Wind Turbines & Birds Myth
I'll state right up front that in the past, some wind turbines in avian flight paths did have a track record for killing birds. In fact, bird lovers used to call these "avian Cuisinarts" in order to get their point across.
Since around the year 2000, however, the design of utility scale wind turbines has changed greatly with lower blade speeds and more visibility. The assumption that wind farms are still today killing a large number of birds has turned into a myth.
Sure, those with a political agenda of not wanting a wind farm to go up in their neighborhood will still cite wind turbine bird kills as if it were current fact. But, along with the few bird strikes that do occur to turbines, the critics rarely compare that number to the number of automobiles flying down the highways, killing birds or the number of airline bird strikes.
The very nature of many birds is to live a haphazard and short life. About 30-percent of all birds don't make it past their first year of life due to collisions with different parts of nature such as boulders, mountainsides or falling from tree branches.
In fact, older birds are commonly killed everyday by flying into non-natural structures such as skyscrapers and the windows of other buildings, homes, trees, electrical fences and many other places. A typical 1.5 mW wind turbine with large surface area, slow moving blades is more likely to receive a bird strike on its shaft as it is on one of the blades.
The top threat to birds outside of wind turbines include the electrical grid, vehicle collisions, buildings and residences, communication towers, pesticides, cats, jet engines, smoke stacks and bridges.
A study in the 1980's found that 69 millions birds migrated through the San Gorgonio Pass near Palm Springs, California. Of this number, only 38 bird deaths were attributed to the local wind turbines.
This means the bird mortality rate due to wind turbines in a migratory pathway was statistically insignificant. More birds were killed in one moment in the jetliner crash that landed safely in New York's Hudson River than were killed over one year in the San Gorgonio Pass in California.
The bird-o-matic myth actually started with a reality and that is at the Altamont Pass in California where older, smaller faster spinning turbines have been used. This one wind farm counts for a disproportionately high number of avian deaths. Constructed in the 1970s the Altamont Pass wind turbines contain around 4900 smaller generators that are gradually being replaced with larger, slower bladed turbines.
Wind turbine manufacturers have responded to criticism first by constructing larger wind generators with slower blades. They have also experimented with different colored paints and reflective devices to ward off birds. The sound of the turbine itself is another early warning system to birds flying nearby.
The myth of wind turbines killing birds continues to this day. The reality, however, is that wind turbines are a safe and clean method to produce renewable energy and are necessary if we are to break our addiction to foreign oil.
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