another Chicago classic, the Henslow's sparrow.
The bobolink was listed as an 'orange-alert' tipping point species, second only to the 'red-alert' category. Orange-alert status is for birds showing 'long-term population losses and accelerated recent declines within the past decade.'
The Henslow's sparrow was listed as a 'yellow-alert' with 'long-term population losses but relatively stable recent trends' and 'continued conservation efforts needed to sustain recovery.'
A total of 9% of the breeding population of Henslow's sparrows and 5% of the breeding population of meadowlarks are in Illinois, according to Jim Giocomo, the American Bird Conservancy's central region director.
The study's findings are important in part, he said, because humans live in the same environment as birds.
'Birds are literally our canary in the coal mine,' he said. 'The bird needs the same stuff we do but reacts to changes in the environment faster.'
Water availability, air pollution, chemicals and the decline of insect populations all can affect birds.
The eastern meadowlark, a fairly common sight for grassland birders in the Chicago area, wasn't singled out for concern in the study. But the LeConte's sparrow, lark bunting and western meadowlark — all grassland birds — were among the species that experienced the largest declines in the Midwest and Great Plains.
The LeConte's sparrow migrates through Illinois, and some western meadowlarks summer here. Lark buntings are generally found farther west.
The Chicago-area birding community has been working to restore grassland habitat for at least 20 years, according to Pollock, and forest preserve districts in and around Chicago have made good progress.
The Forest Preserves of Cook County, for instance, has removed trees and connected pieces of land to create sprawling prairies for grassland birds, which nest on the ground.
'They need really large areas to hide their nests from predators,' Pollock said. 'One hundred acres is small for them. They really want 1,000, 2,000 acres.'
The big grassland preserves in the region include Bartel Grassland and Bobolink Meadow near Tinley Park, Orland Grassland near Orland Park, Busse Woods near Elk Grove Village and Paul Douglas Preserve in Hoffman Estates.
A 2022 study by the nonprofit Bird Conservation Network found that dozens of birds, including the Henslow's sparrow, are doing surprisingly well in Chicago — likely because of the region's many parks and nature preserves, which cover nearly 10% of land in the six-county area.
Of 104 key species tracked in the study, 56% had stable or increasing populations in the Chicago region, while only 37% were stable or increasing in other areas of the state.
At the time, only about 410,000 breeding Henslow's sparrows remained in the world, and the birds were declining nationally.
However, the conservation network study found the birds were up an average of 3.4% per year in the Chicago area.
The bobolink was a different story, with the study finding the local bobolink population was down 2.9% per year since 1999.
Among the possible explanations: A lot of restored grasslands in the area tend to be dominated by tall grasses, and bobolinks may prefer a mix of grasses and flowering plants, Bird Conservation Network President Eric Secker told the Tribune in 2022. It was also possible that an international decline in insects, which is increasingly of concern to scientists, may have been reducing the birds' food supply.
Lastly, the problem may not have been limited to this region — or even this country, he said. Bobolinks are poisoned by farmers in Central and South America, where the birds feed on crops.
Solutions to the grassland bird decline vary among regions, although all rely on increasing or improving habitat. In the Great Plains, Rodewald highlighted the work of the Bird Conservancy of the Rockies, which encourages voluntary conservation by farmers and ranchers.
'People rely on the land for their livelihoods, and so any approaches that we're using to preserve birds in those areas needs to be really grounded in voluntary conservation measures,' Rodewald said.
In Illinois, 'agricultural intensification,' in which farmers squeeze more production out of their land, is a major contributor to grassland bird decline, she said. Agricultural intensification means bigger farms, larger single-crop areas, less rest for the land, fewer hedgerows and more chemicals.
Among the potential solutions: The government can give farmers financial incentives to return land to a more natural state, as in the farm bill's conservation reserve program.
The farm bill is a comprehensive package of legislation that sets agriculture and food policy and is supposed to be updated every five years. The 2018 farm bill has been extended twice as Republicans and Democrats argue about what should be included.
Bobolink-conscious management of hay fields also can help in Illinois, Pollock said. The birds lay several sets of eggs in the course of a summer, and mowing can prove fatal to the young.
'They're crunching up lots of baby bobolinks, and other grassland birds,' Pollock said.
The solutions include mowing in May, which discourages nesting. That's a good approach when conditions are right, Pollock said, but sometimes it's too wet to mow.
Rodewald said data on birds has improved, thanks to the efforts of volunteers and advances such as the popular eBird app, which allows everyday birders to submit detailed reports on their sightings.
'It's really adding to our ability to detect and diagnose population changes — and that, fundamentally, allows us to respond to them in ways that are more proactive, more cost-efficient and more effective on the ground,' she said.
For example, scientists can use eBird data to determine where installing a solar array is least likely to affect a sensitive bird population, or where a conservation measure — say, adding more trees — can benefit humans as well as birds.
'Despite the bad news, I think that because we have more information than ever and knowledge is power, we do have reason to hope,' Rodewald said.