The Search for One of North America’s Rarest Birds

In the middle of Alaska’s Bering Sea, St. Matthew Island and its much smaller neighbor Hall Island are among the few specks of land amid hundreds of square miles of water. These uninhabited volcanic isles host an impressive array of Arctic birds, including one of North America’s most enigmatic species: the McKay’s Bunting, which breeds only here. Last summer a team of scientists made a rare expedition to St. Matthew, voyaging more than 500 miles from the Aleutian Islands to conduct the third-ever McKay’s Bunting survey. They had a week to scour an island six times the size of Manhattan for the songbirds—a critical step for investigating what they worry is an ongoing population decline. 

Scientists first surveyed McKay’s Buntings in 2003. When they returned in 2018, they discovered the species had declined by 38 percent. The startling results convinced the researchers that they couldn’t wait another 15 years to come back, says Steve Matsuoka, a U.S. Geological Survey biologist who participated in both surveys. On the expedition last June, Richardson, Matsuoka, and seven other biologists arrived to find cold, windy spring conditions had delayed nesting. Every morning, the team took inflatable skiffs from the U.S. Fish and Wildlife Service vessel Tiĝlax̂ to St. Matthew, where over eight days they walked and snowshoed across more than 100 miles of icy, rocky, and grassy terrain. “It’s the epitome of remoteness,” Matsuoka says.

The snow that persists on St. Matthew’s slopes in early June is the perfect cover for the nearly pure white McKay’s Bunting, a species that likely diverged from the much more widespread Snow Bunting when a small group was marooned during a recent ice age. Each spring, McKay’s migrate from the remote western coast of Alaska to nest in the island’s rock crevices, piles of driftwood, or even the bones of whales that have washed ashore.

Beyond these facts, scientists know little about the birds, says USGS wildlife biologist Rachel Richardson. There’s no doubt, however, that their small population and limited breeding range render the stunning songbirds particularly vulnerable to environmental changes, making surveys essential to assessing their risk of extinction.

Last year, the team encountered buntings in a frenzy of breeding activity: females gathering nesting material and males squabbling over territory and singing. The team’s analysis is ongoing, Matsuoka says, but their early impressions were worrisome: “There’s been no obvious rebound.”

St. Matthew is home to an impressive array of other wildlife. Hundreds of thousands of seabirds, including auklets, kittiwakes, and Northern Fulmars nest on the towering columnar basalt rock formations. On the tundra, red and Arctic foxes stalk a species of vole found only on St. Matthew and Hall. Yet global warming is increasingly putting this rich biodiversity at risk, Matsuoka says, noting that the Bering Sea region is an epicenter of climate change impact. He points to the Common Murre, long among the most prolific nesting birds on St. Matthew, as one sobering example.

An unprecedented marine heat wave a decade ago displaced or killed the small, cold-water fish they eat. Four million murres, half the Alaskan population, starved to death in less than two years—and the species hasn’t rebounded.

Climate change may be affecting the bunting, too, but scientists can’t yet pinpoint the causes of its decline. An ongoing project to map land cover could reveal the habitat types the birds are using, and Matsuoka and Richardson hope to gain more insight by studying the birds on the mainland during the nonbreeding season.

It’ll likely be at least five years until the team can fund and schedule its next McKay’s survey on St. Matthew, though. Until then, the bunting will press on, isolated in its little corner of the globe. 

This story originally ran in the Spring 2025 issue as “Search Party.” To receive our print magazine, become a member by making a donation today.