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At a time when the world is facing an oil crisis, our concern is directed to sustainable renewable forms of energy. One such source of energy is power generated from wind turbines. Wind power is not without it's drawbacks, one of these being concern over the impact it has on bird's migratory patterns.
Wind turbines are responsible for the deaths of between 58,000 and 440,000 birds. That sounds very impressive; but in reality that only accounts for about one-tenth of one percent of all "abnormal" bird deaths in the United States each year. Even though experts associate wind turbines with bird mortality, the majority of research establishes that wind turbines kill comparatively few birds when compared to other man-made structures. This does not mean that we should not take into consideration the bird mortality rate, but those setting up wind farms should consider taking safety measures as well.
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Who/What in Fact is Killing the Birds?
Wind turbines may perhaps be responsible for the deaths of 33,000 birds per year. In case of electrocutions, the number of these birds is great especially rare birds like raptors. The recent upsurge of interest in wind power has compounded fears about the outcome on birds, which has ultimately led to discussions regarding the wind power industries taking more effort to design bird-caring windmills. Locations selected to set up wind turbines should be ones that are less "birdie." (For statistics about bird mortality and the steps taken by UNEP please visit wind-watch).
Albert Manville, a bird expert with the Fish and Wildlife Service, when questioned to compare the number of birds killed due to wind turbines with those killed by windows, cats and cars stated thus:
“Comparing bird deaths from wind turbine collisions and barotraumas to other sources of mortality — e.g., building windows, vehicles, cats, or communication towers — is akin to trying to compare apples to kumquats. It confuses and muddies the waters. The bigger issue is one of cumulative impacts, specifically what mortality factor will become the proverbial ‘straw that breaks the camel’s back.’ Will it be wind energy, new building windows, oil spills, or other source(s)? We simply don’t know. While wind mortality may presently be relatively low, impacts are all about risk. The blade-caused collision death of one whooping crane becomes an impact to its entire population." (Source: Are wind turbines really that bad for birds?)
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How is a Bird Killed when It Comes into Contact with a Windmill?
A wind turbine with speedily whirling blades invokes a bird, clubs it, and then reduces it to a mist of floating plumages. A lot of birds die when they ram into turbine blades. Nevertheless this is not the single way by which wind farms kill birds: birds bump against turbine towers and power lines also, and the building of wind turbines wipes out bird nesting and feeding environments, at times cutting down the quantity of obtainable food. Wind farms built in bird migration paths are especially disturbing.
The true fact is that no one actually knows the exact number of birds that die each year due to the developing wind power industry. Most research so far has concentrated only on one or two wind farms and several do not consider the count of birds killed considering the quantity of energy produced. Additionally, studies may sometimes overvalue the death toll when the information is collected from a place or time where/when the number of birds that die is used to foretell the mortality rate for large areas and longer duration, or is miscalculated as the carcasses of the birds fall in harsh or boggy terrain, or is omitted as the birds may have be devoured by scavengers before the data is gathered. Wind turbines are dangerous, but we need alternative source of energy as well. So both birds and wind turbines have to go hand in hand, and this can be achieved by following safety measures when constructing wind mills.
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Cell Phone Towers and birds
Apart from wind turbines killing birds, manmade structures also play a vital role in butchering countless birds every year. Death to birds results when they collide with cell phone towers. Nevertheless, while at the same time it is not easy to track the real number of communication towers built nationally, the facts evidently depict an enduring exponential growth of cellular telephone use. Established on present data, more than 100,000 illuminated communication towers that are more than 61 m above ground level can be seen in the U.S. today.
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How Do Communication Towers Kill Birds?
Since nearly all birds move around at night the main threat is created by lighted towers. When birds come across lighted constructions their nocturnal piloting ability can become puzzled. They ring the structure again and again, unwilling to go away from the lighted area. The birds thus crash against the guy wires, or with the tower, or even with each other. A lot of the birds killed actually represent species that are by now in decline. The figures and genus identified to be involved are in all probability merely the tip of the iceberg. Estimates of the number of birds actually killed are unfeasible due to the lack of data, but it could easily be more than 5 million birds per year. More information can be found at FLAP and Towerkill.
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Conclusion and References
We as human beings can avoid this kind of huge bird mortality by taking some precautionary measures when building wind farms and towers. What we can do to help the speechless birds are as follows.
In the future, wind power growth can kill even fewer birds if the right safeguards are taken:
- More research has to be undertaken so that better and accurate data on the definite bird death toll due to wind power can be gathered.
- Building of wind farms on bird migration routes should be avoided.
- Wind farms should also not be constructed in areas where large numbers of birds congregate for any cause.
- The height of wind turbines should be between 200 and 260 ft. so that blades can be placed at heights where birds do not tend to fly.
- Possible rests for birds should not be provided by turbines or towers.
- At places where bird hits are probable, turbines should be closed down when visibility is bad.
Similar to wind turbine safety, communication towers can also take the following safety measures to avoid bird killing:
- Avoidance of guy wires at these towers can reduce the bird mortality rate.
- Careful consideration has to be taken when selecting the location for towers.
- Migratory and flyways birds have to be considered when the height of the tower is being designed.
- Areas of bird concentration have to be avoided.
- As many towers as possible can be left unlit.
Diane Katz - Windmills Kill More Birds
John Ritter - Wind turbines taking toll on birds of prey
Matthew Lasar - Will the FCC ever deal with bird-killing mobile phone towers?
Ed Arnett - Wind Energy - Friend of Foe?