JACKSON - The Wyoming Game and Fish Department will conduct a winter aerial survey for trumpeter swans and other waterfowl in the Pacific Flyway portion of western Wyoming Feb. 4-8. The annual aerial survey is coordinated with the U.S Fish and Wildlife Service to obtain a count of all trumpeters in the Rocky Mountain population in the western United States. The majority of these swans winter in the tri-state area of eastern Idaho, western Wyoming and southwestern Montana with small groups also found in Nevada and Oregon.
Last winter, the survey tallied more than 6,100 trumpeters in the tri-state area, a record high. Over 92 percent (more than 5,000) swans were migrants from interior Canada where nesting populations have shown strong growth for the past few decades. In contrast, only 559 swans (381 adults and 178 cygnets) were counted this past fall in the year-round resident tri-state population, including a total of 207 birds in western Wyoming.
In the last two winter surveys, more than 1,000 trumpeters have been counted in western Wyoming along the Snake, Salt and Green River drainages, five times as many as occur during the summer months. Concentrations occur on open spring creeks along the Snake River south of Grand Teton National Park and on the stretch of open water below Fontenelle Dam on the Green River. On the Salt River, most swans can be found from the “narrows” south to Afton.
Young swans (called cygnets) born this past summer, identified by their light gray-colored feathers, remain with their parents throughout their first winter (an unusual trait among waterfowl). Swans will usually return to the same wintering areas year after year, thus, their numbers build up over time if populations increase.
Because trumpeter swans’ main food source is submerged aquatic plants, they require open areas of calm, shallow water. Given the scarcity of this habitat during Wyoming winters, swans can lose as much as 20 percent of their body weight during extended periods of extreme cold temperatures. Mortality rates can be quite high in severe winters.
Over the next week, Game and Fish biologists request help from the public to find trumpeter swans, especially those located in areas away from main river drainages. “We also want to hear about swans marked with colored neck collars or leg bands,” said Susan Patla, nongame biologist for Game and Fish.
Biologists track the movements of individual birds through alphanumeric codes printed on plastic neck collars and/or leg bands. Recording the swans’ movement by tracking their codes helps determine migration patterns and lifespan.
“If individuals see marked swans, we ask that they please report the color and codes (if visible) along with the location and date of the observation to the local Wyoming Game and Fish office,” said Patla. “It is also important to report any dead swans found throughout the winter.”
Reporting parties can also simply leave a message with their name and contact information at 800-423-4113.
Game and Fish encourages to the public to enjoy swan-watching, but cautions observers not to disturb swans, which could flush them from essential feeding and resting sites. “If swans start to head-bob and vocalize, it is best to draw back before they are forced to fly,” Patla said. Controlling dogs at swan-wintering sites is also important. “If swans lose their sense of security at a particular site, they may not return. Give swans a wide berth, so they can continue to grace our wetlands in both winter and summer.”
(Contact: Al Langston (307) 777-4540)