title: An environmental limit on absolute auditory sensitivity in non-aquatic vertebrates.
abstract: It is proposed that ambient noise of environmental origin ultimately limits, at a common level, the lowest auditory thresholds found in both the non-aquatic mammals (including man) and in the most sensitive birds, the owls (Strigiformes). Greater sensitivity than that found in these vertebrates is unlikely to have evolved since it would be of little or no adaptive value. However, whether sensitivity in a particular species actually approaches this limit depends upon the species' evolutionary origins, and upon its period of activity within the day.
authors.affiliation: Department of Zoology and Comparative Physiology, University of Birmingham, P.O. Box 363, Birmingham B15 2TT, England; Department of Extramural Studies, University of Birmingham, P.O. Box 363, Birmingham B15 2TT, England.
authors.forename: G R
authors.initials: GR
authors.lastname: Martin