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| Northeastern Illinois is a stronghold for Henslow's Sparrow, a grassland species in decline nationally. Photo by Jackie Bowman. |
Study: Chicago region’s protected lands offer critical habitat for nesting species
(published 9-21-22)
Remember when dead bugs would plaster your car’s windshield and front bumper during summer road trips? I also recall swarms of flying pests around our porch lights, and a lot more fireflies flashing in the yard. More butterflies, too.
Insect populations are crashing, another sign of our troubled
ecological times. Birds need those bugs, of course, which is one of many
reasons why their populations are falling as well. Other downward drivers
include climate change, habitat loss, pollution, invasive species, and building
collisions.
The journal “Annual Review of Environment and Resources,”
published in May, reported that 48 percent of bird species worldwide are known
or suspected to be experiencing population declines. Only 6 percent are showing
gains, and 39 percent are stable.
We all remember the bombshell dropped by the journal
“Science” in 2019: 3 billion birds lost in the last 50 years, translating to
30% fewer birds overall. It’s noticeable, in the field and in our backyards.
Birds are struggling, no doubt, but not all of them, and not
in all places. Some good news emerged in June courtesy of the Bird Conservation
Network (BCN), a coalition of 21 conservation organizations serving the Chicago
region.
“Breeding Bird Trends in the Chicago Region 1999-2020” documents
that some local nesters, previously in decline, are stabilizing or growing in
numbers. Bellwether species such as Henslow’s sparrow (up 3.4% per year) and
red-headed woodpecker (3.3%), for example, are gaining ground.
The BCN report, based on 22 years of bird survey data, updates
the status of species that raise families in natural areas within six counties:
Cook, Lake, McHenry, DuPage, Kane and Will. Analysis was based on 30,000 bird
census surveys conducted by volunteer birders under the BCN Survey monitoring
program. The surveys occur in target habitats (grassland, shrubland, wetland
and woodland) during June and early July, prime nesting season in northeastern
Illinois.
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| The outlook for Red-headed Woodpecker has improved, thanks to effective land management. Restoration of open oak woodland and savannah habitat is helping the species. Photo by Harv Meyers. |
“People in Chicagoland tend to forget how unique it is that
we have so many green spaces concentrated in the area,” said Eric Secker, BCN president.
“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 being actively
managed and restored.”
The protected lands—about 220,000 acres of county forest
preserves municipal nature preserves and state parks—in northeastern Illinois
are critical to the health of our nesting birds. In addition, these
non-agricultural landscapes provide vital stopover habitat for migrating birds
on their way to breeding grounds farther north.
Effective habitat management is complex business, and not a perfect science. Practices aimed at helping one species may be detrimental to another. Everything is connected. Further, we don’t always know why the population of a given species is up, down or holding steady. Trends for some birds, especially secretive ones, are poorly known.
BCN’s survey work helps set priorities by identifying the
species most in need of assistance. Private and public land managers use the information
to guide their conservation efforts.
Grassland birds are high priority, which makes the upbeat
news about Henslow’s sparrow—and dickcissel, up 5.5% per year—a cause for
celebration. These species benefit from open landscapes like Springbrook
Prairie Forest Preserve in Naperville.
For the nondescript Henslow’s, whose population is declining
nationally, it’s no stretch to say that northeastern Illinois is a region of global
importance. Only an estimated 410,000 remain in the world, according to BCN.
BCN’s analysis, however, shows that populations of other
grassland specialists are falling, with bobolink, grasshopper sparrow and
savannah sparrow each down about 3%.
Birders in search of northern mockingbird and pileated
woodpecker—uncommon species in these parts—are facing slightly better odds. Both
species are trending up. In the case of mockers, geographic range expansion is
a factor.
You can see all the data for yourself, organized by habitat,
at bcnbirds.org. The trends are eye-opening, and BCN rightly expects them to be
a catalyst for action.
“Birds can be good indicators of the overall quality of the
habitat in general,” said Secker. “It’s important to remember there are lots of
areas that continue to be developed and under threat."
Copyright 2022 by Jeff Reiter. All rights reserved.