nicnaturalist's Identifications

Scientific and Common Name
Cygnus buccinator or commonly known as the Trumpeter Swan (Squires & Anderson, 1997).
Habitat and Geographic Range
The habitat of the Trumpeter Swan can be broken down into three different sites: breeding, wintering and migration stopover. The breeding location is usually in ponds, lakes, marshes, and rivers (Mitchell & Eichholz, 2010). Key features would be room for takeoff, beaver/muskrat dens for nesting sites, food abundance, and low human presence (Mitchell & Eichholz, 2010). The wintering location can include any of the breeding locations without the presence of ice or estuaries, since brackish waters cannot freeze (Mitchell & Eichholz, 2010). The stopover locations are ice free and resource abundant, which allow the swan to replenish lost resources in migration (LaMontagne et al., 2003). Populations of Trumpeter Swans can be seen throughout North America. There are three populations that are currently recognized: the Pacific Coast, the Rocky Mountain, and Interior population (Dewhurst, 2012). The Pacific Coast population is found in Alaska and Northern Canada and migrate to southern British Columbia and Northwestern United States (specifically Washington and Oregon) (Mitchell & Eichholz, 2010). The Rocky Mountain population encompasses a number of breeding groups that are within the rocky mountain range (Banko, 1960). There are the Alaskan and N. Canada groups that migrate into the tristate area (the border of Wyoming, Idaho, and Montana) and local populations in this region that will move to nearby ice-free areas (Mitchell & Eichholz, 2010). The Interior population is located in the North Central United States and Central/Eastern Canada. They have also been found as far south as California (Mitchell & Eichholz, 2010).
Size/Weight and Life Span
There is variation between sexes and geographic regions. Males tend to have a weight of 12.5 kg in Yellowstone Park (Banko, 1960), 11.8 kg in Alaska, and 11.4 kg in the Red Rock Lakes (Barrett & Vyse, 1982). The average wingspan was around 96.5 inches and a total length of 48-62 inches from bill to tail (Banko, 1960). The females are smaller in comparison to males. They had a weight at 10.2 kg in Alaska and 10.3 in Red Rock Lakes (Barrett & Vyse, 1982). Their average wingspan was 74 inches and average total length was 54 inches (Banko, 1960). The average life span of the Trumpeter Swan is around 23.8 years (Krementz et al., 1989). Captive Swans have been found to live to a maximum age of 32.5 and wild individuals have been documented at over 24.5 years of age (Mitchell & Eichholz, 2010).
Diet
Trumpeters Swans are primarily herbivores. Their diet consists mainly of aquatic plants and favor the roots, leaves, and the tubers (Banko, 1960). Their diet varies based on the season, as they seem to prefer pond weed in the summer as it was accounted for 48.2% of food intake (Squires & Anderson, 1997). In the winter and spring Sago Pondweed tubers accounts for 23.5% and 38.5% respectively (Squires & Anderson, 1997). The Trumpeter cygnets have a slightly different diet in comparison to adults since they are too small to reach down into the waterbed to retrieve the aquatic plants (Banko, 1960). Their diet consists of invertebrates and any plant residue that the adults release from the bottom, till about 5 weeks of age (Banko, 1960).
Reproduction and Communication
Trumpeter Swans are monogamous and will form pairs at around three years of age (with mating occurring during the 4th year) (Banko, 1960). While they can mate for life some swans can be have successive monogamous relationships or if a mate dies the widow may take a new mate (Banko, 1960). They form their nests in old beaver or muskrat dens (Banko, 1960). Typically the Swans will lay on average 4 to 6 eggs at 39 to 48 hour intervals in a single breeding season (Mitchell & Eichholz, 2010). The Trumpeter Swan is an expressive animal and will use its trumpet-like call, which inspired their name, to communicate with other individuals (Banko, 1960). They may also use head and neck movements to communicate danger with other members in a group (Mitchell & Eichholz, 2010). Breeding swans tend to be less vocal than those that are not (Banko, 1960). Hissing and feet stomping has also been documented as a sign of aggression or in cases when the bird feels threatened (Banko, 1960).
Predation
Predation can be seen at the different developmental stages of the swan. The eggs may be preyed on by smaller vertebrates, such as racoons and otters, or bears and wolves (Mitchell & Eichholz, 2010). Cygnets are susceptible to similar species that prey on eggs but also can be targeted by Northern Pike and other birds, such as ravens or bald eagles (Mitchell & Eichholz, 2010). The golden eagle has been documented as a predator of adult trumpeters but little support for other any others (Sharp, 1951).
Conservation Status
The conservation status of Cygnus buccinator is categorized as least concern, meaning they are the furthest from extinction (The IUCN Red List of Threatened Species, 2016). Numbers in the wild have been reported at 34,803 in 2005 and are increasing (Mitchell & Eichholz, 2010).
Did you know? The Trumpeter Swan is the largest flying bird. Due to its extraordinary weight they need around a hundred metres of space to take off. They actually gallop across the water as they take off and you can hear their feet slapping the surface (Banko, 1960).
References
Barrett, V. A., & Vyse, E. R. (1982). Comparative Genetics of Three Trumpeter Swan Populations. The Auk, 99(1), 103–108.
Banko, W. E. (1960). The TRUMPETER SWAN ITS HISTORY, HABITS, AND POPULATION IN THE UNITED STATES. North American Fauna, 1-214.
Dewhurst, D. (2012). The 2010 North American Trumpeter Swan Survey.
Krementz, D. G., Sauer, J. R., & Nichols, J. D. (1989). Model-Based Estimates of Annual Survival Rate Are Preferable to Observed Maximum Lifespan Statistics for Use in Comparative Life-History Studies. Oikos, 56(2), 203–208.
LaMontagne, J. M., Jackson, L. J., & Barclay, R. M. . (2003). Characteristics of ponds used by trumpeter swans in a spring migration stopover area. Canadian Journal of Zoology, 81(11), 1791–1798.
Mitchell, C. D. & Eichholz, M. W. .(2010). Trumpeter Swan (Cygnus buccinator). The Birds of North America Online. https://doi.org/10.2173/bna.105
Sharp, W. M. (1951). Observations on predator-prey relations between wild ducks, trumpeter swans and golden eagles. The Journal of Wildlife Management, 15(2), 224-226.
Squires, J. R., & Anderson, S. H. (1995). Trumpeter swan (Cygnus buccinator) food habits in the Greater Yellowstone Ecosystem. American Midland Naturalist, 274-282.
The IUCN Red List of Threatened Species. (2016). Retrieved October 22, 2016, from http://www.iucnredlist.org/