Cannons, lasers used to try to scare birds from disease-ridden natural area
The Smith and Bybee lakes wetlands in North Portland are among the gems of Metro's natural areas systems.
But an avian botulism outbreak, larger than any state officials say they've seen in Oregon, has wildlife managers scrambling to scare birds away for now.
The outbreak, which poses little threat to humans, is killing more than 100 birds on some days, and the problem keeps getting worse. It was first noticed in early September, when a Metro biologist reported seeing dead green winged teals.
Metro, which owns the Smith and Bybee Wetlands Natural Area, is doing everything from shooting cannons to flashing green lasers in an effort to keep birds away from the lakes for now.
"We're using it as a method to keep the birds mobile as much as possible," said Don VandeBergh, a biologist with the North Willamette Watershed District of the Oregon Department of Fish and Wildlife.
The botulism outbreak is a naturally-occurring incident, and ODFW veterinarian Colin Gillin said he doesn't think it has anything to do with the landfill next to which Smith and Bybee sit. Gillin said the bacteria that causes the disease lives naturally in soils; sometimes, bugs become carriers of the bacteria.
If a bird eats a bug infected with the bacteria, it, too, becomes a carrier. The bacteria produces a toxin that can cause a loss of nerve function in birds, Gillin said. If one duck died of botulism poisoning, it would then be eaten by maggots, which become meals for other birds.
Before long, the whole area is a trap for any birds stopping by, and the lake itself is full of the toxin.
"These things will continue until the weather cools down or you start to get rain," Gillin said. "If you can get all the water out of those wetlands and dry it up in a hurry, the birds won't land and the outbreak would stop."
Metro natural areas land manager Dan Moeller said Bybee Lake has already been drained. Moeller said staffers are working with ODFW to figure out how to drain Smith Lake, which has many beaver dams impounding its water. He said Metro works with Ducks Unlimited to draw down the lakes for weed control on an annual basis.
Gillin said this is one of three notable current outbreaks of avian botulism in the United States, with the others in Minnesota and Maryland. Neither Gillin nor VandeBergh remember an outbreak this large happening in Oregon, although botulism outbreaks do occur with regularity across the state.
VandeBerghe said the outbreak seems to be confined to the Smith and Bybee Lakes area for now. Workers at nearby Sauvie Island have been watching for signs of the outbreak spreading but haven't seen any indication of that.
Gillin said the outbreak poses little threat to humans.
"It's a different type of botulism that affects people," he said. "Unless you're drinking the water or eating fly larvae, your risk is nearly zero."
The hazing started Tuesday and is expected to last as long as 10 days, and includes explosives, air horns, sirens, lasers, paintball markers and people on boats scaring off waterfowl. The goal, said VandeBergh, is to scare the birds off in a way that they don't get acclimated to.
Metro has a $5,000 contract with the U.S. Department of Agriculture to conduct the hazing operations.