Trumpeter Swans get their name from their loud, sonorous "KO-HOH" call. Today, Trumpeter Swans breed locally in isolated groups in the northwestern US, western Canada, and southern Alaska, but they originally ranged widely across the eastern US as well. Habitat destruction and hunting drastically reduced their numbers almost to the point of extinction by the 1930s. Conservation efforts have allowed the western populations to grow, and they have been successfully reintroduced in suitable habitat in the northcentral US.