University study says wind turbines threaten migrating bats

A Pacific Northwest bat that that migrates south for the winter faces a serious threat from wind turbines, according to a study by the by Oregon State University-Cascades.

Posted: Sep 23, 2019 11:33 AM
Updated: Sep 23, 2019 11:33 AM

BEND, Ore. (AP) — A Pacific Northwest bat that that migrates south for the winter faces a serious threat from wind turbines, according to a study by the by Oregon State University-Cascades.

The study concludes that the hoary bat faces an uncertain future because its numbers have declined by 2% per year, the Bend Bulletin reports.

Collisions with propellers on wind farms kill bats, said Tom Rodhouse, one of the authors, an ecologist with the National Park Service and a courtesy faculty member at OSU-Cascades.

Another cause is barotrauma, which occurs when bats fly through low pressure zones created by the spinning blades of a wind turbine. The sudden change in pressure causes their lungs to expand faster than the bats can exhale, resulting in burst vessels that fill their tiny lungs with blood, Rodhouse said.

"This and direct collisions with the turbines has resulted in millions of bat deaths over the last two decades," said Rodhouse.

Oregon and Washington have 3,600 wind turbines that generating capacity of 6,300 megawatts. Most wind farms are clustered near the Columbia River Gorge. Others are near Ellensburg and Walla Walla in Washington and Baker City in Oregon.

While migrating, hoary bats fly into danger zones because their sophisticated sonar capabilities do not detect the pressure drops, Rodhouse said.

Barotrauma has similarities to decompression sickness experienced by divers. Lungs of birds are more rigid, with strong capillaries, making them less vulnerable to the pressure changes near wind turbines.

White-nose syndrome, a disease that has killed bats elsewhere, is not affecting the hoary bat, Rodhouse said.

Hoary bats are named after their white-tipped fur coats, which look frosty. They hunt at night and feed on pests that eat crops. The animals are slow to reproduce in the Pacific Northwest, with females producing just one to three pups per year, Rodhouse said.

Cris Hein of the U.S. Department of Energy's National Renewable Energy Laboratory said there are ways to combat the problem.

Technology to protect the bats includes ultrasonic deterrents that that may prevent bats from approaching the wind turbines. Another option is to turn off turbines in late summer and fall when bats are migrating.

The study was published in Ecology and Evolution.

Oregon Coronavirus Cases

Data is updated nightly.

Cases: 207558

Reported Deaths: 2760
CountyCasesDeaths
Multnomah40446614
Washington26850249
Marion23497324
Clackamas18981235
Lane13944166
Jackson11581146
Deschutes1005582
Umatilla862787
Linn565381
Yamhill479479
Klamath478278
Polk402056
Douglas391683
Josephine363872
Malheur362063
Benton327522
Jefferson237839
Coos217737
Columbia193029
Union150224
Wasco145630
Lincoln144021
Crook129523
Hood River121933
Morrow115816
Clatsop10639
Baker103115
Curry73211
Tillamook6614
Grant5527
Lake4698
Harney4369
Wallowa1945
Gilliam811
Sherman701
Wheeler351
Unassigned00

California Coronavirus Cases

Data is updated nightly.

Cases: 3812825

Reported Deaths: 63501
CountyCasesDeaths
Los Angeles124841524472
Riverside3017994627
San Bernardino2994254886
San Diego2820523778
Orange2731705116
Santa Clara1202332199
Kern1108471405
Sacramento1080131738
Fresno1030201724
Alameda898911286
Ventura817271032
San Joaquin748081440
Contra Costa70882813
Stanislaus635861071
Tulare49823850
Monterey43858456
San Mateo42756581
San Francisco37304559
Santa Barbara34631455
Solano33797267
Merced32325481
Sonoma31026317
Imperial28908741
Placer23656300
Kings23214247
San Luis Obispo21448261
Madera16660245
Santa Cruz16262209
Marin14212230
Yolo14161212
Butte12666198
Shasta12615235
El Dorado10423117
Napa1003280
Sutter9676113
Yuba652151
San Benito611163
Lassen580825
Tehama574263
Nevada493675
Humboldt452849
Mendocino435750
Tuolumne422271
Amador374347
Lake356653
Glenn243727
Siskiyou239938
Colusa228818
Calaveras221056
Del Norte14688
Inyo143438
Mono12984
Plumas7426
Modoc5645
Mariposa4667
Trinity4246
Sierra1180
Alpine890
Unassigned330
Medford
Partly Cloudy
65° wxIcon
Hi: 98° Lo: 59°
Feels Like: 65°
Brookings
Partly Cloudy
53° wxIcon
Hi: 84° Lo: 60°
Feels Like: 53°
Crater Lake
Partly Cloudy
65° wxIcon
Hi: 79° Lo: 45°
Feels Like: 65°
Grants Pass
Partly Cloudy
65° wxIcon
Hi: 101° Lo: 60°
Feels Like: 65°
Klamath Falls
Partly Cloudy
54° wxIcon
Hi: 87° Lo: 50°
Feels Like: 54°
Dangerously hot weekend ahead
KDRV Radar
KDRV Fire Danger
KDRV Weather Cam

Community Events