Willow ptarmigan by the fact that it is not generally found above the tree line while the rock ptarmigan prefers more elevated, barren habitat. The summer plumage is browner and in the winter, the male willow ptarmigan lacks the rock ptarmigan's black stripe between the eyes and bill. The white-tailed ptarmigan ("Lagopus leucura") in North America is smaller, has a white tail and finely-barred greyer plumage and lives permanently above the tree line. The distinctive British Isles subspecies "L. l. scoticus" (red grouse) was once considered a separate true British species but is now classified as a sub-species. This moorland bird is
USS Ptarmigan (AM-376) USS Ptarmigan (AM-376) USS "Ptarmigan" (AM-376) was an acquired by the United States Navy for the dangerous task of removing mines from minefields laid in the water to prevent ships from passing. She was the only U.S. Navy ship named for the ptarmigan, a grouse with feathered feet, found in northern regions. "Ptarmigan" was laid down 9 March 1944 by Savannah Machine and Foundry Co., Savannah, Georgia; launched 15 July 1944, sponsored by Miss Jeanne Summerlin; and commissioned 15 January 1945, Lt. Alexander B. Barrett in command. "Ptarmigan" departed for the Pacific Ocean 1 May 1945. Following duty off Hawaii