The black-necked crane is an endangered species in the world and is one of the first class protected wildlife in China. Tibet is the world's largest wintering and breeding ground for black-necked cranes. Every year in the middle and late October, a large number of black-necked cranes migrate from northern Tibet plateau to the central and southern river valleys of Tibet for wintering. In March or April the next year, the cranes will fly back to northern Tibet to breed their offspring. In Lhunzhub County, Lhasa, one of the wintering places, groups of black-necked cranes spread their wings in the blue sky to enjoy the warm sun in winter, becoming a beautiful view on the snow-covered plateau.