Mute Swan

The Mute Swan is one of a handful of breeding birds in New Hampshire that is not native to North America. Native to Europe and temperate parts of Asia, they have long been a common “ornamental” bird in parks and aviaries and were brought to the United States for these same purposes starting in the 1800s. As one might expect, some escaped, and naturalized populations now occur along the east coast, around the Great Lakes, and in the Pacific Northwest.

It should also come as no surprise that as a non-native species, Mute Swans can cause problems where they have become established. Because they are highly territorial, they may aggressively exclude other waterfowl from nesting areas, sometimes even killing them. They can also overgraze native vegetation, and there is even a case of swans trampling Least Tern chicks on islands in Chesapeake Bay. For these reasons they are increasingly subject to control measures that include egg-addling (shaking eggs to render them unviable), culling, or translocation. The former strategy was implemented around Great Bay in the early 2000s, resulting in the near loss of swans as a breeding species in that area. Now most of the New Hampshire population is found at scattered wetlands in the southern part of the state, with occasional wandering birds as far north as the Lakes Region.

Two native swan species occur irregularly in New Hampshire. The Tundra Swan is a rare migrant, primarily along the Connecticut River, in early spring and late fall. The best way to tell it from a Mute Swan is posture: Tundra Swan tend to hold its neck straight with the bill horizonal, vs. an s-shaped neck with downward pointing bill in the Mute. In 2019, a lone Trumpeter Swan spent several months at a wetland in Candia, the only record of this historically western species for the state. This bird probably came from a growing reintroduced population in the Great Lakes, and it’s likely that more Trumpeters will be reported in the future.