The mute swan (Cygnus olor) belongs to the Anatidae family. Those birds of medium to large size, occupied all continents except Antarctica. The family counts 165 species. They are closely linked to water, mainly to fresh water. Their short legs are webbed and their general color snow-white with an orange-red beak. A characteristic black tuber stands at the beginning of the beak. The sexes are identical, except in spring: the tuber becomes larger in the male than in the female. They float smoothly on Lake Madine.