ÃÛèÖÖ±²¥ environmentalists say they have filed a notice of intent to sue and compel the U.S. Fish and Wildlife Service to expand critical habitat for ÃÛèÖÖ±²¥'s highly endangered Mount Graham red squirrel.
The Center for Biological Diversity and Maricopa Audubon said in a Tuesday news release that only 75 of the squirrels are still alive.
The federal wildlife agency did not immediately respond Tuesday evening to a request for comment.
The center says the animal's critical habitat, including spruce-fir forests above 9,200 feet in a remote part of southeastern ÃÛèÖÖ±²¥, has been destroyed by construction of mountaintop telescopes, wild fires and fires set intentionally to protect the telescopes.
The squirrels have been forced to live at lower elevations.