Breeding Trumpeter Swans seek relatively shallow (less than 6 feet deep), undisturbed bodies of freshwater with abundant aquatic plants. These heavy-bodied birds also need at least 100 yards of open water for their running take-offs, and muskrat or beaver dens or small islands on which to nest. Breeding sites include small ponds (including beaver and farm ponds), lakes, marshes, bogs, glacial potholes, and quiet stretches of river. As they prepare (or “stage”) for migration, Trumpeter Swans gather at sites near open water, such as inlets with moving water, and larger, deeper lakes. Wintering birds seek out ice-free sites where vegetation is available, including freshwater streams, rivers, springs and reservoirs. In the Pacific Northwest, birds roost and feed in estuaries. In the Midwest, swans may winter on deep ponds of reclaimed surface mines. Wintering swans may forage in croplands and pasture.Back to top
Trumpeter Swans are mainly vegetarians, although they occasionally eat small fish and fish eggs. Younger birds also eat aquatic insects before switching to a plant-dominated diet. Day and night, the birds feed on a broad range of aquatic plants, including pondweeds, eelgrass, marestail, sedges, rushes, duckweed, wild rice and algae. To feed underwater they tip in the air like dabbling ducks, rooting beneath the surface to twist and pull up vegetation or freeing roots by paddling their feet in the mud. In winter they eat a higher percentage of terrestrial plants and berries, such as blueberries, cranberries, lupine, wheatgrass, broom, and ryegrass. Grain crops, including corn and barley, and tubers such as potatoes and carrots also make up part of the wintertime diet. Back to top
Trumpeter Swans build their nests on a site surrounded by water and usually less than 600 feet from shore. The nest is usually built on an existing structure including muskrat and beaver dens, beaver dams, floating vegetation mats, small islands, or manmade platforms. Swan pairs often use the same nest site year after year.
Both sexes collect plant material to build the nest, which includes a foundation topped by a mound of aquatic vegetation, occasionally including grasses and sedges. The female uses her bill and body to shape a nest bowl atop the finished mound. The bowl’s lining may include a few feathers. Nests take 14 - 35 days to build and the completed oblong or circular nest mound can reach up to 11 feet across and 3 feet high, with a bowl measuring 10 - 16 inches across and 4 - 8 inches deep.
|Clutch Size:||4-6 eggs|
|Egg Length:||4.0-5.0 in (10.1-12.6 cm)|
|Egg Width:||2.4-3.2 in (6.2-8.1 cm)|
|Incubation Period:||32-37 days|
|Egg Description:||Creamy to dull white, often stained brown in the nest.|
|Condition at Hatching:||Eyes partially open, covered in mouse-gray or occasionally white down. Leaves nest within 24 hours of hatching and has the ability to swim and feed. Is able to fly at 90 - 122 days after hatching.|
Trumpeter Swans fly with rapid, shallow wingbeats, often traveling in pairs or family groups and flying lower than other swan and duck species. To feed, Trumpeter Swans skim vegetation from the surface, dip their long necks underwater to forage, and tip like dabbling ducks with the rear half of their body in the air as they scour for algae, leaves, stems and roots of pondweeds and other plants. They also pump their large, webbed feet up and down to create water currents that free roots from surrounding mud. Sometimes ducks join feeding swans to glean vegetation and feed on insects they disturb. On land, Trumpeter Swans dig into the soil to find tubers, and nibble or scoop up grain from the ground. The swans spend significant time preening, rubbing their bills in the oil-secreting uropygial gland near the base of the tail, then distributing the oil over the feathers to waterproof them. Swans form long-lasting pairs and may identify a nesting site when less than 2 years old, but often wait several more years to breed. Pairs stay together throughout the year and often migrate and winter in family groups and with other waterfowl, including Tundra Swans, Canada Geese, and Northern Pintails.Back to top
Despite being driven nearly to extinction in the early 20th century, Trumpeter Swans have rebounded and their numbers are increasing. Widespread hunting for meat, skins and feathers from the 1600s - 1800s had reduced this once widespread species to 69 known individuals by 1935, although isolated pockets of the birds also survived in Canada and Alaska. Hunting them is now illegal throughout the U.S. Between 2000 and 2005 a continentwide survey found that Trumpeter Swan numbers had more than tripled, from 11,156 to 34,803. Although Trumpeter Swans have been dubbed “a classic conservation success” and numbers continue to increase, threats such as lead poisoning, habitat loss, power lines, and occasional shooting continue to affect the population. The swans are also extremely sensitive to human disturbance at their breeding sites and will abandon nests and cygnets if disturbed. Ongoing conservation efforts include a set of federal management plans for the three major populations: the Interior, Rocky Mountain, and Pacific Coast birds, along with several state plans. Managers are working to improve breeding and wintering habitat, limit human disturbance, and decrease lead pollution.Back to top
Lutmerding, J. A. and A. S. Love. Longevity records of North American birds. Version 2015.2. Patuxent Wildlife Research Center, Bird Banding Laboratory 2015.
Mitchell, Carl D. and Michael W. Eichholz. (2010). Trumpeter Swan (Cygnus buccinator), version 2.0. In The Birds of North America (P. G. Rodewald, editor). Cornell Lab of Ornithology, Ithaca, New York, USA.
Sibley, D. A. (2014). The Sibley Guide to Birds, second edition. Alfred A. Knopf, New York, USA.