Associated Press - November 12, 2009 2:55 PM ET

CHARLESTON, W.Va. (AP) - Environmental groups have sued a federal agency for removing a flying squirrel found only in high mountain forests of West Virginia and Virginia from the endangered species list.

The groups argue the U.S. Fish and Wildlife Service didn't follow its own protocols when it removed the northern flying squirrel from protected status.

The squirrel subspecies dates back to the Ice Age. It was placed on the list in 1985 after only 10 animals were found.

Wildlife biologists started efforts to delist the flying squirrel after a 2006 study located 1,200 animals in 109 sites.

A Fish and Wildlife Service spokeswoman didn't immediately return a call. The Department of Interior declined to comment on the litigation.

The lawsuit was filed Thursday in federal court in Washington, D.C.

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