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Summary: Bergmann et al. (1988) formed the tentative hypothesis that the spatial distribution of different "rain call" dialects in the Chaffinch (Fringilla coelebs) could be caused by the acoustic environment. In concrete terms, it was supposed that the "huit" call was used predominantly in urban districts with a high level of traffic noise because this type of sound is more capable of penetrating the traffic noise. In order to test this hypothesis, a study was conducted in the towns Remscheid, Solingen and Wuppertal. Analysis of traffic noise showed that the sound pressure decreases with ascending frequency and reaches an insignificant value between 4,0 and 5,0 kHz. In view of the hearing capability of the Chaffinch it seemed that "rain calls" with frequencies of 4,5 to 7,0 kHz are best for piercing traffic noise. However, the main frequencies of the "huit" call do not exceed 4,2 kHz, which means that an adaptation to traffic noise is improbable. In addition to this the rain calls of different dialects were classified into noise zones. No dependence of dialect on traffic noise intensity could be established. Summing up, the cautious hypothesis of Bergmann et al. (1988) could not be corroborated. [ABSTRACT FROM AUTHOR]

The article focuses on a study conducted by researcher P. J. Wensveen and his colleagues, concerning the response of humpback whales on sonar being used by navies in the Barents Sea in north Norway. Information regarding the efficiency of the warning strategies, the risk of inducing hearing loss due to intense sound source and pressure, and the reluctance of humpbacks to avoid sonar, are mentioned.