George Fenwick, the organization's president, said the numbers of the birds have dramatically diminished during recent decades, and the expansion of energy developments that threaten the species' sagebrush habitat are continuing.
"While there have been legitimate, good-faith conservation efforts undertaken in the last couple of years by federal, state and private interests to help the Greater Sage-Grouse, by the same token there is also absolutely no mistaking that the path we are on will lead to fewer and fewer birds," Fenwick said in a statement. "More needs to be done. The species needs to be fully protected, and (an Endangered Species Act) listing is the best way to achieve that."
The Fish and Wildlife Service said it's reviewing the status of the bird and is expected to soon announce its findings.
The ABC said the species has lost 30 percent of its number during the past 25 years.
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