Target Detection by Echolocating Bats

Abstract

Echolocating bats form a highly diversified group. Their different types of sonar signals have been proposed as a base for classification and identification (e.g. Simmons and Stein, 1980, Ahlèn, 1981). The “design” of the sonar pulses of a given bat species is believed to reflect adaptations or trade-off’s between various properties such as detection sensitivity, ranging, clutter and noise rejection, and inconspicuousness. Operating at the lowest signal to noise ratio, with parameter estimation being higher order processes (Urick, 1983, Altes, 1984) detection can be argued to be the fundamental process of a sonar. Measures of detection sensitivities — or detection thresholds — therefore are informative characteristics of the sonar of a given bat species.