Volker Bahn (Committee Member), Jeffrey Peters (Committee Member), Thomas Rooney (Advisor)
Master of Science (MS)
Noise is an under-appreciated source of pollution that can influence the spatial distribution of birds. In this study, I examined how noise frequency and intensity (both background noise (kHz) and decibel levels (dB)) affected avian richness, density, and number of birds that sing with the same frequency as anthropogenic noise (low note frequency). I also examined the responses of two species in detail, the Eastern Wood Pewee and the Acadian Flycatcher, because they lack song plasticity. I examined whether they responded to noise by avoiding "noisy" areas or shifting their song frequency. I examined the response of bird communities to site, distance-from-edge, decibel level, and background noise. Decibel levels and distance-from-edge both influenced avian richness. Where decibel levels were high, avian richness increased with distance from edge. Where decibel levels were low, avian richness is highest at the edge and decreased towards the interior. As decibel levels increased, avian richness decreased. Avian density differed among sites and in response to noise. As decibel levels increased, the avian density decreased. Germantown Metro Park site had a higher avian density than Blendon Woods and Huffman Metro Park. Avian density decreased as decibel level increased at both Blendon Woods and Huffman Metro Park. Avian density was unchanged at Germantown Metro Park, even with increasing decibel levels. Decibel level and distance-from-edge influenced lowest note frequency. Where noise intensity was highest, there was a corresponding increase in the lowest note frequency. There was a slight increase in lowest note frequency as distance-from-edge increased. The lowest note frequency was highest at the edge where noise intensity was greatest, and lowest at the edge were noise intensity was least. The distribution and lowest note frequencies of Eastern Wood Pewee and Acadian Flycatcher were not influenced by site, distance-from-edge, background noise, or decibel level. Forest edge, decibel level, and background noise interact to shape avian communities.
Department or Program
Department of Biological Sciences
Year Degree Awarded
Copyright 2018, all rights reserved. My ETD will be available under the "Fair Use" terms of copyright law.