Newswise — Loons, whose haunting calls are a hallmark of the northwoods, may be at serious risk from an activity beloved by many wilderness visitors.

"Loons are not fans of canoes," says Joseph Kaplan, who is completing his master's degree in forestry at Michigan Technological University. "We are finding that recreation, especially canoeing, on Isle Royale's inland lakes seems to be having an impact on productivity."

Kaplan has been studying the nesting behavior of loons at Isle Royale National Park. Located in Lake Superior, the 850-square-mile island is America's least-visited national park, which, ironically, may make its loons more vulnerable to human disturbance.

"Isle Royale's inland lakes are wilderness lakes and have nonmotorized use only," Kaplan explains. "Use levels aren't high. But the loons may not get used to people's patterns, so when people do show up, the loons overreact."

This overreaction takes the form of abandoning their nests and any eggs therein. Often enough, the parents never return, and the eggs never hatch.

It doesn't take much to spook a loon. Many pairs leave their nests when they notice people as far as 150 meters away. "I've seen them flush 275 meters away," Kaplan says.

What makes loons so vulnerable to canoes is their aquatic nature. Unlike ducks and geese, loons can't walk on dry land, so their nests must be on the water's edge. That puts them near canoe routes and portages.

The good news is that when people are kept away, the loons rebound quickly. Last year, the National Park Service moved a portage in Isle Royale National Park away from a loon nest site, and the pair stayed on their nest. And when canoes are warned away from nesting areas by buoys, loons are more likely to hatch their eggs.

"That's exactly what you want to see," Kaplan said. "In the absence of canoe use, we predict about 70 percent of nests will be successful."

Kaplan sees the loons' vulnerability to disturbance as a cautionary tale in the annals of natural resource management.

"It's kind of assumed that wildlife are protected in wilderness areas," he says. "That's not necessarily true."

"This is one small story to add to the growing body of evidence that protection doesn't necessarily guarantee conservation," says Kaplan. "The remedy is informed management.

"It will be interesting to see how far people will go to protect those values that prompted us to create wilderness areas in the first place."

"Long-term studies like these help us make good management decisions," said Phyllis A. Green, Isle Royale National Park superintendent. "We were pleased to support this study, which revealed important information about a species in decline."

In conducting his research, Kaplan relied in part on 12 years' worth of data collected by the National Park Service on the number of loon chicks hatched on the island. He compared that data with information on the number of back-country canoe and kayak permits issued since 1991.

The survey of loon chicks is undertaken every summer by park service staff and volunteers, including Kaplan, who has been observing loons at Isle Royale for 10 years.

Kaplan's research is funded by the National Park Service, the North American Loon Fund, the Sigurd Olson Environmental Institute and Bonnie Robbins.