Publication Date


Date of Final Oral Examination (Defense)


Type of Culminating Activity


Degree Title

Master of Science in Raptor Biology



Major Advisor

Jesse R. Barber, Ph.D.


Marie-Anne de Graaff, Ph.D.


Christopher J. McClure, Ph.D.


Oil and gas development has rapidly increased across the world over the last several decades. Anthropogenic noise, an invisible pollutant that alters animal distribution and behavior, could be responsible for documented wildlife population declines near loud compressor stations in energy extraction fields. We experimentally played back compressor noise, creating a “phantom natural gas field” in a large-scale experiment, and tested the effects of noise on songbird distributions during the breeding season and on arthropod distributions. Further, to begin to understand the influence of noise produced by different types of extraction infrastructure, we examined the effects of sound intensity and bandwidth, or the amount of frequencies emanating from a noise source, on bird and insect abundance.

Breeding songbird distributions were negatively affected by broadband, high sound level noise exposure. We observed a 25.9% decrease in abundance of the songbird community and three individual species showed declines in noise. Our results further show that higher intensity and bandwidth are positively associated with the arthropod abundance of most groups, where for instance sap-feeders, omnivores, and grazers increased over 30% with increased sound levels. In contrast, lower intensity and bandwidth playback was negatively associated with arthropod abundance, where omnivores and grazers decreased over 19% with increased sound levels. Noise could impact trophic relationships in the sage steppe ecosystem. Any increase in herbivore arthropod species, could intensify herbivory, resulting in changes in plant chemistry. We demonstrate the importance of understanding the potential landscape-scale costs of noise exposure and the acoustic structure of noise on wildlife.


Available for download on Wednesday, August 21, 2019