Trumpeter Returns

trumpeterswanHelping Trumpeter swans to relearn their migration patterns can be difficult, as they have a hard time changing the ways that they learn in their first year of life.

 

The problem with trumpeters is that although they live 25 to 30-plus years, they seem to learn everything they ever want to know about migration routes on that first autumn flight from nesting to wintering grounds with their parents. The swans that knew their way to Florida, Texas, or California were shot generations ago, so no cygnet today can pick up that ancestral knowledge naturally. What’s more, the easy life at Red Rock Lakes has favored generations of birds that have lost the drive to migrate at all.

By the early 1980s, Shea and others began to recognize that the crowding was growing perilous. Then, in February 1989, icy winds blasted the temperature down to -40 |degrees~F, and virtually all the open waters in eastern Idaho froze solid.

The ducks and geese simply flew further south, but 500 of the tradition-bound swans sat on the ice at Harriman, unwilling to fly into the unknown. Distressed local residents braved the blizzard to throw grain to the starving birds, but 100 swans died before an emergency release of water from a nearby reservoir melted the water at Henry’s Fork.

News of the disaster prompted the Idaho chapter of the Wildlife Society to petition USFWS to list the swan as a threatened species. Ironically, although the petition was denied, it helped spur the agency to initiate the kind of heroic and costly management effort usually reserved for critically endangered species like the California condor or the black-footed ferret.

“The petition to list got some people’s attention that might not have given it otherwise,” agrees Peck. “For one thing, a listing would have had big impacts in a lot of western states on how water is managed.” To maintain water volume sufficient to keep the streams open for the swans during the winter might require the regular release of reservoir water, a move the agricultural and ranching communities would likely oppose.

“This is the way we ideally should manage any species: recognize when it’s in trouble and take action before it gets to the point where there’s no room for error,” says Peck. He also notes that permits and planning for the current trapping and relocation program would have been enormously more complicated with a listed species.

All that aside, a little charisma never hurts a creature either. “This is a benign, snowy white bird that stands up almost tall enough to look you in the eye,” says Peck. “Swans are hard to hate and hard to ignore. They have the kind of constituency other animals don’t. Lots of things like that have made this a lucky bird.”

At first local residents, who take a proprietary interest in the swans, had grumbled about trapping plans. Then in 1989, the year after the big blizzard, a record number of swans and ducks arrived at Harriman and stripped the river bare.

“That year it looked like the Sahara Desert with water on it,” says Shea. Loss of the aquatic plants to grazing birds threatened the region’s world-class trout fishery, an economic mainstay. Objection to swan dispersal died down.

Over the first two winters, trapping and moving hundreds of swans to balmier wintering grounds has cost USFWS approximately $200,000 per year, Peck estimates, and plans call for at least several more years of effort. So far, he says, the dispersal program is meeting its goals.

“Between 15 and 20% of the translocated birds have returned to the new sites the following fall or winter. |Most of the rest went back to the Harriman area.~ We don’t consider any of these release sites well established yet,” Peck says. But at some sites these marked birds have returned accompanied by their young of the year or by unmarked adults who seem to have tagged along.

“This is particularly encouraging because if we have to rely on getting birds to these sites only in crates, we’re not going to be successful,” he says. The dispersing birds also seem to be using new migration routes west of the Continental Divide as well as the traditional route down the east front of the Rockies to the Yellowstone region.

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