Syracuse, N.Y. -- A bike trail extension near the Destiny USA mall could chase away bald eagles that have just begun staying along the Onondaga Lake shore year-round, environmental groups say.

The new trail route proposed by Onondaga County on land known as Murphy's Island would run closer to the water and right under the big cottonwood trees where eagles have been seen, an Audubon representative said.

"We know from direct evidence if a trail goes in close to the shoreline, and if it's open to the public throughout the relatively mild part of the year, the bald eagles are going to be disturbed," said Chris Lajewski, of Audubon New York. "There's a potential there that we may lose the bald eagle roost as a result."

The return of bald eagles to the lake shore -- as many as 39 at a time during the winter -- has been heralded as proof of the success of the $1 billion-plus lake cleanup. So too has the county's Loop the Lake Trail, which wraps from Onondaga Lake Park around the north side and west sides of the lake.

County officials said the new trail route across the 40-acre Murphy's Island is safer than the original one, which they decided was too close to the railroad tracks. The county's environment director, Travis Glazier, said he's been assured by federal officials that the new route beneath the trees in which the birds perch won't violate the 1940 law that protects bald and golden eagles.

Onondaga County initially proposed building a bike trail (blue line) on Murphy's Island along the railroad tracks, but has now moved the proposed trail (orange line) closer to the lake and through the trees were bald eagles perch. At the bottom of the photo is Destiny USA.

The U.S. Fish and Wildlife Service, in a letter to the county in April, said the trail could be built without disturbing the eagles if it was closed in the winter, when the eagles roost there.

"They stand by their position that if (the trail) is closed Dec. 15 through March 15, it's going to preserve the eagles," Glazier said.

The birds, which eat fish, are likely attracted to the area because the warm outflow from the county's sewage treatment plant keeps the water ice-free in winter.

Lajewski notes, however, that the Fish and Wildlife memo only addresses the winter presence of eagles, and the birds are now seen there all year. In fact, Lajewski said, when Glazier gave him and county Legislator Michael Plochocki a tour of Murphy's Island last month, they flushed three eagles from the cottonwood trees.

"We believe that human foot traffic on the island is likely to disturb the eagles roosting and resting there," Lajewski said.

Glazier said advocates for the eagles misunderstand what the federal law means by "disturbing" the eagles. That only applies when the eagles are gathered together during the winter, he said. The birds mate and nest in winter.

"When bald eagles are flushed from a perch not in the roosting period," Glazier said, "it does not constitute a disturbance, according to the Fish and Wildlife Service."

It's Glazier that has it wrong, said Alison Kocek, president of Onondaga Audubon. She points to the Fish and Wildlife Service's National Bald Eagle Management Guidelines, which state that any "human activity (that) agitates or bothers roosting or foraging bald eagles" can violate the eagle protection act if that activity interferes with breeding, feeding or sheltering.

Kocek said the eagles could be chased away from their roosting and foraging areas near the lake if people start riding bikes and walking through the trees on Murphy's Island.

"The probability that the birds would persist if a high number of people use that trail on a regular basis would be pretty low," she said.

A group that formed last month, Friends of the Onondaga Lake Bald Eagles, said they plan to address county legislators at Wednesday's month. They plan to ask the county to halt plans for the trail and turn Murphy's Island into a bald eagle sanctuary instead.

The meeting begins at 1 p.m. on the fourth floor of the county courthouse. Legislators won't vote on the plan Wednesday.

One of the group's organizers, Diana Green, said the presence of the eagles so close to the mall is a tourism draw that the county should preserve.

"People come from miles away to view eagles, Green said. "When people come from other places to view eagles, they stay overnight, they buy food, they do shopping."

Advocates for the eagles note that when the county Legislature in December approved spending $1.5 million to build the trail, legislators asked county officials to try to put the trail near the railroad tracks and away from the bald eagle roosting area.

Glazier said that further study showed that a trail near active train tracks would be dangerous, even if the county built a fence or even a solid sound barrier.

"It's a public safety hazard," he said.

Murphy's Island is also highly polluted by decades of industrial dumping. A 2009 study found that cancer risks would be higher than allowed by federal guidelines for people who frequently walked through Murphy's Island. Building a trail would make the site "healthier" because contaminated land will be covered over, said Ryan McMahon last year, when he was chairman of the Legislature. He is now county executive.

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