To Reverse Common Bird Declines, Conservationists Will Need to Think Bigger

Growing up on the rolling pastures of River Valley Farm in New Jersey, Bryce Cotton remembers hearing birdsong across the cattle ranch—the cries of kestrels and the trills of Killdeers. That started to change when his family leased the land out for conventional row crop farming. By the time Cotton took over the property nearly a decade later, the soil was depleted and the chorus had gone quiet.

Across a variety of landscapes, the sights and sounds of these and many other familiar birds, from finches to blackbirds to sparrows, are similarly waning. Per a recent assessment by the International Union for Conservation of Nature, 61 percent of all avian species are declining globally, largely due to loss of habitat. And mounting evidence shows that rare species in far-flung places aren’t the only ones struggling. Common birds—those with relatively large, widespread populations—are facing some of the steepest downturns.

In North America, a 2019 study offered a powerful wake-up call. It estimated that, since 1970, the continent had lost nearly 3 billion birds, accounting for more than 1 in 4 birds overall. Research since has further documented common birds’ downturn: In March, for example, the State of the Birds report pointed out 46 common species in steep decline. In July, a separate analysis found that abundant species saw the steepest drops in recent decades. At the same time, some rare and imperiled bird populations actually increased as targeted conservation efforts paid off.

The data underscore the delicate balancing act for supporting birdlife. “Often in conservation, we focus on the most vulnerable species,” says Nicole Michel, director of quantitative science at Audubon. “We need to keep doing that. But we also need to remember that these common birds need help too.”

Some of the biggest wildlife wins from past decades occurred when scientists pinpointed one pressure point causing declines. The insecticide DDT, for example, nearly wiped out Bald Eagles, Peregrine Falcons, and Brown Pelicans, among others. After DDT was largely banned in the United States in 1972, those birds began to recover and are thriving today. That was a specific problem with a specific fix. “That’s not what’s happening now,” says Ken Rosenberg, conservation scientist emeritus at the Cornell Lab of Ornithology.

Today widespread resident and migratory birds face a slew of varied, intersecting threats across regions, such as pesticide use on farmlands, glassy buildings in cities, and accelerating climate change worldwide. But the largest factor is human land use: Expanding agriculture, increasing development, and other shifts have taken away or degraded crucial habitat that abundant birds need to find food or build nests.

This means helping common birds “is a harder challenge in a lot of ways,” says Princeton University ecologist Gates Dupont, who led the July study. While individual actions such as seeding yards with native plants and keeping cats indoors play an important role, conservation with landscape-wide reach is also critical. “We need to meet the scale at which humanity is disrupting or disturbing the environment,” Dupont says.

In the United States, efforts to work with private landowners to improve forest health and restore grasslands hold some of the biggest potential, experts say. For example, research shows that plots of land in Audubon’s Conservation Ranching program—which encourages practices such as rotational grazing to maintain grassland ­habitats—host higher bird density than average. “It shows it can be done,” Michel says. “It is being done.”

To scale up, conservationists are using improved data and modeling to identify habitats that offer the biggest benefits. “We have an opportunity to really think strategically here,” says Brooke Bateman, Audubon’s senior director of climate and community science. A recent study she led identified areas in the United States where restoring ecosystems can boost birds, carbon storage, and human well-being all at once. Those priority zones include 312 million unprotected acres, or 14 percent of U.S. lands, where conservation would offer all three rewards.

Ultimately, taking steps to support abundant birds—which provide essential services such as dispersing seeds and pollinating plants—helps wildlife, people, and the broader environment. Cotton, in New Jersey, is discovering this himself. Since taking over his family land in 2007, he’s worked with local conservation groups to restore native grasses and added nest boxes for Tree Swallows. The birds reduce flies that bother his cattle, and the return of kestrels, along with a host of other species, has transformed the ranch into a local birding hotspot. “When you’re out there,” Cotton says, “everything is very much alive.”

This story ran in the Winter 2025 issue as “Common Cause.” To receive our print magazine, become a member by making a donation today.