Thursday, April 24, 2014
Two juvenile female peregrine falcons captured and released this fall from Monhegan Island are providing wildlife biologists with new information for siting offshore wind-power projects.
Two juvenile peregrine falcons were captured on Monhegan Island this fall and fitted with satellite transmitters that allowed biologists to follow their migration route from Maine to Cuba and Columbia.
Courtesy photo by Al Hinde
Chris DeSorbo, raptor program director for the BioDiversity Research Institute, and Rick Gray, raptor program field coordinator, hold an American kestrel on Manana Island in September 2010.
Courtesy photo by Al Hinde
MORE INFORMATION on the Biodiversity Research Institute migration research is available online at
Both birds were fitted with satellite transmitters and released on separate days in October before making the flight down the East Coast to Cape Hatteras, N.C., in less than a week. The birds then shot across the water to winter quarters in Cuba and Colombia.
The BioDiversity Research Institute in Gorham is studying the migratory habits of falcons, saw-whet owls and eider ducks as part of an unprecedented international network of research aimed at understanding bird migration in the region and how it might be affected by offshore wind-power projects now under development.
Researchers are scrambling to figure out the flight paths of different migratory bird species to help guide siting decisions for the 400-foot-high wind turbines that could soon sprout in the Gulf of Maine.
The University of Maine has identified three offshore test sites for floating turbines that are due to start operating next year. With Interior Secretary Ken Salazar's announcement last month of plans to speed up the siting of offshore wind projects in the Atlantic, trying to keep the potentially lethal turbines away from migration routes has gained new urgency for biologists.
"BRI is really helping to fill in some of the pieces of the puzzle," said Rebecca Holberton, a University of Maine professor who is leading the Gulf of Maine's Northeast Regional Migration Monitoring Network.
The network also includes the U.S. Fish and Wildlife Service, the Maine Department of Inland Fisheries and Wildlife, Maine Audubon, Nova Scotia's Acadia University and the National Audubon Society's Seabird Restoration Program.
The institute's saw-whet research was led by wildlife biologist Kate Williams, who found the species last year in an unexpected spot -- Isle au Haut off Penobscot Bay.
This year, Williams set up eight research stations from Lubec to Cape Elizabeth to count saw-whets -- robin-sized owls that weigh about a fifth of a pound -- as they moved from Canada and northern Maine to their wintering grounds in North Carolina, northern Georgia and Alabama.
For the first time, biologists documented that the owls were traveling over the ocean at night, rather than over land as previously suspected.
"This is one of the amazing scientific moments of discovering something," said Williams.
The falcon research took place on Monhegan Island, where biologists counted birds during four weeks of the fall migration as the speedy raptors made their way through Maine from points north to wintering grounds as far south as Argentina. More than 800 birds of prey, three-quarters of them falcons, were counted. The falcons included peregrines, merlins and kestrels.
Chris DeSorbo, BRI raptor program director, said the falcons were following their food source -- other birds -- as they moved south. The researchers caught 25 of the falcons, and measured, sampled and banded them. Two were fitted with satellite transmitters that are too heavy for other species.
They discovered the birds flew almost identical paths, sometimes spending more than a week at a time over open ocean. Together, the two birds traveled more than 6,400 miles.
DeSorbo said he will be following the birds over the next year and analyzing the data to find out at what altitudes they fly, and whether they started out from the cliffs of Greenland, as DeSorbo suspects.
Maine's eider duck population is also being studied. Maine and Alaska are home to the largest eider breeding grounds in North America. Maine's estimated population of 25,000 eiders congregate in huge groups up to a quarter mile from the coast, where they feast on a plentiful supply of blue mussels.
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The BioDiversity Research Institute s wildlife biologists counted saw-whet owls like this one along the Maine coast this fall.
Courtesy photo by Tony Oppersdorf