Trumpeter swan was still capable of flight due to its bulk. The adult trumpeter swan is all white in plumage. Like mute swan cygnets, the cygnets of the trumpeter swan have light grey plumage and pinkish legs, and gain their white plumage after about a year. As with a whooper swan, this species has upright posture and generally swims with a straight neck. The trumpeter swan has a large, wedge-shaped black bill that can, in some cases, be minimally lined with salmon-pink coloration around the mouth. The bill, measuring , is up to twice the length of a Canada goose's ("Branta canadensis")
Dark-winged trumpeter species: "P. viridis" between the Madeira and Tapajós rivers, "P. dextralis" between the Tapajós and Tocantins rivers, and "P. obscura" east of the Tocantins. The taxon "dextralis" can potentially be split further, with "interjecta" between Tocantins and Xingu, and "true" "dextralis" for the population between the Tapajós and Xingu. Dark-winged trumpeter The dark-winged trumpeter ("Psophia viridis") is a species of bird in the family Psophiidae. It is found in the Amazon rainforest of Brazil, but only south of the Amazon River and east of the Madeira River. The eastern range of dark-winged trumpeter extends into the lower adjacent Tocantins River