Sunday, December 7, 2008

Waterfowl Identification: The Swan Trio

There are three species of swans that occur in the United States: Mute, Trumpeter, and Tundra Swans. The Mute Swan was introduced into the United States from Europe. After seeing this graceful beauty you can understand why people would want to have the Mute Swan live close by. The Tundra Swan has the most extensive range but only migrates and winters in the US. The Trumpeter Swan has had a tougher time adapting to habitat loss but in the recent past many reintroduction programs have made a large improvement in the population.

The Trumpeter and Tundra Swans are very similar in appearance while the Mute is easily distinguished from these two. The main difference between the Mute and the other two is that the Mute Swan has an orange bill. Also the Mute Swan usually swims with a more gently “S” curved neck than the other two swan species. At times when the bill is not visible, for example when flying overhead or when sleeping, the identification can be more difficult. In both of these situations look for the long tail of the Mute Swan to differentiate it. In flight the legs will not stick out past the tail tip in the Mute Swan. When on the ground the Mute and Tundra Swans have an uneven rounded back that is humped much closer to the tail than the neck. In the Trumpeter the hump is almost directly in between the neck and tail.

The differences in Trumpeter from Tundra Swans can be very subtle but with the knowledge of a couple key features most can be identified. The Tundra Swan has a spot of yellow on the lores that the Trumpeter does not have. This field mark can be difficult to discern at times depending on the lighting and viewing distance. The bill shape differs as well. The Tundra Swan has a concave upper mandible making the Tundra’s head and bill look much more sloping than the Trumpeter’s.

No matter which swan species you see remember to enjoy it as these birds are as graceful and beautiful as any.

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