Study: Climate change threatens sage grouse habitat

SIOUX FALLS, S.D. – A warming climate could significantly reduce the amount of greater sage grouse habitat in portions of Wyoming, a key stronghold for the troubled bird species, government scientists concluded in a new study.

The chicken-size grouse has seen dramatic declines in recent decades due to disease, oil drilling, grazing and other changes across the bird’s sagebrush habitat.

U.S. Geological Survey scientists said a warming climate could become an even greater risk, potentially reducing grouse nesting habitat in southwestern Wyoming by 12 percent by 2050.

The findings were published in the journal Ecological Indicators. Scientists analyzed past climate patterns across 3,200 square miles and compared that with rain and snowfall projections to predict future conditions.

As precipitation levels drop in coming years, the study said, sagebrush will become more vulnerable to fire, insects and disease. Some areas with the plants will convert to bare ground.

The study centered on an area of the sagebrush ecosystem that is considered among the least vulnerable to climate change. That suggests other areas occupied by sage grouse could see even greater change, the scientists said.

“Historic disturbances of fire, development and invasive species have altered the sagebrush landscape, but climate change may represent the habitat’s greatest future risk,” said Collin Homer, a USGS scientist based in Sioux Falls, South Dakota, and the lead author of the study.

The team of USGS researchers examined warming impacts on areas as small as a quarter of an acre, which Homer said could help land managers better plan for the future.

The U.S. Interior Department is to decide this fall if the birds should be protected under the Endangered Species Act. They occupy 290,000 square miles of sage brush habitat in California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington, Wyoming and portions of southern Canada.

Population estimates for greater sage grouse range from 100,000 to 500,000 birds.

Grouse numbers are down at least 30 percent since 1985.