Biology Reference
In-Depth Information
The seismic prospecting in terrestrial ecosystems produces a disturbance to wild
animals that is not easily evaluated by the traditional methods of line transect counts
of individuals, dung, nest sites, or other biological signs. For instance, Wrege
et al. (
2010
) have proposed an automatic acoustic survey able to collect information
about movements and vocalization of populations of forest elephants (
Loxodonta
cyclotis
) in Gabon, Central Africa in an area disturbed by oil prospection. Ten
autonomous recording units (ARU) were dispersed in the area in which oil research
was active. The ARU had a microphone and a geophone to collect seismic activity
and sounds in atmosphere. Results indicate that elephant distribution and seasonal
abundance and frequency of vocal emission apparently were not changed during
blasting activity, but elephants had shifted their activity during the night, and the
change toward nocturnal activity was increased with the increase of human prox-
imity. This change in behavior would have escaped the traditional approach of
censusing, demonstrating how acoustical monitoring represents an innovative and
efficient system to detect changes in animal behavior that are the forerunner of
long-term population dynamics.
Evidence of the negative effect of energy facilities was reported by Baynes
et al. (
2008
) for boreal forests of Alberta, Canada. In the areas in which there were
silent-energy facilities, the density of passerine community was 1.5 times greater
than in the areas with noise-energy facilities. In particular, the white-throated
sparrow (
Zonotrichia albicollis
), yellow-rumped warbler (
Dendroica coronata
),
and red-eyed vireo (
Vireo olivaceous
) had lower density in noise areas.
6.19 Wind Turbines and Noise
Electricity-generating wind turbines (windfarms) are a modern system to produce
renewable and no-emission energy. Their impact on the landscape is at least of
three types: visual (aesthetic), physical (the blades impact with migratory birds and
raptors), and acoustic. This last aspect has been for a long time neglected but
represents in wild and mountains areas an important source of sonic pollution.
The effect of noise produced in these windfarms alters the sonic environment to
which residential animals may be sensitive.
Wind turbines are new devices that in some areas become the dominant scenic
and sonic elements. Their rotation capture human eyes and their sonic emissions are
important for the soundscape and the landscape. It is well known that vision
influences environmental noise perception and vice versa, and that the noise
annoyance is greater when the source of noise is visible.
In a study conducted on the form of noise barriers, the more pleasant barriers
were considered a minor annoyance that was attributed to the noise traffic. After
this example it seems reasonable to predict that seeing wind turbines and hearing
their noise should produce the highest rate of annoyance, but if the wind turbines
are evaluated positively by a social assessment, the annoyance should decrease.
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