Michael Gennaro

SEATTLE (CN) — The U.S. Fish and Wildlife Service designated the Mount Rainier white-tailed ptarmigan a threatened species under the Endangered Species Act Tuesday, capping off years of environmentalists' petitions and legal actions aimed at safeguarding the bird.

Recognizing the bird's populations have suffered due to habitat loss and degradation stemming from climate change, the agency also committed to reevaluating the bird’s critical habitat, a move that raises hopes for the preservation of the environments essential for the ptarmigan's survival.

“Rising temperatures associated with climate change are expected to have direct and rapid impacts on individual birds. Changing habitat conditions, such as loss of suitable alpine vegetation and reduced snow quality and quantity, are expected to cause populations to decline,” the Fish and Wildlife Service wrote in its decision.

The white-tailed ptarmigan is the smallest member of the grouse family. It has evolved to adapt to harsh, high-altitude mountain environments: Feathered, snowshoe-like talons and seasonally changing plumage — along with the ability to gain body mass during the winter — help the species survive in frigid temperatures.

The Mount Rainier white-tailed ptarmigan is a year-round resident of alpine zones above the treeline, stretching from southern British Columbia to Mount Adams in southwest Washington.

In winter, the birds depend on dry, fluffy snow to insulate themselves against the cold. Climate change has intensified rain-on-snow events, forming hard crusts that are unsuitable for the ptarmigan’s burrowing needs.

Summers present another challenge: The birds favor wet meadows nourished by melting snowfields and glaciers, which are rapidly diminishing. And higher temperatures brought on by climate change are pushing the tree line — and the ptarmigans — further up the mountainsides, shrinking their habitats and leaving the birds with increasingly limited space to survive.

“It is unlikely that the Mount Rainier white-tailed ptarmigan will adapt to the changing climate by moving northward because alpine areas north of the subspecies’ current range are expected to undergo similar impacts due to climate change and any potential connectivity to areas north of the current range is expected to decline,” the Fish and Wildlife Service wrote in its decision.

Ptarmigans exhibit signs of stress at temperatures above 70 degrees Fahrenheit, making them particularly vulnerable as global temperatures rise.

“These beautiful winter birds are immediately threatened by our warming world,” said Noah Greenwald, the endangered species director at the Center for Biological Diversity. “Like a canary in a coal mine, the ptarmigan is telling us that we’re losing the snowpack that keeps Washington’s streams cool and flowing throughout the summer.”

The Center for Biological Diversity first petitioned for the ptarmigan’s protection in 2010. Despite the group underscoring the urgency of their situation, it took 14 years for the U.S. Fish and Wildlife Service to grant the needed protections, far exceeding the two-year timeline mandated by law.

“Our world is changing and changing fast,” Greenwald said. “The Service continues to move at a glacial pace to protect species like this highly imperiled bird. The agency desperately needs an overhaul to make sure we don’t lose so many vulnerable plants and animals.”