Cygnus cygnus, Whooper swans, on a frozen lake in Hokkaido, Hokkaido, Japan

animal behaviour floating condition frozen large group of objects nobody temperature cold point of view side view animal chordate vertebrate bird water bird freshwater bird water frozen water snow standing water lake water surface outdoors season winter day nature beauty in nature wildlife animals in the wild travel place of interest travel destinations swan whooper swan cygnus cygnus whooper swans hokkaido japan