Sonic Patterns I: The Noise - Soundscape Ecology: Principles, Patterns, Methods and Applications - page 163

Loss of population % Loss of population %

100 100

0-100 m 0-500 m 0-1500 m 0-100 m 0-500 m 0-1500 m

80 80

60 60

40 40

20 20

0 0

Fig. 6.12 Loss of population of different species of birds according to the number of cars/day
at a mean speed of 120 km/h: 5,000 cars/day ( left ); 50,000 cars/day ( right ) (Reproduced with
permission from Reijnen et al. 1996 )

finally to broadband computer-generated noise (Fig. 6.13 ). The highly repellent
effect of vegetation noise (12 dB below traffic noise) probably depends on the
acoustic similarity between prey sounds and vegetation noise with a stronger
masking effect.

6.16 Noise as a Signal in Marine Environments

The marine soundscape is modified by anthropogenic intrusion by shipping and
small boats, drilling and mining seismic surveys, and by offshore wind farms, and
this impact can mask important natural sonic cues. For instance, we expect in future
years that the receding of ice will cause further intrusion of human activity in the
polar regions, accompanied by increased ambient noise in summer months by
seismic air-guns associated with oil and gas exploration, in areas densely populated
by blue, fin, and sperm whales (Klinck et al. 2012 ).
Orientation, habitat selection, and predator avoidance are supported by the use of
acoustic information across the animal kingdom. In particular, communication in
invertebrates is of great importance for their survival and maintaining the complex
food chains.