The trumpeter swan (Cygnus buccinator), named for its resonant call, is North America’s largest wild waterfowl, with a wingspan of up to eight feet. These swans require open water, feed mainly on aquatic plants, and nest in wetlands. Although they once nested from Alaska to northern Missouri, trumpeter swans were nearly extirpated in the lower 48 states by 1930 due to habitat loss and hunting. Small populations survived in isolated areas such as the Greater Yellowstone Ecosystem, where the population was thought to number only 69.
As a result of conservation measures, populations across the continental United States began increasing. Today there are approximately 46,000 trumpeter swans in North America. Swans in the Greater Yellowstone Ecosystem played a significant role in the population resurgence, but by the early 1960s, cygnet production in Yellowstone and subsequent recruitment of adults into the breeding population began declining. Continue: Population and Outlook
Number in Yellowstone
23 resident swans in 2015, including releases and young of the year.
Trumpeter swans are increasing in the Rocky Mountains, stable in the Greater Yellowstone Ecosystem, but declining in Yellowstone National Park.