In recent winters we have had over 1,000 wintering around American Falls
Reservoir, usually roosting on the reservoir or backwaters of the Snake
River. The majority forage in fields NW of the reservoir and east of the
reservoir on the reservation.

Back in the early 1990s we captured nearly 200 wintering Trumpeters at
Harriman State Park on the Henrys Fork in Island Park and released them in
the Fort Hall bottoms at the north end of the reservoir, as well as other
potential new wintering habitats. Most were migrants from Canadian breeding
grounds. The goal was to disperse wintering swans from high risk winter
habitat in Island Park following termination of winter feeding at Red Rock
Lakes NWR and create a new wintering area at Fort Hall.

Our hope was to rebuild southward migratory traditions and encourage the
swans to explore southern Idaho and hopefully follow the historic route
through Utah and Nevada to milder wintering areas. Fort Hall was one of
our most successful new wintering sites.

If you view the species map on e-bird you can see how their winter range
has expanded as we had hoped. Hundreds can also be found in the Bear River
drainage of Idaho and Utah. Over the past 20 years the swans have made a
major ecological shift to winter field feeding which has greatly aided
their successful expansion in southern Idaho and westward along the Snake
River corridor. Expanded winter food resources have enabled the Canadian
nesting Trumpeters to repopulate many areas where they had been extirpated
by 1900 and increase strongly in the last 25 years.