From the Yellowstone Valley Flyer, the newsletter of the Yellowstone Audubon Society -
Power poles and transmission lines are a threat to large birds, especially birds of prey that use the structures as perches. How much of a threat is not precisely known. but according to a National Biological Survey report, 25 percent of reported golden eagle mortalities over a 30-year period were caused by electrocution. Of the 1,238 raptor electrocutions counted in 10 western states between 1982 and 1995, half were golden eagles. Part of the problem is that utility companies are replacing older wooden poles with steel poles, which have the advantage of durability and low cost but which can also conduct electricity. It is possible to retrofit the poles so that raptors cannot be electrocuted, but the cost is high , and so the modification is seldom undertaken.
The number of reported electrocutions probably represents only a small part of the real mortality.
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