The Bewick’s Swan is a sub-species of the native Tundra Swan seen in North America. The Bewick’s swan is much smaller and has a shorter and straighter neck than the whooper and mute swan. The yellow shape on its beak is like a blob of butter, while a whooper swan’s seems like a wedge of cheese.
Here is Bewick’s Swan on abstract water ripples at Swan Lake Iris Gardens, Sumter, SC
