[BCNnet] bird mortality factors and wind power

[bobolnk at ix.netcom.com]

The GAO has released a review of the impacts of wind turbines on bird populaitons.  They concluded that while it doesn't appear that wind turbines in general cause significant mortality to bird populations, there are exceptions. Also they emphasize that we do not have enough information about their impacts to be confident of the conclusion.  If you'd like to read the report, it's at 

http://www.gao.gov/new.items/d05906.pdf

Here are some excerpts - I thought the paragraph that summarizes bird moratility figures was interesting. 

FWS estimates that some of the leading sources of bird
mortality, per year, are collisions with building windows—97 million to 976
million bird deaths, collisions with communication towers—4 million to 50
million bird deaths, poisoning from pesticides—at least 72 million birds,
and attacks by domestic and feral cats—hundreds of millions of bird
deaths. Human activities also result in the destruction or modification of
wildlife habitat; habitat loss and fragmentation are leading threats to the
continued survival of many species.

 FWS and the U.S. Geological Survey have
recently initiated a study of bird and bat migration behaviors to address
some of these data gaps. This study will use radar technology to
characterize daily and seasonal movements and habitat and landform
associations of migrating birds and bats, and will seek to develop decision
support tools to provide assistance in identifying locations for wind
turbines and communication towers

researchers recommended that sodium vapor lights should never
be used at or near wind power facilities because they have commonly been
shown to attract birds to other structures. They noted that the largest
number of birds killed at one time near wind turbines was found adjacent
to sodium lights after a night of dense fog. No fatalities have been
discovered near these turbines since the lights were subsequently turned
off.

FWS law enforcement officials told us that the way they have handled avian
mortalities at wind power facilities is similar to how they deal with wildlife
mortality caused by other industries. These officials explained that FWS
recognizes that man-made structures will generally result in some level of
unavoidable incidental take of wildlife and, as a result, FWS reserves a level
of “enforcement discretion” in determining whether to pursue a violation of
federal wildlife law. Law enforcement officials told us that before FWS
pursues civil or criminal penalties, the agency prefers to work with a
company to encourage them to take mitigation and conservation steps to
avoid future harm. If a company shows a good-faith effort to reduce
impacts, FWS will likely not refer such a case for prosecution. If, however,
a company repeatedly refuses to take steps suggested by FWS, officials
said they are likely to refer it for prosecution