Friday, August 10, 2007

PS 72-160: Measuring the impacts of noise on lekking greater sage-grouse

Jessica L. Blickley, Diane J. Blackwood, and Gail L. Patricelli. University of California, Davis

Animal acoustic signals are adapted to the acoustic environment in which they evolved, so as human development increasingly alters the acoustic landscape, acoustic communication may be masked or disrupted.  Despite the ubiquity of anthropogenic noise, little is known about noise impacts on wildlife and how animals may adjust their signals in response to anthropogenic noise. We are investigating the impacts of noise from natural gas development on breeding greater sage-grouse, a species of management concern across western North America that uses acoustic communication in mate choice. Sage-grouse are declining in areas of natural gas development, and there is circumstantial evidence that noise from development may be a cause of this decline. To test this hypothesis, we are experimentally introducing noise to 8 sage-grouse leks (4 drilling noise and 4 road noise) and monitoring 8 as controls. This experimental approach will allow us to separate out the effects of a change in acoustic environment from other confounding factors associated with increasing development. Noise impacts will be assessed through analysis of lek attendance patterns and behavioral observations of sage-grouse on experimental and control leks. We have completed two seasons of experimental noise introduction and observation on sage-grouse leks near Hudson, WY.  We will discuss preliminary results, as well as methods for assessing both the masking potential of noise and how individuals might adjust their vocalizations to compensate for noise.  This research provides a unique opportunity to experimentally address the impacts of anthropogenic noise on avian behavior and communication while also informing management decisions for a species of conservation concern.