This flock of Whooper Swans were congregating on Lake Kussharo in Japan where they typically spend the winter months having migrated from Russia. Whoopers are the largest of all six species of swans throughout the world and are endemic to the European continent. They can weigh as much as 34 pounds and can have a wingspan over nine feet. A close relative of the whooper swan is the Trumpeter Swan that inhabits North America.