"Who has ever paddled a canoe, or cast a fly, or pitched a tent in the north woods and has not stopped to listen to this wail of the wilderness? And what would the wilderness be without it?"
- Arthur Cleveland Bent, naturalist
For Canadians, the familiar cry of the loon rolling eerily out across the still surface of a lake at twilight is a reminder of who they are, a cherished symbol of wilderness ingrained in the national psyche.
But what if Canadians camping at water's edge listened and there was no loon to send out its hauntingly beautiful call?
Now comes word Canada's beloved unofficial bird, whose picture is inscribed on every dollar coin (called a "loonie"), may be in growing danger of falling victim to mercury poisoning, according to a new study.
"The loon is the Canadian equivalent of the Bald Eagle to Americans," says Neil Burgess, a Canadian government biologist who has discovered high levels of mercury in loons in Canada's Maritime Provinces (Nova Scotia, New Brunswick, Prince Edward Island). "Most Canadians have memories early in childhood of hearing a loon. There's a strong emotional connection."
So strong is the tie that since 1981 thousands of Canadian volunteers have helped track populations of the 4 out of 5 species of loon that nest in Canada. By some estimates, the Canadian population of the common loon - by far the largest in number - is between 250,000 and 500,000.
Canada's top loon counter is Harry Vogel, a biologist who heads the Canadian Lakes Loon Survey, a nonprofit group based in Port Rowan, Ont., that orchestrates an annual nationwide loon population survey using volunteers. Participation in the survey is growing by leaps and bounds with 1,100 participants last year, up 40 percent from 1995.
While the Common Loon, a water bird with a striking black-and-white checkered back, white belly, black head, and white necklace around its throat is found across Canada, the Great Lakes, Alaska, and New England, concerns about declining populations and breeding problems have been growing for a decade - especially in Canada.
Mr. Burgess and researchers in the United States say they have found high levels of mercury in the blood and feathers of the birds of North America - particularly in the Maritime Provinces and New England. The levels rise from west to east. Birds from Alaska had much less mercury compared with loons tested in Nova Scotia and New England.
Canada's Maritime Provinces are the "tailpipe" of North America, Burgess says. He and others believe mercury released in the air by smokestacks of incinerators and power plants in the US and southern Canada is wafting eastward to be deposited onto lake watersheds and into the food chain.
Joe Kaplan, a biologist with BioDiversity Inc., a private company based in Freeport, Maine, says the Canadian data shows the loons in the Maritimes have by far the highest level of mercury compared with other regions. While loons seem abundant, poor breeding trends in the Canadian Maritimes - about half of normal - do not appear good.
"What we want to know is how much of this mercury is natural [leaching into the water from surrounding rock], and how much is a result of fossil-fuel burning and other human causes," Mr. Kaplan says.
Elusive and apt to dive under water when approached, loons are difficult subject for researchers. They only began studying loons seriously in 1989 when David Evers, a US biologist, discovered how to catch them. He carried a tape recorder with loon cries out onto a lake at night and curious loons came close enough for him to net them.
A large loon can weigh up to 13 pounds and live 15 to 30 years. It is streamlined, with legs placed far back on its body. This makes the loon a good swimmer, but ungainly on land. Loons migrate during winter from inland lakes that freeze over to the East and West coast and the Gulf of Mexico. To take off, the loon must run across the water into the wind to get enough momentum
Whatever it is about the bird, there can be no question that Canadians are crazy about the loon, spending substantial sums for loon recordings, posters, calendars, and other loon paraphernalia readily available in gift and card shops across the country.
Still, Vogel of the Canadian Lake Loon Survey notes that his organization is finding it increasingly difficult to fund its research. He finds it ironic that, in a country where loon appeal is big business, it is hard to get companies to help sponsor the survey.
"More often than not, they're not interested in doing anything but using the image and sounds of the loon to sell a product," Vogel says, "which I think is a little bit despicable."