Breeding-bird population changes following right-of-way maintenance treatments

Abstract

The effects of herbicide and mechanical vegetation maintenance treatments on breeding-bird populations were compared on electric transmission rights-of-way (ROW) in the Allegheny Mountain and Piedmont Physiographic Provinces in Pennsylvania (hereafter termed the Allegheny ROW and the Piedmont ROW, respectively). Bird density decreased from pre-treatment (June) to post-treatment (August) in 1987 on handcut and mowed plus herbicide-treated ROW areas on both the Allegheny and Piedmont ROW; whereas, bird density increased on basal-, stem-foliage-, and foliage-sprayed ROW from pre- to post-treatment. A decrease occurred on the mowed ROW areas only on the Piedmont ROW. Retention of shrubby borders by selective treatment was a major factor in retaining the pre-treatment bird populations in the post-treatment period.