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
Arctic Cordillera moss campion, bilberry, and Arctic white heather. The conditions here are far too severe for reptiles and amphibians to survive, and insects are also rare in the region. Muskoxen and barren-ground caribou are the only large herbivores in this environment, while polar bears and the Arctic wolf are the only large carnivores to be found in the region. Smaller herbivores include the Arctic hare and the collared lemming. Arctic foxes and stoats are some of the smaller carnivores found in the region. Marine mammals include narwhals, beluga whales, walrus, and ringed and bearded seals. The furry-legged rock ptarmigan is a