2013年3月21日 星期四

Observatory prepares for spring radar study of migration

With one eye on the federal government’s budget situation, Mark Shieldcastle, research director at the Black Swamp Bird Observatory, is hopeful there will be another radar study this spring of the flight patterns of migratory birds along the Lake Erie shoreline.

Data from a study conducted in the fall is still being analyzed.

“We were kind of surprised by some of the preliminary results from the fall study – by how the birds were moving,” Shieldcastle said. “There was a lot more movement along the coast at night than they expected. They thought everything would be just going across but they are following the coast very similar to what they do during the day. You would think at night they are migrating across the lake but they found an awful lot of birds that are actually following the coastline to the west, just like they would during the day.”

The U.S. Geological Service provided two radar units and Bowling Green State University provided another for the fall phase of the study that began last spring but with only two radar units.

Personnel from the U.S. Fish and Wildlife Service, the Ohio State University, University of Toledo, and the observatory have also been participating in the study, which ultimately hopes to gain insight into whether the flight patterns would place the migrating flocks close to wind turbines that have been or soon will be erected near the lake shoreline.

Radar can give researchers a look at the patterns of movement and volume of the birds, their elevation, and how they’re interacting with the lake and shoreline, Shieldcastle said.

One question in particular needs to be addressed, he said: Are they flying above the risk zone – the area around the blades of the turbines?

One radar unit was placed close to the shoreline while the others were three and 15 miles inland. Preliminary data from the unit farthest inland are yielding another surprise.

“That unit had a huge amount of activity below 500 feet,” Shieldcastle said. “How that compares to right along the coastline we don’t know yet. But they weren’t expecting that much bird activity that low 15 miles inland. That can be a very important piece of information, depending on how that analysis comes out. One possible explanation is the birds are dropping in just like a jet comes in – on a long approach. That’s still up in the air until the data is analyzed. But it does show the birds follow a lower altitude farther inland than was thought.”

The Black Swamp Bird Observatory hosted a forum last year, inviting researchers from academia, government, and conservation groups, to update their peers on projects they’ve undertaken in the Great Lake region.

Participants also discussed how radar studies could be included with other strategies such as banding, counts, and acoustic monitoring in a cost-effective manner.

But the researchers also renewed their call for additional study of the migratory flight patterns along the lake before wind energy development is pursued. In particular, they’ve asked for a three-year moratorium on the placement of wind turbines within three miles of Lake Erie in Lucas, Ottawa, Sandusky, and Erie counties.

BSBO staffers have been watching development at the Lake Erie Business Park, which has been promoting its site as well suited for wind and solar energy. Wind turbines have been installed at two schools in the Oregon City School District.

Shieldcastle said there has been research on the effect of turbines on migratory birds but most of the studies have been conducted in areas where birds are in active migration and some portion of the flocks are flying well above turbine blades.

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