TRAVERSE CITY -- A year ago dead birds littered area Lake Michigan beaches, but it's been much different so far this year to the pleasant surprise of researchers.
"We were expecting to have lots and lots of dead birds to deal with, so it's good news that we haven't seen that," said Damon McCormick, a biologist with Common Coast Research and Conservation.
McCormick found seven dead common loons and a small group of dead red-necked grebes along the southern coast of the Upper Peninsula about six or seven weeks ago, but little since then, he said.
It's the same in other areas.
"By this time last year we had lots and lots of kills," said Mark Breederland from Michigan Sea Grant.
Breederland spent parts of last week walking about 10 miles of shoreline in Emmet, Charlevoix and Antrim counties, all sites where large numbers of birds died from botulism poisoning last year. He found just one carcass in Wilderness State Park near the Straits of Mackinac and another the week before in northern Antrim County, he said.
"Our phone lines would be ringing if we had big die-offs and we're just not seeing it," Breederland said.
This year so far brought three small confirmed outbreaks, in Mason County in June and July, in Emmet County in July and in Oceana County in August, said Tom Cooley, wildlife biologist with the Michigan Department of Natural Resources.
Botulism poisoning killed an estimated 7,500 native and migrating birds -- loons, ducks, gulls, cormorants and endangered piping plovers -- last year along shorelines between Sleeping Bear Dunes National Lakeshore, the Straits of Mackinac and along the southern coast of the Upper Peninsula. An outbreak of the disease was blamed for the deaths of about 2,600 birds in fall 2006 near the dunes.
Area environmental groups organized training sessions for "beach rangers" toward the end of summer, to prepare volunteers to help assess the extent of bird die-offs and learn proper disposal methods for dead birds. They were ready for another ecological tragedy.
"I think it might still be too early. The migration is still under way," said Gary Rentrop of Cross Village, a beach ranger who inspects two miles of beach about three times every week.
Rentrop found just a couple of dead birds in an area where 80 carcasses were found last year, he said.
Experts believed the bird deaths likely were a chain reaction from invasive species, including zebra and quagga mussels and round gobies.
The theory was that mussels filter the water, allowing more light to grow more cladophora algae, which hikes chances for botulism outbreaks. Birds could be poisoned and die by eating infected fish and mussels, as well as scavenging carcasses and maggots on the beach.
But with the lake still full of invasive mussels and gobies, that mechanism theory for avian botulism poisoning may need to change, McCormick said.
"The question for our neck of the woods is: was last year an anomaly or is this year a reprieve before something more permanent and extensive?" he said.
Breederland said changed variables this year include higher water levels and a slower rise in summer water temperatures in Lake Michigan.
"As is the case with nature, things change from year to year. The ecosystem is changing with invasive species and climate change, which is why continued research is critical," said Peg Comfort, coordinator of the local botulism network.
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