For the last few months, many people have been anxiously following the travels of Pelly, Toobally, Mayo, Dorothy, and Louis. The news was bad -- very bad -- for Louis as he never made it any further than Montana.

But the other four have safely reached their winter home, and even though it is not the location that some might have hoped, at least they now have a known fixed address.

The travelers are trumpeter swans, now wintering in eastern Idaho, close to the western border of Yellowstone National Park. In the summer these birds nest in the Yukon, and last July five of them were caught and fitted with satellite transmitters.

This project marks the very first time that Canadian trumpeter swans have been tracked with satellite telemetry, allowing biologists to figure out their migration routes and winter habitat.

The Canadian swans have been a conservation success story, increasing their numbers in recent years. But their very success breeding in the north is creating problems at the other end of the line on their winter range.

"The dilemma is that even though they are expanding their numbers and their breeding range, they all seem to funnel into this one part of the Yellowstone area for their winter range. That is a very dangerous situation," explains Ruth Shea, the executive director of The Trumpeter Swan Society.

The problem is that the winter range is less than ideal as it is high, cold and small in size. One severe winter could threaten what remains of the roughly 4,400 trumpeter swans that crowd into this area, all part of the Rocky Mountain population of swans.

Most of these birds fly in from Canada just for the winter, but a small group of 400 trumpeter swans lives in the Yellowstone area year-round. Biologists are particularly concerned about this resident group, which is just a remnant of the great flocks of swans that used to splash down in wetlands spread across the lower 48 states.

The trumpeter swans were hunted almost to the edge of extinction, and the knowledge of their traditional migratory patterns was lost with them. Biologists had suspected that most of the Rocky Mountain swans were now wintering in the Yellowstone area, but they had very little hard evidence on the migration before this project went ahead.

The migratory swans in the Rocky Mountain population nest in the Yukon, British Columbia, Alberta and the Northwest Territories. Some trumpeter swans from the Pacific Coast population nest in the southwest Yukon, but more than 95 percent of these birds breed in Alaska. This group of swans also faces threats, but they do spread out more in winter, settling down in wetlands all along the coast from southeast Alaska to Oregon.

The Trumpeter Swan Society teamed up with both the Canadian Wildlife Service (CWS) and the U.S. Fish and Wildlife Service for this project. Most of the funding came from the Wilburforce Foundation and the Yellowstone to Yukon Conservation Initiative, which funds conservation research.

"The fascinating thing was that the theme for the funding was ecological connectivity and the problem with the trumpeter swan is that their migration routes have been severed, so it was a nice match," says Shea.

The society decided to collar birds in the Yukon as CWS biologists here have already done a great deal of work on this species. CWS biologists Jim Hawkings and Nancy Hughes helped put the satellite collars on the five Yukon birds, and fit another ten swans with green coded neckbands to help identify them.

Swans from the Rocky Mountain population nest in a broad arc from the Mayo area to Watson Lake and the southeast Yukon. As the names of the swans indicate, the birds were captured in different parts of their summer range.

"The transmitters are expensive so we tried to scatter them as far apart as we could. We wanted to capture birds with different migratory patterns, and find out whether there is only one winter range or whether some birds might be going elsewhere," says Shea.

Dorothy -- named after the friend of a retired professor who donated money to the project -- was captured southeast of Mayo. Louis, named after the star of E.B. White's classic children's story The Trumpet of the Swan, was captured near Frances Lake and met his demise after flying into a powerline in Montana.

While the biologists were hoping that the collared swans would spread out for the winter, three out of the remaining four are in Harriman State Park in eastern Idaho, which Shea describes as "the center of our problem area." The fourth swan is only about 65 kilometres further south.

In addition to the final destination, the satellite transmitters have also provided other invaluable information. Biologists have learned more on the timing of the migration, and the location of important stopover points along the way, such as Frances Lake in southeastern Yukon.

Wildlife managers are already working to expand the range of the resident swan population. Some swans are captured in the fall and moved to other wintering grounds. Also eggs are taken from nests that would be lost to flooding or drought, and the cygnets are raised in captivity and later released in new habitats further south.

A group of Utah educators has put the migration information on the Shadow A Swan website at www.uen.org/swan. School kids can go online on this site and ask biologists questions about the project. More information is also available on the Trumpeter Swan Society website.