Almost any subject can be spun for political use and this just might be the case with bird loss and wind turbines. Often times one does not know what to believe. Not at all surprisingly, birds have some political clout in the wind arena. California is considering moving an entire wind farm due to the number of people rallying behind bird loss issues. In Massachusetts, there is a large group of opposition stalling the development of a Nantucket Island Wind farm.
Looking into this area, birds have it tough. Any number of things may cause their individual deaths or their collective demise. In nature, bird collisions and death are a rather common occurrence. Most of these death happen to younger birds. Overall, about 30% of total first-year bird deaths happen by collision. The biggest cause of bird death however is human infringement due to depleting the environment and collisions with person-made objects. So how much are we impacting the birds? The following list shows the approximate number of U.S. annual bird deaths and the cause.
Deaths due to collision:
- 300,000,000 - buildings
- 200,000,000 - free roaming cats
- 150,000,000 - transmission and distribution lines
- 70,000,000 - trucks and autos
- 60,000,000 - pesticides
- 50,000,000 - communication towers - doubling by 2010
As compared to wind turbines the bird mortality rate is about 2.0 birds per year per tower. Also, it is becoming more common practice to site new wind farm developments out of the way of migratory paths and the increased size of the turbine blades also minimize the chance of bird death on collision.