Even in protected areas, birds are disappearing from America’s prairies, and unpredictable weather isn’t helping.
That’s the takeaway from a new study by researchers at Michigan State University, Oklahoma State University, and the Minnesota Department of Natural Resources.
The study, published in the journal Ecological Applications, analyzed 16 years of bird survey data at 40 tallgrass prairie sites in western Minnesota.
The sites were all protected areas — a mix of state parks, wildlife management areas, and private conservation easements.
Researchers returned to the same spots again and again between 2008 and 2023, watching and listening for what bird species showed up during the summer breeding season.
The results suggest that bird nesting season in the Minnesota prairie isn’t quite what it used to be.
Visitors might still hear the buzzy song of the Dickcissel, for example, or see the tuxedo-like plumage of the Bobolink. But the long, drawn-out whistle of Upland Sandpiper, which flies all the way from South America, has faded. And birds like the Savannah Sparrow and the Sedge Wren have become harder to spot.
While grassland specialists fared worse than birds that use multiple habitats, even some generalists, such as Mourning Doves that coo under bird feeders and Red-winged Blackbirds that perch on fence posts, are less common today than they were 15 to 20 years ago.
“I've been a birder since I was a kid, and I think of some of these species as pretty widespread,” said lead author Neil Gilbert , who did the research while working as a postdoctoral fellow at Michigan State University.
“That means these losses aren’t just happening for rare species,” added Gilbert, now an assistant professor at Oklahoma State University. “It's common birds that you drive past every day and see in your backyard.”
Overall, for the 33 species monitored in the study, the likelihood of spotting birds in the protected areas dropped by 22% over the 16-year period.
That grassland birds are struggling came as no surprise. A landmark 2019 study led by the Cornell Lab of Ornithology estimated that the number of birds in the U.S. and Canada has fallen by nearly 30% in the last half-century.
That’s 3 billion birds lost. The same study found that grassland birds were among the hardest hit, with their populations cut in half since the 1970s.
But the new study reveals that grassland birds are disappearing even from supposed strongholds.
“These birds are declining despite being in exceptional habitat,” said study co-author Chris Jennelle , a biometrician with the Minnesota Department of Natural Resources.
“The study sites in Minnesota are some of the best prairies we have left in the U.S.,” he added. “Seeing these patterns is definitely worrisome.”
To figure out what might be driving the losses, the team analyzed several factors, including the amount of grassland habitat and how fragmented it was, along with whether the breeding season was cooler or hotter than normal, or wetter or drier.
They found that climate played a role for some species, but the effects weren’t homogeneous: unusually warm or wet conditions that accelerated declines for some species gave other species a boost.
But as a whole, birds in these grasslands continued to decline no matter how big or small their patch of grassland, or whether they had plenty of interior space or were more exposed to edges and pressures outside the protected area.
This doesn’t mean that conserving what’s left of America’s grasslands is no help to birds.
“We’re not saying that protecting land is pointless,” Gilbert said. “But if you have a little postage stamp of a preserve located in a sea of cropland, that may not be enough.”
When European settlers first started flocking to Minnesota in the 19th century, a third of the state — some 18 million acres — was covered by prairie. Today, less than 2% of those original prairies remain, most of it having been converted into pastures and farms.
It may be that the birds that inhabit these areas today are still paying for these historical habitat losses, the researchers said — essentially living on borrowed time.
The phenomenon, known as extinction debt, could explain the ongoing declines. If so, then simply creating new reserves or expanding grassland habitat within existing ones “is probably not going to cut it, especially as climate conditions continue to change,” said senior author Elise Zipkin , director of MSU’s Ecology, Evolution, and Behavior program.
The protected areas in the study ranged in size from roughly two city blocks to slightly bigger than Central Park.
“The patches of prairie that remain may simply be too small or isolated to safeguard birds from further decline,” Zipkin added.
“There are probably other contributing factors at play as well,” Jennelle added.
Pesticides may be killing the insects that birds feed to their young, for example.
Living inside protected areas does not automatically protect birds from things happening outside of the protected areas, such as in their overwintering and migration ranges — which means curbing these losses may require coordinated international efforts.
Another solution is working with farmers and ranchers and other landowners, since more than 80% of the habitat that grassland birds need is privately owned.
“We have to expand our horizons a little bit and think about what else we can be doing to protect birds and other wildlife,” Gilbert said.
This research was supported by grants from the National Science Foundation (NSF DEB-2213565 and NSF Postdoctoral Research Fellowship in Biology 2208894) and the Office of Conservation Investment - State Wildlife Grants Program of the U.S. Fish and Wildlife Service.
CITATION: "Limited capacity of habitat features to buffer grassland bird declines," Neil A. Gilbert, Peter J. Williams, Daren J. Carlson, Robert M. Dunlap, Mike Worland, Christopher S. Jennelle, Elise F. Zipkin. Ecological Applications, Aug. 25, 2026. DOI: 10.1002/eap.70298
Ecological Applications
Observational study
Animals
Limited capacity of habitat features to buffer grassland bird declines
25-Aug-2026