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")
Bird vocalization and prevent an energetically costly fight . In birds with song repertoires, individuals may share the same song type and use these song types for more complex communication. Some birds will respond to a shared song type with a song-type match (i.e. with the same song type). This may be an aggressive signal, however results are mixed. Birds may also interact using repertoire-matches, wherein a bird responds with a song type that is in its rival's repertoire but is not the song that it is currently singing. This may be a less aggressive act than song-type matching. Communication through bird