Document Type

Honors Thesis

Publication Date

Spring 2019


In an attempt to increase alternative energy sources, there has been greater development of wind farms across the United States. This expanded development may pose a potential threat to birds that are flying overhead (EIA 2017, Leung and Yang 2011). More information is needed on the factors that affect a bird’s behavior while flying and if the current policies and dimensions of wind turbines interfere with flight altitudes. We used data from GPS-marked great blue herons (Ardea herodias) in Maine to classify their flight altitudes relative to wind turbine height and assess different landscape factors that affect flight altitude. We found an altitude range of 1 m to 924 m, compared to a range of wind turbine heights in Maine from 24 m to 156 m, with 43% of observed flight altitudes falling within that range. We found elevation, speed, proximity to open water and wetlands, and the proportion of surrounding urban development and forest cover to have a positive effect on flight altitude. Slope had a negative effect on heron flight altitudes. Our results can help to better understand how the flying behavior of birds is affected by the surrounding landscape, and therefore how that behavior may be affected by human developments, such as constructed wind turbines.