AUTHORS: Kathleen Wadiak; Erica Holm; Matthew D. Tarr; Kevin Newton - University of New Hampshire
ABSTRACT. In the Northeastern U.S., thousands of miles of shrub-dominated transmission line rights-of-way (ROW) extend across the landscape and provide some of the largest and most stable shrubland habitats in the region. These ROW are used as nesting and post-fledging habitat by the region’s entire community of shrubland-dependent songbirds, but evidence for how ROW are used by songbirds that require mature forest for nesting is lacking. Mist-netting surveys conducted in regenerating clearcuts indicate that adult and fledgling mature-forest songbirds comprise a large proportion of the bird community in clearcuts during the post-fledging portion of the breeding season, a time when juvenile birds and molting adults require dense cover to avoid predators and abundant food resources to prepare for migration. In 2017, we began the first comprehensive mist-netting survey ever conducted in shrubby ROW in southern Maine and New Hampshire to inventory the entire community of songbirds using ROW during the nesting and post-fledging periods. In this preliminary year of our study, we investigated whether differences in the height, density, and species composition of plants between three ROW maintained by mowing and three ROW maintained with selective herbicide treatment resulted in differences in the community of shrubland-dependent or mature-forest dependent songbirds. We conducted six mist net surveys in each ROW from late May-late August and we caught a total of 83 adult and 49 fledging mature-forest birds and 520 adult and 340 fledging shrubland-dependent birds. There was no difference in the number or diversity of shrubland-dependent or mature-forest birds between the different ROW types. Certain mature-forest birds (e.g., scarlet tanager, ovenbird, wood thrush) were caught regularly in ROW throughout the breeding season. By the end of 2018 we will have surveyed a total of 24 ROW to further improve understanding for how ROW function as habitat for a variety of songbirds.
