Trumpeter Swan |
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North America is home to three species of swans: the native
trumpeter and tundra (formerly known as whistling swan), and the non-native mute. The
trumpeter swan is the largest waterfowl in North America and the largest swan in the
world. The trumpeter swan's historic breeding range extended in a wide band from the Bering Sea east through almost all of Canada and south to Missouri, Illinois, and Indiana. The trumpeter swan is a majestic bird, with snowy white feathers; jet-black bill, feet, and legs; and 8-foot wingspan. At close range, a thin orange-red line can be seen on the lower part of the bill. Trumpeter swan habitat includes riverine wetlands (wetland areas associated with rivers); lakes, ponds, and marshes; open wooded regions; and prairies. In winter, they can be found on tidal estuaries. Trumpeter swans establish life-long mates at approximately 3 years of age and nest the following year. Sometime between late March and early May, they build their nests, choosing locations close to the water, either on shore, small islands, or muskrat and beaver lodges. The male (called a cob) gathers nest material, uprooting marsh plants such as cattails, sedges, bulrushes, and horsetail, and brings them to the female (called a pen) for placement. The nest mound, which takes about 2 weeks to build, reaches a diameter of 6 to 12 feet and an average height of 18 inches. The same nest site may be used for several years. Once the nest is complete, the pen lays one egg every other day until she has a full clutch, usually from 3 to 9 eggs. The pen spends an average of 35 days incubating the eggs while the cob stays nearby to defend the nest against intruders or predators. When they hatch, the downy young (called cygnets) are grayish with pink bills and weigh about 1/2 pound each. Although able to swim immediately, they usually stay in the nest for at least another 24 hours. Newly hatched cygnets feed mainly on aquatic insects and |
crustaceans. At about 5 weeks of age, their diet
changes to include more vegetation. By the age of 2 to 3 months, the cygnets' diet is
basically the same as that of the adults. The tubers of duck potato and sago pondweed are
important foods for trumpeter swans. They also feed on the stems, leaves, and seeds of
other aquatic plants. Trumpeter swans use their strong webbed feet to dig into the pond or lake bottom for
roots, shoots, and tubers, Studies have also shown that trumpeter swans may develop lead poisoning by ingesting lead shot and fishing sinkers during feeding. A relatively recent ban on lead shot for waterfowl hunting has helped significantly decrease this threat in that no new pellets are being deposited in the environment, but old pellets may remain in |
the sediment of lakes and wetlands for several
decades. Under the Migratory Bird Treaty Act, carefully managed hunting of
some migratory birds is allowed under regulations developed each year by the U.S. Fish and
Wildlife Service. The trumpeter swan's close resemblance to the tundra swan and Widespread destruction and degradation of wetland areas also decreases the suitable
habitat areas for the trumpeter swan. Over the years, the Red Rock Lakes refuge flock served as an important source of
breeding birds for reintroduction efforts in other parts of the country, primarily on
other national wildlife refuges in the Midwest. |