PS 78-150 - Impact of various road types and trails on bird abundance and diversity at Black Rock Forest, Hudson Highlands, New York

Friday, August 11, 2017
Exhibit Hall, Oregon Convention Center
Terryanne Maenza-Gmelch, Environmental Science, Barnard College, Columbia University, NY, NY and Marissa Wasmuth, Environmental Science, Barnard College, NY, NY

Black Rock Forest and surrounding preserves in the Hudson Highlands of New York were designated as an Important Bird Area by Audubon New York in 2016. We are interested in understanding the impacts of various road types and trails on bird abundance and diversity in order to inform land-use decisions in and near this forest for bird conservation purposes. Three sites were targeted for this study: forest near paved road, dirt road and trail. All three sites were similar except for their location in relation to the road type. Five points were randomly established at each site. Each point was visited several times during the period spanning May 18, 2015 to June 30, 2015, totaling 30 minutes at each point.


A total of 692 detections were made of 57 bird species in this survey. Measures of bird species richness and Shannon-Weiner Index of Diversity were not significantly different between paved road, dirt road and trail (with 15.2, 19.6, 15.2 mean richness, respectively and 2.61, 2.84, 2.63 mean SW Index, respectively and 176, 312, 204 bird dectections, respectively). All p values were > 0.1. Since the sample size was only 5, we plan to repeat this study next season with more sites.

Our results are similar to a previous study done ten years earlier at Black Rock Forest (Rothe et. al. 2005) that determined there were no significant differences in bird diversity and abundance along roads and trails at this forest. Since Black Rock Forest exists in a landscape matrix that is heavily forested in general, it is not surprising that the bird diversity and abundance near roads and trails may not differ significantly. An expanded analysis (to include more points, a forest interior site away from all roads and trails as a control and a separation of various nesting and foraging guilds) is planned.