'Green' wind turbines prove deadly for bats
The Province|Cheryl Chan|September 25, 2008
Bats and wind turbines make a bad mix. In fact, bats have become an unexpected casualty in the burgeoning wind-power industry, with several thousand bats killed by turbines each year in North America. Now studies are being conducted at the future site of a Peace region wind farm in order to save bats from dropping dead near the whirling blades. ...Most of the wind-farm research has been focused on birds, and little is known about the effect on bats, although new studies are beginning to yield clues on how to minimize the impact of the wind farms on the tiny flying animals.
Bats and wind turbines make a bad mix. In fact, bats have become an unexpected casualty in the burgeoning wind-power industry, with several thousand bats killed by turbines each year in North America. Now studies are being conducted at the future site of a Peace region wind farm in order to save bats from dropping dead near the whirling blades. ...Most of the wind-farm research has been focused on birds, and little is known about the effect on bats, although new studies are beginning to yield clues on how to minimize the impact of the wind farms on the tiny flying animals.
PhD student found that air-pressure drops burst tiny animals' lungs
Bats and wind turbines make a bad mix.
In fact, bats have become an unexpected casualty in the burgeoning wind-power industry, with several thousand bats killed by turbines each year in North America.
Now studies are being conducted at the future site of a Peace region wind farm in order to save bats from dropping dead near the whirling blades.
A two-month study monitored the numbers and migratory routes of the mammals at Bear Mountain Wind Farm near Dawson Creek, which hosts numbers of silver-haired bats and hoary bats.
"We want to gather more information . . . to see what things we might do if there are a lot of bats coming through the area," said Jim Bracken, …
... more [truncated due to possible copyright] PhD student found that air-pressure drops burst tiny animals' lungs
Bats and wind turbines make a bad mix.
In fact, bats have become an unexpected casualty in the burgeoning wind-power industry, with several thousand bats killed by turbines each year in North America.
Now studies are being conducted at the future site of a Peace region wind farm in order to save bats from dropping dead near the whirling blades.
A two-month study monitored the numbers and migratory routes of the mammals at Bear Mountain Wind Farm near Dawson Creek, which hosts numbers of silver-haired bats and hoary bats.
"We want to gather more information . . . to see what things we might do if there are a lot of bats coming through the area," said Jim Bracken, senior vice-president of major projects for Alberta-based AltaGas.
Most of the wind-farm research has been focused on birds, and little is known about the effect on bats, although new studies are beginning to yield clues on how to minimize the impact of the wind farms on the tiny flying animals.
It was commonly believed that bat deaths were caused by collisions with the towers or rotor blades. But a recent University of Calgary study reveals that the deaths are caused by sudden drops in air pressure near the rotating blades, which can reach speeds up to 250 km/h.
The research team examined 188 bat carcasses found at the Summerview wind farm near Pincher Creek, Alta.
About half had no external injuries.
Out of 75 dissected corpses, 90 per cent showed signs of internal hemorrhaging consistent with "barotrauma," or tissue damage caused by a rapid change in air pressure.
"We found that air-pressure drops near turbine blades led to the air sacs in the bats' lungs and lung vessels to fill with blood and burst," said Erin Baerwald, a PhD student and lead author of the study, published in this month's Current Biology journal.
Bats have balloon-like lungs, with delicate air sacs, that can over-inflate when the pressure drops, bursting the capillaries around them, explained Baerwald.
In comparison, bird lungs are more rigid and better able to withstand sudden changes in air pressure.
About 600 dead bats a year are found near the Pincher Creek turbines.
It is not known why bats are attracted to the turbines, but research reveals they tend to avoid the structures in high winds. One possible solution proposed by Baerwald's study is to boost the speeds of the turbines.
The Bear Mountain study is the second study conducted by AltaGas following a three-month study last year. The farm, which will operate 34 turbines, is expected to begin operation in November 2009.