‘Canary in the coal mine’
Many North American grassland bird species headed toward possible extinction, raising alarm
WPOTTER, Neb. hen Reed Cammack hears the first meadowlark of spring, he knows his family has made it through another cold, snowy winter on the South Dakota prairie. Nothing’s better, he says, than hearing the birds light up the area with song at sunrise.
“It’s part of the flora and fauna of our Great Plains and it’s beautiful to hear,” says Cammack, 42, a sixth-generation rancher who raises cattle on 10,000 acres of native grasslands.
But the number of birds has dropped steeply over the years, despite seemingly ideal habitat “and I don’t know for sure why,” says Cammack’s 92-year-old grandfather, Floyd.
North America’s grassland birds are deeply in trouble 50 years after adoption of the Endangered Species Act, as habitat loss, land degradation and climate change threaten what remains of a once-vast ecosystem from Canada to Mexico.
Over half their overall population has been lost since 1970, and several species are heading toward possible extinction.
“Birds are the canary in the coal mine,” says Amanda Rodewald, senior director of the Center for Avian Population Studies at Cornell University’s ornithology lab. “They’re an early warning of environmental changes that also can affect us.”
The lesser prairie chicken, which has declined by more than 90%, is the only grassland bird federally listed as endangered, in part of its range. Congress voted to delist it in an effort led by Republicans who say the protections hinder oil and gas drilling, though environmentalists hope President Joe Biden will veto the measure.
But more than half a dozen other grassland birds have lost 50% or more of their breeding population and could lose another 50% in the next half-century, according to a 2022 report. They include: the Sprague’s pipit, a northern grassland songbird, that’s lost more than 75% of its population since 1970. The chestnut-collared longspur, which lives in the northern shortgrass prairie and sings as it flies. The Henslow’s sparrow, which barely sings at all. And the bobolink, known for its robust songs and long-distance travels to South America. The 38% — 293,000 square miles — of historic North American grasslands that remain are threatened by intensive farming, urbanization and the rapid spread of trees once held at bay by periodic fires.
Still, much is unknown: Where do birds stop during migration and for how long? What’s happening on their wintering grounds and how many birds return from their winter territory? If birds must travel great distances to find suitable breeding habitat, does that affect breeding success?
“Where along that full life cycle both in time and space are these birds suffering the most?” says Andy Boyce, a research ecologist at the Smithsonian’s Migratory Bird Center who studies the Sprague’s pipit. “We need to figure out a lot of this before we can even start to prioritize where conservation actually needs to take place.”
Researchers aim to learn more with the help of radio telemetry receivers being installed across the Great Plains to help track birds from Canada to Mexico’s Chihuahuan desert.
When a bird fitted with a tiny transmitter flies within 12 miles of a receiver — mounted on towers and other structures — information is collected electronically by researchers.
Researchers are about halfway to building 150 or more receivers, says Matthew Webb, who leads installation efforts for the Bird Conservancy of the Rockies. He says it’s “extremely important to get adequate coverage,” to fill knowledge gaps about bird movements.
Meanwhile, biologists are sharing data and using sophisticated computer modeling to determine the biggest threats. And they’re working with farmers and ranchers to implement practices that ensure survival of livelihoods and native birds.