Lessico
Cigno trombettiere
Cygnus buccinator
Trumpeter Swan
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Aves
Order: Anseriformes
Family: Anatidae
Genus: Cygnus
Species: Cygnus buccinator
Binomial name Cygnus buccinator Richardson, 1832
The Trumpeter Swan, Cygnus buccinator, is the largest native North American bird, if measured in terms of weight and length, and is (on average) the largest waterfowl species on earth. Males typically measure from 145–163 cm (57–64 inches) and weigh 11.8 kg (26 lb); females typically range from 139–150 cm (55–60 inches) and weigh 10 kg (22 lb). It is rivaled in size among waterfowl only by the introduced Mute Swan, which is native to Eurasia, but the Trumpeter usually is longer-bodied. Exceptionally large male Trumpeters can reach a length of 183 cm (72 inches), a wingspan of 3 meters (almost 10 ft) and a weight of 17.4 kg (38 lb). The Trumpeter Swan is closely related to the Whooper Swan of Eurasia, and even has been considered the same species by some authorities.
These birds have white plumage with a long neck, a black bill subtly marked with salmon-pink along the mouthline, and short black legs. The cygnets (juveniles) are grey in appearance, becoming white after the first year. The Mute Swan can easily be distinguished by its orange bill and different structure (particularly the neck, which is almost always curved down). The Tundra Swan more closely resembles the Trumpeter, but is quite a bit smaller and usually has yellow lores. Distinguishing Tundra and Trumpeter Swans from a distance (when size is harder to gauge) is quite challenging, and can often be done only with experience and knowledge of structural details. Adults go through a summer moult when they temporarily lose their flight feathers. The females become flightless shortly after the young hatch; the males go through this process about a month later when the females have completed their moult.
Their breeding habitat is large shallow ponds and wide slow rivers in northwestern and central North America, with the largest numbers of breeding pairs found in Alaska. Natural populations of these swans migrate to and from the Pacific coast and portions of the United States, flying in V-shaped flocks. Released populations are mostly non-migratory.
The female lays 3 to 9 eggs in a mound of plant material on a small island, a beaver or muskrat lodge, or a floating platform. The same location may be used for several years. The eggs average 73 mm (2.9 inches) wide, 113.5 mm (4.5 inches) long, and weigh about 320 grams (11.3 oz). The incubation period is 32 to 37 days. These birds often mate for life, and both parents will participate in incubation and brooding. The young are able to swim within two days and usually are capable of feeding themselves after at most two weeks. The fledging stage is reached at 3 to 4 months.
These birds feed while swimming, sometimes up-ending or dabbling to reach submerged food. The diet is almost entirely aquatic plants. In winter, they may also eat grasses and grains in fields. The young are fed on insects and small crustaceans along with plants at first, changing to a vegetation-based diet over the first few months. Predators of Trumpeter Swan eggs include Common Raven (Corvus corax), Common Raccoon (Procyon lotor), Wolverine (Gulo gulo), American Black Bear (Ursus americanus), Brown Bear (Ursus arctos), Coyote (Canis latrans), Gray Wolf (Canis lupus) and Northern River Otter (Lontra canadensis). Most of the same predators will prey on young cygnets, as will Snapping Turtle (Chelhydra serpentina), California Gull (Larus californicus), Great Horned Owl (Bubo virginianus) and American Mink (Mustela vison). Larger cygnets and nesting adults are preyed on by Golden Eagle (Aquila chrysaetos), Bobcat (Lynx rufus), Red Fox (Vulpes vulpes) and Coyote. Few predators, apart from the Bobcat and possibly the Golden Eagle, are capable of taking adults when they are not nesting.
This bird was named for its trumpet-like honk which some compare to the sound of a French horn. The E.B. White novel, The Trumpet of the Swan, is about a Trumpeter Swan which learns to play the trumpet in order to compensate for having been born mute, a reference to another swan, the Mute Swan.
In the 1800s and early 1900s, the Trumpeter Swan was hunted heavily, both as game and a source of feathers. This species is also unusually sensitive to lead poisoning while young. These birds once bred in North America from northwestern Indiana west to Oregon in the U.S., and in Canada from James Bay to the Yukon, but their comparatively small numbers in the southern part of their range were reduced to near zero by the mid-twentieth century. Many thousands survived in the core range in Canada and Alaska, however, where populations have since rebounded. Efforts to reintroduce this bird into other parts of its original range, and to introduce it elsewhere, have had only modest success, as suitable habitats have dwindled and the released birds do not undertake migrations.
www.bsc-eoc.org/avibase/
