32. Pelecaniformes Herons

The herons are long-legged freshwater and coastal birds in the family Ardeidae, with 64 recognised species (some are called "egrets" or "bitterns" instead of "heron"). Within Ardeidae, all members of the genera Botaurus and Ixobrychus are referred to as "bitterns," and - including the zigzag heron or zigzag bittern - are a monophyletic group within the Ardeidae. However, egrets are not a biologically distinct group from the herons, and tend to be named differently because they are mainly white or have decorative plumes. Although egrets have the same build as herons, they tend to be smaller.

Although herons resemble birds in some other families, such as the storks, ibises, spoonbills and cranes, they differ from these in flying with their necks retracted, not outstretched. They are also one of the bird groups that have powder down. Some members of this group nest colonially in trees, while others, notably the bitterns, use reed beds.