An aerial survey of the Bear River Migratory Bird Refuge counted 25,000 swans this past week.
U.S. Fish and Wildlife researcher Vickie Roy said that figure for the graceful waterfowl at the northern Utah site included at least one rare trumpeter swan.All the others were tundra swans, also known as whistling swans.
The Bear River refuge has been a winter stop for up to 60,000 tundra swans in the past, though numbers normally peak around Thanksgiving at some 30,000 birds.
Roy said spotting a trumpeter swan was considered a coup, since 57 of the species were relocated to Bear River late last year.
The relocation project was triggered by overcrowding of the birds at their normal stopover migration habitat near the Idaho, Montana and Wyoming borders.
Roy said the overcrowding was hurting both the survival rate of the birds and causing damage to the environment there because of overgrazing of aquatic vegetation, the swans' main food source.
At one point, near the turn of the century, the known number of trumpeter swans was down to only about 140 birds in the Rocky Mountain area.
While the Red Rocks permanent trumpeter population has grown only by a couple of hundred birds, the migrating trumpeter population is now above 3,000, Roy said.
The goal of the Bear River relocation project was to encourage some of the migrating trumpeters to bypass the tri-state area and come directly to northern Utah on their southern migration.
The project was expected to continue again this year, but politics put an early end to it.
The Trumpeter Swan Sentinel Society protested after nine of the original 20 trumpeters relocated to the refuge were shot by hunters within 48 hours of being turned loose.
Roy said the timing of the release of these birds, each equipped with a radio collar, was part of the research project.
"We wanted to see what percentage of the birds would be shot," she said. She blamed the high rate on the possibility that the released birds were disoriented and were in the air a lot more than the tundras.
The remaining 37 birds were turned loose after the tundra swan hunting season had ended. These birds, however, were not fitted with radio collars, which is why it is so difficult to discover how many of the trumpeters returned to the refuge this season.
Roy said so far, only one known trumpeter swan has been killed by tundra swan hunters.
Complicating relocation efforts was the fact that the trumpeters did not return to the tri-state area in great numbers this past year.
"Possibly, that was because of the hazing tri-state wildlife managers were doing to the birds," Roy said.
The hazing included disturbing the birds with noise, boats, aircraft and anything else that would chase them off, she said.