Title: British birds
Year: 1915 (1910s)
Authors: Archibald Thorburn, 1860-1935
Subjects: Birds; Birds
Source book page: https://archive.org/stream/britishbirds03thor/#page/n50/mode/1up
Author Thorburn, Archibald, 1860-1935
Source: https://commons.wikimedia.org/wiki/File:British_birds_(1915)_(20390438476).jpg

The tundra swan (Cygnus columbianus) is a small Holarctic swan. The two taxa within it are usually regarded as conspecific, but are also sometimes split into two species: Bewick's swan (Cygnus bewickii) of the Palaearctic and the whistling swan (Cygnus columbianus) proper of the Nearctic.

The whooper swan (Cygnus cygnus) is a large Northern Hemisphere swan. Whooper swans require large areas of water to live in, especially when they are still growing, because their body weight cannot be supported by their legs for extended periods of time. The whooper swan spends much of its time swimming, straining the water for food, or eating plants that grow on the bottom.

The mute swan (Cygnus olor) is a species of swan and a member of the waterfowl family Anatidae. Cygnus olor is native to much of Eurasia, and (as a rare winter visitor) the far north of Africa. Cygnus olor is an introduced species in North America, Australasia and southern Africa. The name 'mute' derives from it being less vocal than other swan species.