Verditer Flycatcher Songbird

  Previously i had discussed the general impacts of humans on the natural soundscapes in national parks, however, i didn’t go to in-depth into the effects that humans have on wildlife, when soundscapes are disturbed. Often times this is referred to as Chronic Noise Exposure, which impacts how wildlife functions day-to-day. Noise inhibit the perception of sounds, this is effect is called masking, one sound is out playing another. One main impact is that increased noise levels in natural areas reduce the distance and area at which sounds or signals can be heard by animals. We are discussing this current issue in one of my classes. Our professor explained it like this, imagine a song bird is in a giant dome, they can hear everything around( in every direction) for about a hundred feet. Once human noise is introduced, the span of the dome of hearing for the songbird  is decreased by almost half the size. When they decrease the distance and area they can hear, they lose the ability to hear food, predators and danger past a  certain distance.

     The noise created by humans (walking, talking, aircraft, recreational vehicles,etc.) is referred to as anthropogenic noise, which has been shown to cause shifts in the animals behavioral patterns. Transportation has the largest impact on wildlife of the various types of anthropogenic noise. Human transportation has increased drastically in the last several years with traffic on roads increasing to almost triple the size, and air traffic is increasing dramatically also. Along with transportation, resource extraction from protected lands and recreational vehicle usage are big contributors to noise in natural areas. The disturbance of the natural soundscapes in parks is affecting not just the visitor experience but also the wildlife in these areas, with the potential to permanently harm populations and biodiversity.

   For more information on how human noise is affecting wildlife in parks and protected areas visit: http://buildingblogsofscience.wordpress.com/2009/10/29/how-is-human-noise-affecting-the-environment/

Yosemite National Park

      In the management policy 4.9, the National Park service  has made it a law that they must do what they can to preserve the natural soundscapes within the parks. They define a soundscape as the total acoustic environment of an area, both natural and human sounds that may be desirable and appropriate in a soundscape depending on the purpose and values of the park. In a class i am currently taking we are studying the issue of soundscape management in depth and are participating in a study that is testing the affects of human generated noise in National Parks. There are numerous studies that are being conducted to assist the park service in figuring out just what to do about this particular issue. Some reasons it is an important issue to study are first of all the concern over effects of noise in parks, secondly opportunities to hear natural sounds are diminshing, and lastly visitors aspire to hear natural silence in parks.  These studies have found various impacts of sound on the parks, that include: Visitors are shown to be willing to pay to avoid noises of recreational vehicles, as opposed to going to a free area where they may encounter such vechicles. Also, air tour noise (airplanes, helicopters, etc) dramatically effects the visitors experience, however it eliminating air tours all together would have a drastic effect on the local economy. This is another issue within figuring out how to manage soundscapes, how do they balance allowing some noise with eliminating all together and affecting other things. Lastly, it has been shown that undesirable noise within parks has negative effects on cognition (the ability to learn) emotion, motivation and health in general.  Clearly this is an issue worth looking into.

Great Smoky Mountains National Park