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[Trumpeter Swan in Yellowstone National Park - Photo by Wayne Arnall]
The Rocky Mountain Population (RMP) of trumpeter swans (Cygnus buccinator) has been identified by the U.S. Fish and Wildlife Service's Focal Species strategy as a group of management concern. The harvest of these birds during the 1800s, primarily for their skins, along with habitat alterations in nesting and wintering areas, reduced the range and abundance of this population. By the early 1900s, only about 30 birds were known to exist in the U.S. The RMP is comprised primarily of two nesting flocks that are separated geographically, but that are not genetically different. The Canadian group nests primarily in western Alberta, northeastern British Columbia, and the southern Yukon Territory and Northwest Territories, and is comprised of about 4,500 birds. The U.S. nesting flocks nest primarily in the Greater Yellowstone areas of Montana, Idaho, and Wyoming, commonly referred to as the Tri-state Area. These birds are much less abundant, consisting of only about 500 birds. Birds from both of these nesting areas winter sympatrically in the Greater Yellowstone area of the U.S. Intensive management efforts, including cessation of trumpeter swan hunting in the early 1900s, habitat manipulations, and translocation and reintroduction of birds to areas within their historic range have been undertaken and the status of this population has dramatically improved from its historic lows. Although the number of RMP swans is increasing, managers remain concerned about the ability of winter habitat to meet the needs of this growing population.
Date: October 2008
Source: Subcommittee on Rocky Mountain Trumpeter Swans. 2008. Pacific Flyway management plan for the Rocky Mountain Population of Trumpeter Swans. Pacific Flyway Study Committee, c/o U.S. Fish and Wildlife Service Division of Migratory Bird Management, Pacific Flyway Representative, Portland, Oregon.
Species Profile from NatureServe
Trumpeter Swan Cygnus buccinator
Description:A large swan native to North America.
Life History:Nesting begins in late April or early May in the intermountain western U.S. Clutch size is 2-9 (usually about 5). Incubation, mainly by female, lasts 33-37 days (Harrison 1978). Hatching occurs in latter half of June in southern Alaska, June in the intermountain Western U.S. Nestlings are precocial but remain with adults until subsequent spring. Fledging occurs at 100-120 days. Young remain with parents through winter; siblings may stay together for a few years, may rejoin parents after the nesting period. First nests at 4-5 years (may form pair bonds earlier). Life-long pair bond. Rarely more than one pair nests on a single body of water.
Habitat:Ponds, lakes, and marshes, breeding in areas of reeds, sedges or similar emergent vegetation, primarily on freshwater, occasionally in brackish situations, wintering on open ponds, lakes and sheltered bays and estuaries (AOU 1983). In the intermountain western U.S., winters in areas of geothermal activity, springs, and dam outflows (Spahr et al. 1991). Primarily breeds in freshwater, on edges of large inland waters; typically in emergent marsh vegetation, or on a muskrat house, beaver lodge, or island. The nest is a large mass of plant material. Uses same nesting sites in successive years.
See Pacific Flyway Study Committe (2004) for a summary of nesting, migration, and winter habitat requirements for the Rocky Mountain population.
United States: AK, AR, AZ, CO, IA, ID, IL (extirpated), KS, KY (extirpated), LA (extirpated), MD (extirpated), MI, MN, MO (extirpated), MT, ND (extirpated), NE, NV, OK, OR, SD, UT, VA (extirpated), WA, WI, WY
Canada: AB, BC, MB, NT, ON, SK, YT
Status:
NatureServe Status: Global Status: G4, Global Status Last Reviewed: 31Jan2005, Global Status Last Changed: 20Nov1996, Rounded Global Status: G4 - Apparently Secure
Other Statuses: Committee on the Status of Endangered Wildlife in Canada (COSEWIC): Not at Risk (01Apr1996), IUCN Red List Category: LC - Least concern
