United States

United States

Watching over bats, birds and bears

Ecologists are scrutinising the US wind industry beyond the familiar avian issues, following reports of bat deaths in Minnesota and fears that bear behaviour in Vermont is being affected by the state's lone wind plant of 11 turbines on Waldo Mountain.

Wally Erickson from Western Ecosystem Technology Inc in Wyoming says 11 bats of different species were found dead in 1994 and 1995 along access roads to the Buffalo Ridge wind farm in Minnesota. It consists of 73 Kenetech KVS 33 wind turbines. No dead bats were found last year. Nevertheless, Midwestern environmentalists are voicing concern about a large bat colony located near a proposed wind project near Green Bay, Wisconsin.

Meanwhile, a group of Vermont citizens is grappling with the issue of man made technologies being introduced in wilderness areas, according to Nicholas Goodman, a graduate student at the University of Vermont. Goodman presented a paper at the American Wind Energy Association's annual conference in June that examined the environmental issues surrounding the remote Waldo Mountain wind farm, owned by Green Mountain Power.

Researchers have strung a strand of barbed wire across a known bear crossing near the site to catch hairs. This method does not harm bears, said Goodman, but allows researchers to tell which direction the animals are travelling. From this monitoring system, researchers found a slight decrease in bear activity during project construction, but then returning to normal since then.

Meantime, after researching the Buffalo Ridge wind development, Western Ecosystem says it has little impact on bird populations. Erickson reports only four birds were found dead within an eight month monitoring programme. None were raptors -- the primary concern of most environmentalists. One was a common mallard duck and three others were small passerines. Erickson notes that found birds generally represent 25% of actual kills, and mortality estimates are scaled up for entire project areas. Thus, from data collected at the site, which consists primarily of agricultural land and wooded ravines, approximately 186 birds are killed annually -- a "relatively low" mortality rate, says Erickson. Among the bird species of top concern near the site are a flock of 900 cormorants as well as large numbers of Lapland Larkspurs.

He points out that an avian monitoring plan being developed for the 425 MW of new turbine installations to serve Northern States Power is the most thorough in the country and will continue for a minimum of four years. Beyond monitoring bird deaths at the forthcoming 100 MW Zond project in the northwestern part of Buffalo Ridge and future development sites in the region, a control study area in Brookings County, South Dakota, is also under surveillance. "We will evaluate the accumulative risk [to bird populations] with each phase of development," Erickson says.

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