Department of Natural Resources tags loons to study effects of oil spill
Wildlife experts fearful that the call of Minnesota's iconic loons could be silenced on many of the state's lakes because of the oil spill in the Gulf of Mexico worked through the night Monday to outfit a pair of the birds with GPS transmitters.
A group from the Minnesota Department of Natural Resources and the U.S. Geological Survey tagged two loons on separate lakes southwest of St. Cloud to study the effect of the Gulf spill on the state's loon population, Minnesota DNR Nongame Wildlife Program Supervisor Carrol Henderson said Tuesday.
"It will say two things," Henderson said after returning to his St. Paul office after a tagging expedition that wrapped up at sunrise Tuesday. "First, it will tell us where they are going, whether it's the Atlantic coast or the Gulf Coast. Second: Do they die or do they come back?"
Studies show that most of Minnesota's loon population migrates to the Gulf Coast for the winter.
Henderson said loons migrate south in October and November. Adults return in April, but young loons stay for two years before heading back to Minnesota.
When the Gulf oil spill occurred April 20, the majority of loons had already migrated back to Minnesota.
The birds will return to the Gulf this winter.
Loons spend much of the winter in the water, Henderson said.
"We know many of them are going right to the area where the oil is coming ashore," he said. "This is not the kind of problem that will be gone when the birds migrate. We expect some mortality. We just don't know how much."
Minnesota's loon population has held steady at about 12,000 for several years, Henderson said.
He fears the Gulf oil spill could trigger a steady decline in numbers.
But there is hope.
Henderson points to danger faced by bald eagles, ospreys, peregrine falcons and brown pelicans 50 years ago from the chemical DDT. He said they are examples of birds that bounced back from significant population declines.
"We've seen it happen before," he said. "But in the case of those birds, it took 20 to 25 years to recover. We hope it wouldn't take that long."
The U.S. Fish and Wildlife Service reported last month that of the 1,500 birds found dead or soaked in oil, only one was a loon.
Minnesota's two loons tagged with GPS monitors Monday will be part of a U.S. Geological Survey project to track 10 loons from Minnesota and Wisconsin.
Loons will also be closely monitored by more than 1,000 volunteers as part of the 17-year-old Minnesota Loon Monitoring Program, said Minnesota DNR nongame technician Katie Haws of Bemidji. The program focuses on six areas throughout the state. Each area focuses on 100 lakes.
Information from transmitters on the 10 loons used in the U.S. Geological Survey study will be immediately available.
The rest is a waiting game.