Sage grouse populations across the area have declined 80% since 1965 and nearly 40% since 2002, according to a new report from the US Geological Survey. Although the overall trend clearly shows that the population continues to decline across the entire spectrum of species, the rates of change vary regionally.
The report is the most comprehensive analysis of trends in the sage grouse population ever made and sets a surveillance framework to assess these future trends. The study can also be used to evaluate the effectiveness of efforts to protect sage grouse and analyze factors that contribute to habitat loss and population change – all important information for resource managers.
USGS scientists and colleagues developed the framework to estimate the population development of Sage-Grouse in the 11 western states where the species lives – California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming. The sage grouse is an endangered species and an indicator of the overall health of the iconic mugwort ecosystem.
Relative stability in western Wyoming
The research found that over the past few decades the rate of decline has increased in western parts of the species range, particularly in the Great Basin, while the declines have been less pronounced in eastern areas. West Wyoming was the only region that has had relatively stable sage grouse populations recently. Overall, the great sage population today is less than a quarter of the population it was more than 50 years ago.
To complete the framework, USGS and Colorado State University researchers worked with the Western Association of Fish and Wildlife Agencies, individual state wildlife agencies, and the Bureau of Land Management. Together they gathered information and created a comprehensive database of breeding areas for sage chickens. The researchers used this information to assess past and current trends in the sage grouse population in different parts of the species range.
In addition to database and population trends, researchers have developed a Targeted Annual Warning System to warn biologists and managers when local sage grouse populations begin to decline or deviate from regional trends. The research identified the most endangered breeding sites and found that the greatest risk lies on the periphery of the species range.
The report shows that there is only a 50% chance that most hatcheries, called leks, will be productive in about 60 years if current conditions persist. USGS scientists will continue to analyze information to determine the factors causing changes in breeding areas and populations, including the impact of habitat loss and degradation.
“The framework we have developed will help biologists and managers make timely decisions based on annual monitoring information,” said Peter Coates, USGS scientist and lead author of the report. “This way they can address local problems before they have a significant impact on the population.”
Thank you to the US Geological Survey for providing this news.
The judge protects nearly 1 million acres of sage and capercaillie habitat
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