Trumpeter, whooper and black-necked are all varieties of what?
Trumpeter, whooper and black-necked are varieties of swan. Swans are birds of the family 'Anatidae' within the genus 'Cygnus'. The swans' closest relatives include geese and ducks.
Swans are the largest extant members of the waterfowl family, and are among the largest flying birds. The largest species, including the mute swan, trumpeter swan, and whooper swan, can reach a length of over 1.5 m (59 in) and weigh over 15 kg (33 lb). Their wingspans can be over 3.1 m (10 ft). Compared to the closely related geese, they are much larger and have proportionally larger feet and necks. Quite unusual for birds, swans have "teeth" - jagged parts of their bill that are used for catching and eating fish. Adults also have a patch of unfeathered skin between the eyes and bill. The sexes are alike in plumage, but males are generally bigger and heavier than females.
The Northern Hemisphere species of swan have pure white plumage but the Southern Hemisphere species are mixed black and white. The Australian black swan (Cygnus atratus) is completely black except for the white flight feathers on its wings; the chicks of black swans are light grey. The South American black-necked swan has a white body with a black neck.