Willow ptarmigan complicated changes in plumage several times a year and the differing colour and pattern of the summer plumage: The willow ptarmigan often hybridises with the black grouse ("Tetrao tetrix") and the hazel grouse ("Tetrastes bonasia") and occasionally with the western capercaillie ("Tetrao urogallus"), the spruce grouse ("Falcipennis canadensis") and the rock ptarmigan ("Lagopus muta"). During the Pleistocene, the willow ptarmigan widely occurred in continental Europe. Authors who recognize paleosubspecies have named the Pleistocene willow ptarmigan "L. l. noaillensis" (though the older name "medius" might be the correct one). These marginally different birds are said to have gradually changed from the
Chionophile Chionophile Chionophiles are any organisms (animals, plants, fungi, etc.) that can thrive in cold winter conditions (the word is derived from the Greek word "chion" meaning "snow", and "-phile" meaning "lover"). These animals have specialized adaptations that help them survive the harshest winters. Animals such as caribou, Arctic hares, Arctic ground squirrels, snowy owls, puffins, tundra swan, snow geese, Steller's eiders and willow ptarmigan all survive the harsh Arctic winters quite easily and some, like the willow ptarmigan, are only found in the Arctic region. Antarctica, also known as the southern pole, is larger and can become much colder than