Trumpeter swan which is apparent even when the swan is not standing or swimming upright) and larger, wedge-shaped bill as compared to the tundra swan. Trumpeter swans have similar calls to whooper swans and Bewick's swans. They are loud and somewhat musical creatures, with their cry sounding similar to a trumpet, which gave the bird its name. Beginning in 1968, repeated in 1975, and then conducted at 5-year intervals, a cooperative pan-continental survey of trumpeter swans was last conducted in 2015. The survey assesses trumpeter swan abundance and productivity throughout the entire breeding ranges of the three recognized North American populations: the
Dark-winged trumpeter 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 drainage in the Brazilian state of Pará. As of 2012, this species is listed as Endangered, with the easternmost subspecies "obscura" rare. There are some differences in the colour of the back and chest in the subspecies, and it has been suggested that these should be treated as separate