Year: 1981
Type: article
Abstract: AaSTaAcT.-Thetasks in a census of singing birds include: (1) identification of the species of a singer, and(2) estimation of the location of the singer.The acoustical properties of the environment interfere with both these tasks; effects depend on the type of habitat.In open fields the primary sources of degradation are attenuation and amplitude fluctuations.Attenuation limits the maximum range of detection, and alters the frequency composition of the sound as heard by the observer.Fluctuations are random, and interfere with amplitude modulation.They may also cause error in estimation of distance.In forests attenuation has a similar effect, though the exact values depend on the type of forest.Reverberation is of major importance as a source of sound degradation, and virtually obliterates the fine details of songs at moderate distances, interfering with recognition.Sound scattered by trunks and foliage also makes estimation of the location of the singer more difficult.Adaptations by birds to combat the effects of song degradation by the environment may both help and
Author: Richards, Douglas G.
Language: English
Domain: Life Sciences
SDG: Life on land
Open Access status: green
OpenAlex ID: W7028257484