The Effect of Transmission-line Corridors on Bird Populations

Observations of bird populations were made along transmission-line corridors of four different widths (12, 30.5, 61, 91.5 m) in areas in which the' transmission-line rights-of-way traversed typical eastern Tennessee deciduous forest. In addition, detailed grid-mapping of individual birds was conducted in forest and in a 30.5 m-wide corridor habitat. Narrow corridors (12 m) had reduced bird species diversity, but the 30.5 m corridor had high bird density and diversity. The wider corridors were less diverse but attracted several open-country bird species not characteristic of surrounding forest. Significance of the effects of the 30.5 m corridor on the distribution of 35 bird species was determined. The highest species diversity was associated with the forest habitat.