Trumpeter Swan
A trumpeter swan, North America's largest waterfowl, prepares to land on Flat Creek near Jackson. Photo by Mark Gocke - WGFD
|
|
Trumpeter Swan Survey Results
November 13, 2005
Every September, agency biologists in the Greater Yellowstone (or Tri-State) area conduct a coordinated aerial survey to determine the number and annual productivity of resident Trumpeter Swans in western Wyoming, eastern Idaho and southwestern Montana. Biologists reported overall that swans had a good year in 2005 in the Tri-State area.
In western Wyoming, 18 swan pairs hatched 42 young with 36 (86%) surviving to September. According toSusan Patla, WGFD biologist, "For the first time in Wyoming, swan pairs in the Green River Basin hatched more cygnets (25 vs. 17) and fledged more young (22 vs. 14) compared to the Snake River core area."
Patla attributes this success to WGFD's Green River basin expansion program begun in the early 1990's. In partnership with the local nonprofit group Wyoming Wetland Society, WGFD released a total of 72 cygnets and yearlings in the upper Green River area between 1994 and 2003. Captive swans were raised from salvaged wild eggs or from pairs of the same genetic stock as the resident swans in the Tri-State area.
The goal was to establish 10 nesting pairs outside of the traditional core habitat area near Jackson to expand both summer and winter distribution of this species. Due to high productivity of wild pairs, captive releases were halted in 2004 and work shifted to habitat development. WGFD has shifted its efforts from supplementing swan numbers to developing additional wetland habitat for summering swans in the Green River basin.
Migrating Trumpeter and Tundra Swans from surrounding areas and Canada move into the Jackson area in early November. WGFD requests that area residents report observations of any marked swans or swans in unexpected locations to the department office.
Swans that are being released in Montana and wild swans in Canada might be seen with green, red, or yellow neck collars that are marked with three or four-digit alpha-numeric codes. Swans also may have silver or colored leg bands. Observations should include location, date, color of markers, location of leg bands (left or right leg), and any visible codes. WGFD greatly appreciates help in tracking Trumpeter Swans wherever they may occur in the state.
|
