JACKSON, Wyo. - Members of the Wyoming Wetland Society are incubating trumpeter swan eggs they collected from British Columbia this spring with plans eventually to release the young birds to improve the gene pool of the area population.
This is the second year of a three-year effort to collect Canadian swan eggs. The goal is to increase the number of trumpeter swans that now live in Wyoming, Idaho and Montana as well as to add genetic diversity to the population, now numbering about 500.
Including birds raised in a captive breeding program in Jackson Hole, officials estimate the Wyoming program will have released 350 birds into the three states by the end of this year.
Drew Reed, executive director Wyoming Wetlands Society, said 59 of the 60 swan eggs survived the plane ride to Jackson Hole this year. The society's Trumpeter Swan Fund raised money for the project.
Workers collected eggs from trumpeter swan nests near Fort St. John and Fort Nelson, British Columbia. The program takes only two eggs from each nest, typically leaving four eggs for the nesting birds to rear on their own.
Reed said workers revisited nests this year that had contributed eggs last year and found that about 85 percent were still occupied by nesting pairs n about the same percentage of nests that gets reoccupied in undisturbed areas.
"The sampling indicated that it did not have an effect on the sampled nests," Reed said of collecting the eggs.
The eggs will be incubated at Wyoming Wetland Society co-founder Bill Long's house in Jackson. Once the eggs hatch, the young swans, called cygnets, will be held in breeder pens at Kelly. At another holding facility, seven captive pairs of swans have already hatched 21 cygnets.
Reed said the 59 surviving eggs this year should start hatching in about two weeks. He said the yearlings will be taken to locations that historically had good numbers of nesting pairs, such as the Flathead Indian Reservation in northwest Montana.
The group has released swans in locations like the Blackfoot Valley, where swans have had trouble recolonizing on their own.
"We're working on the fringe of the population to add genetic variation," Reed said. Swans usually migrate back to the places where they learn to fly, so releasing them in such fringe areas can help bird populations in case other habitat areas are threatened.
"This is all designed to create a migratory flock without putting all of your eggs in one basket, so to speak," Long said. "So, if there's a climatic event in one area, it won't potentially wipe out the population."
Long said roughly 5,000 trumpeter swans remain in the Canadian Rockies. But he said that population of birds
typically doesn't form breeding pairs with birds in the U.S., so not much genetic exchange that takes place.