Greater Yellowstone Ecosystem Report
As human populations have increased, our impact can now be felt even in the deepest remnants of wilderness (Vitousek et al. 1997). The resource demands of the ever-increasing human enterprise are creating substantial amplification of man-made pollution, including noise production. The dominant sources of anthropogenic noise are transportation networks, development (including energy, urban and industrial) and recreational activities. These activities are increasing faster than population growth. Between 1970 and 2007 the US population increased by approximately one third whereas (http://www.census.gov/compendia/statabO traffic on US roads nearly tripled, to almost 5 trillion vehicle kilometers per year, (http://www.thwa.dot.gov /ohim.tutw/tvpage.cfm.) Similar trends in shipping noise have also been observed in marine ecosystems, as discussed in reviews of noise impacts on marine animals (e.g., Nowacek et al. 2007).
Barber, J. R.
"Chronic Anthropogenic Noise Exposure and Songbird Hearing,"
University of Wyoming National Park Service Research Center Annual Report: Vol. 31
, Article 10.
Available at: http://repository.uwyo.edu/uwnpsrc_reports/vol31/iss1/10