Rocky Mountain Population

Photograph by A. Frederickson


  • Rocky Mountain Population (RMP) refers to several geographically disjunct breeding groups that are linked more or less to the Rocky Mountains.
  • In the 2010 rangewide survey the RMP reached a record high of 9,626 including 6,316 adults and 3,310 cygnets. The Canadian Flocks totaled 8,950, the Tri-state Area Flocks 487, and the Restoration Flocks 189. Annual growth rate of the RMP from 1968 to 2010 was 6.3% and from 2005 to 2010 was 84%.
  • The RMP/Canadian Flocks include Trumpeters nesting in central and eastern Yukon, Northwest Territory, northeastern British Columbia, Alberta, and likely now extirpated from southwest Saskatchewan).
  • The much smaller RMP/U.S. Breeding Segment includes the Tri-state Area Flocks that nest in the Greater Yellowstone region of Montana, Wyoming, and Idaho, and the Restoration Flocks in the Malheur NWR vicinity of Oregon, the Ruby Lakes NWR vicinity of Nevada, the Flathead Valley of Montana, and the Blackfoot Valley of Montana.
  • The Tri-state Area Flocks are the only nesting group ofTrumpeters in the lower 48 states that was not eliminated by the early 1900s as the species neared extinction.
  • With less than 70 nesting pairs in the entire RMP/U.S. segment, Trumpeter Swans are one of the rarest native breeding bird species in the western US; during the past 5 years there has been an average of 56 nesting pairs in Greater Yellowstone.
  • The 2008 Pacific Flyway Management Plan for the Rocky Mountain Trumpeter Swan Populations sets a minimum goal of 540 adults and 117 nesting pairs for Greater Yellowstone Trumpeter Swans by 2013.
  • The entire RMP was petitioned for listing under the Endangered Species Act in 1989 and the Greater Yellowstone population was petitioned for listing as a distinct population segment (DPS) in 2001. Both petitions were denied by the US Fish and Wildlife Service. Though TTSS has great concern for the security of both the Western Canadian and Greater Yellowstone populations, we concurred with both decisions because we did not believe that listing would have been legally appropriate or beneficial for the swans.
  • Most swans from the Western Canada and Greater Yellowstone populations winter together in the Greater Yellowstone region, where over 5,700 swans were censused in February 2011.


  • Greater Yellowstone's nesting Trumpeters are not secure due to their low numbers, low productivity, diminished breeding and wintering range, and increasing human activity and habitat decline in historic nesting areas.
  • The future security of Greater Yellowstone's breeding population will depend in large part on improving nesting success at the region's largest and best breeding habitat at Red Rock Lakes National Wildlife Refuge, and on other federal and state refuges in the region
  • The decline of the Red Rock Lakes National Wildlife Refuge flock following termination of artificial feeding in 1992 and further decline in nesting on the refuge since 2001.
  • The restoration flocks in Oregon and Nevada are extremely small and will likely become extirpated without concerted efforts to build up these groups in the next few years.
  • Increasing concentration of almost the entire Western Canadian and Greater Yellowstone breeding populations at wintering sites in the Greater Yellowstone region due to the elimination of migrations to other diverse wintering areas.
  • High probability of a large die-off of Western Canadian and Greater Yellowstone Trumpeters when a severe winter strikes the Greater Yellowstone wintering areas and freezes essential feeding areas.
  • Mortality of Trumpeter Swans that attempt to migrate south from Greater Yellowstone and the loss of opportunities for Trumpeters to establish use on key National Wildlife Refuges in Utah and Nevada due to Tundra Swan hunting.

TTSS' Efforts

  • Work with our partners to achieve the Pacific Flyway Management Plan goals for U.S. flocks.
  • Continue to work with our Oregon Trumpeter Swan Restoration Project partners to achieve the target objectives of 75 adults and 15 nesting pairs.
  • Continue to work with Red Rock Lakes NWR, Montana on swan management plans and habitat conditions.
  • Continue to encourage our partners to monitor nesting territories to increase nest success, cygnet production, and connectivity between flocks.
  • Continue to work with partners in the Greater Yellowstone region and other areas of the Rocky Mountain Population to identify trends and population/habitat relationships.
  • Continue to work with partners and a network of on-the-ground wetland managers to coordinate regional restoration efforts and share information and data.
  • Work with partners to monitor the distribution and movements of Greater Yellowstone and other Rocky Mountain Population swans.
  • Work with partners with a network of private wetland owners whose lands could provide significant breeding or foraging habitat for Trumpeters.
  • Review and comment on all proposed developments and management actions that would impact important habitats or population security.
  • Provide technical assistance to state/provincial and federal range expansion efforts.
  • Work to raise public awareness regarding the vulnerability of the Greater Yellowstone population and the Rocky Mountain Population and the need for increased restoration and connectivity efforts.


  • Alerted the public and US Fish and Wildlife Service to very serious deficiencies in the 2008 draft managment plan for Red Rock Lakes NWR.
  • Conducted the first-ever satellite telemetry of Western Canadian Trumpeters with our Trumpeter Swan Migration Project and documented their migration routes to Greater Yellowstone.
  • Identified and implemented projects to improve historic nesting territories on the Caribou-Targhee National Forest in eastern Idaho.
  • Developed site plans for the long-term protection and management of nesting territories on the Caribou-Targhee National Forest.
  • Coordinated nest monitoring on all Idaho nesting pairs since 1995.
  • Developed site plans for the long-term protection and management of nesting territories on the Caribou-Targhee National Forest.
  • Launched a project in Montana's Centennial Valley to document all past swan nesting use of wetlands and improve habitat conditions on wetlands with mixed public/private ownership.
  • Played a lead role in assembling data and developing strategies for all past management documents for RMP Trumpeters, including the most recent (2008) Pacific Flyway Management Plan for Rocky Mountain Trumpeter Swans.
  • Obtained genetic samples from over 50 Yukon, British Columbia, and Idaho breeding Trumpeter Swans to aid ongoing genetic research.