Trumpeter Swan – Cygnus buccinators (Richardson, 1832)
Appearance: The Trumpeter Swan is the largest of all swan species, growing up to 1800mm long. Adults have white plumage with a characteristically long heavy bill that is completely black. It is a long-necked bird, with short black legs set well back on body. It is commonly confused in the field with the smaller Whistling Swan (C. columbianus), but is distinguished by its greater size, and black bill with no traces of yellow near the eye. Whistling Swans also have a more rounded head in profile, and a comparatively slender bill.
Cygnets are pale grey in colour, with darker areas on the rump, shoulder and nape of neck. The bill is mainly pink from hatching, becoming greyish pink at the base and edge of the bill. Legs are feet range from orange to pinkish grey to black during the first year (Nelson, 1976b, 1993).
Voice: Trumpeters have a very deep call from which its name is derived. Vocalizations vary with social context, loud open-mouthed calls associated with
aggressive encounters and Triumph display, whereas softer, more nasal contact calls used to maintain family cohesion. Young birds make high pitched calls, developing their more basal tones at 6-8 months (Banko, 1960).
Moult: Adult Trumpeters wing moult occurs during June-September for 30-40 days each year. Paired birds tend to moult asynchronously (Mitchell, 1994).
Distribution: Historically widespread, breeding over wide area from central Alaska across Canada to Newfoundland, and south to Carolinas in eastern US, and to Idaho, Oregon, and perhaps California in the west. The wintering range equally extensive, ranging from southern Alaska to southern California, central Florida and Gulf of Mexico.
Pacific Coast population: This population breeds in Alaska and winters from Southern Alaska down to Washington State.
Rocky Mountain population: This population breeds in parts of Canada and Northern USA.
Interior population: This population consist of restored flocks in North-central USA.
|Population||Year of latest pop. estimate||Population size||Data types||Trend years||Trend||Trend quality||1% threshold||Source|
|Pacific coast||2010||26,700-26,800||Expert opinion||2005-2010||INC||UNK||270||(1)|
|Rocky Mountain||2010||9,620-9,630||Expert opinion||2005-2010||INC||UNK||95||(1)|
From: Wetlands International (2016). (1) Trumpeter Swan Society (2012).
Habitat: Uses a wide range of habitats in both summer and winter, but nests mainly in fresh water marshes with abundant invertebrates and aquatic vegetation (Lockman et al. 1987, Squires 1991, Mitchell 1994). Breeds mainly in or surrounded by water, and nesting density can be variable. The Trumpeter will use larger marshes and lakes during migration, preferring ice-free areas where feeding is possible (Gale et al. 1987). Habitat in winter is very much dependant on this need to find available ice-free water areas.
Protection: Passage of the Migratory Bird Treaty Act of 1918 helped curb illegal killing (Robert Savannah).
IUCN Red List Assessment: Least Concern (LC)
Current population trend: Increasing
Threats: Used in Jewellery and handicrafts. Taken for pets and animal displays. Climate change and severe weather Habitat shifting & alteration (BirdLife International, 2012).
Banko,W.E. (1960). The Trumpeter Swan. Its history, habits, and population in the United States, N.American Fauna, No. 63. US Fish & Wildl. Serv.,Washington.
BirdLife International (2012). Cygnus buccinator. The IUCN Red List of Threatened Species 2012. Available from: http://www.iucnredlist.org/details/full/22679859/0#end_uses [Accessed 7 March 2016].
del Hoyo, J., Collar, N.J., Christie, D.A., Elliott, A. and Fishpool, L.D.C. (2014) HBW and BirdLife International Illustrated Checklist of the Birds of the World. Lynx Edicions and BirdLife International.
Gale, R.S., Garton, E.O. and Ball, I.J. (1987). The history, ecology, and management of the Rocky Mountain population of Trumpeter Swans. US Fish & Wildl. Service, Montana Cooperative Wildl. Research Unit, Missoula.
Kear, J. (2005) Ducks, geese and swans volume 1: general chapters; species accounts (Anhima to Salvadorina). Oxford University Press, Oxford, U.K.
Lockman, D.C.,Wood, R., Burgess, H., Burgess, R. and Smith, H. (1987). Rocky Mountain Trumpeter Swan population.Wyoming flock. 1982–1986.Wyoming Game and Fish Dept., Cheyenne.
Mitchell, C.D. (1994). Trumpeter Swan (Cygnus buccinator). The Birds of North America, No. 105 (ed. A. Poole and F. Gill).AOU,Washington, and Academy of Natural Sciences, Philadelphia.
Nelson, C.H. (1976) A key to downy cygnets with analysis of plumage characters. Wilson Bull. 88: 4–15.
Robert Savannah (no date). Trumpeter swan (Olor buccinators). Available from: http://www.fws.gov/species/species_accounts/bio_swan.html. Accessed 7 March 2016].
Squires, J.R. (1991). Trumpeter Swan food habits, forage processing, activities and habitat use. Unpubl. Ph.D. thesis. Univ.Wyoming, Laramie, US.
Trumpeter Swan Society (2012) Available from: www.trumpeterswansociety.org. [Accessed: April 2012].
Wetlands International (2016) Waterbird Population Estimates. Available from: wpe.wetlands.org [Accessed Friday 5 Feb 2016].