North American birds are vanishing faster in three farming regions

Bird losses speed up across the U.S.

North American bird populations have dropped by about 15% since 1987, and a new study shows the losses are picking up speed.

The research, published Feb. 26, 2026, in the journal Science, is the first to pinpoint regions where bird declines are accelerating.

A team led by François Leroy, a postdoctoral scholar at Ohio State University and the Czech University of Life Sciences, tracked 261 species across more than 1,000 survey routes.

Nearly half of those species showed significant population drops.

Thousands of volunteers collected the data

The researchers pulled their numbers from the North American Breeding Bird Survey, a monitoring program that has tracked bird populations since 1966.

Every spring, thousands of trained volunteer birders run standardized counts along fixed routes across the country.

For this study, the team analyzed data from 1,033 routes covering 261 species, 54 bird families, and 10 habitat types.

The data stretched from 1987 to 2021, giving researchers more than three decades of trends to work with.

Three regions stand out from the rest

The Midwest, California, and parts of the Mid-Atlantic showed the sharpest acceleration.

Bird populations in these areas were already shrinking in the late 1980s, but now they’re losing birds even faster than they were 30 years ago.

The Midwest hotspot covers a huge stretch of the nation’s farming heartland.

These are the first regional hotspots of accelerating bird decline ever identified in a peer-reviewed study. The common thread?

All three overlap heavily with intensive agriculture.

Farming intensity tracks with faster losses

Agricultural intensity turned out to be the strongest predictor of where bird losses are speeding up. The researchers measured it three ways: cropland area, fertilizer use, and pesticide use near survey locations.

All three indicators run closely together, and areas with higher agricultural intensity were more likely to show accelerating declines. About 40% of U.S. land goes to agriculture, so the footprint is enormous.

The findings raise big questions about which specific farming practices hurt birds the most.

Researchers found a pattern, not proof

The team stressed that their findings show a strong statistical link, not direct cause and effect.

They said they can’t separate the individual effects of cropland expansion, fertilizer, and pesticides on bird populations.

Leroy noted that the consistency of the pattern across both smoothed maps and raw model outputs makes it hard to dismiss. But more research is needed to figure out exactly which farming practices do the most damage.

That distinction matters for shaping future policy.

Heat hits hard, but farming drives acceleration

Rising temperatures were the strongest predictor of overall bird population decline, especially in already-hot southern states like Florida and Texas.

But temperature change wasn’t the main force behind the acceleration of those losses. Farmland often lacks shade trees, so it heats up more than natural areas, which may pile extra stress on birds.

Co-author Marta Jarzyna said the acceleration of declines ties mostly to agricultural practices, while the broader decline links more closely to warming.

Common species are losing ground fast

Some of the hardest-hit birds are ones most Americans would recognize. The common grackle, European starling, and red-winged blackbird all showed steep drops.

The red-winged blackbird stood out with one of the sharpest declines and one of the strongest accelerations. Twice as many species showed speeding-up losses compared to those slowing down.

The pattern cut across many different types of birds from different habitats, which suggests the problem runs deep rather than affecting just one group.

An ornithology lab set the alarm in 2019

This isn’t the first warning.

A landmark 2019 study led by Ken Rosenberg of the Cornell Lab of Ornithology found that North America had lost 2.9 billion birds, about 29%, since 1970.

That research covered 529 species across the U.S. and Canada and found losses in nearly every habitat type.

Grassland birds took the worst hit, losing more than half their populations since 1970. The new 2026 study goes further by showing the rate of loss itself is climbing.

Birds do more than sing

Birds play a bigger role than most people realize. They eat insect pests, which cuts the need for chemical pesticides in both natural and farm settings.

They carry seeds across long distances, helping plants spread and forests recover. They cycle nutrients between habitats and feed larger wildlife up the food chain.

Rosenberg put it bluntly: if the environment can’t support healthy populations of even the most common and adaptable species, that’s a strong sign it’s also harmful to people.

Some species made strong comebacks

Not all the news is grim. Waterfowl populations have grown by more than 50% since the 1970s, and raptors like bald eagles and ospreys have staged major recoveries.

Those comebacks followed targeted conservation efforts, including the ban on the pesticide DDT, endangered species protections, and billions of dollars invested in wetland conservation through programs tracked by the North American Breeding Bird Survey.

One small pocket of land just north of the U.S.-Canada border was the only region in the new study where overall bird numbers actually went up, though researchers aren’t sure why.

Leroy says birds can bounce back

Leroy said biodiversity is dynamic. If habitats are restored and chemical pressures come down, birds and insects can return within years to decades.

Farmers manage a huge share of the American landscape, which puts them at the center of any effort to reverse the trend.

The researchers also pointed out that agricultural workers are the people most exposed to the same chemicals affecting ecosystems.

Tracking how fast populations change, not just how much, could help catch problems before they get out of hand.

Speed of loss tells the real story

A steady decline is bad enough. But when losses grow larger year after year, it means the situation is getting worse faster.

Birds are among the most closely watched wildlife groups, which makes them useful early indicators of broader environmental health.

The study’s authors said looking at the speed of change, not just the direction, may give a clearer picture of what wildlife faces.

The pattern in North America mirrors findings in Europe, where agricultural intensity has also been linked to accelerating bird losses.

This article was created with AI assistance and human editing.

Read more from this brand:

• Americas Trees Are Making a Quiet Comeback in 60 Percent of Counties
• Trump wants a hotel CEO to manage Yellowstone, Grand Canyon, and all U.S. parks
• 13 zones inside national parks where most humans are banned from entering