More than 1000 species of bats have the ability to navigate and track their prey for capture via echolocation. This active sensory system requires that the echolocating animal generates ultrasonic calls which in turn reflect off different objects creating echoes. Such returning echoes are processed by the auditory system of the bat to form an auditory scene that allows the bat to exploit dark foraging niches with little competition from visual predators.
Since Donald Griffin’s discovery of echolocation in bats, captive studies have uncovered several aspects of bat biosonar. These informative studies have mainly taken a reductionist approach via detailed neurophysiological lab studies. However, little is still known about more holistic, but highly pertinent, features such as the echo level required for a bat to detect a target. This information is essential since it is critically informative of the distance at which targets of varying size, shape and texture can be picked up by the bat’s auditory system, and hence inform transitions in motor and vocal patterns for target interception. Thus, quantification of performance features such as target detection, integration time, and ranging mechanisms has profound implications for understanding the natural behaviour of bats in the wild and how echolocation evolved.
For this PhD, I therefore propose to use state-of-the-art techniques to investigate key aspects of the sensory physiology of echolocating bats. I will (i) quantify the energy threshold required for a bat to detect an echo and test the hypothesis for dynamic integration time; (ii) examine the ability of bats to discriminate small distance differences of targets and (iii) identify potential drivers of vocal-motor flexibility during the buzz (i.e., the <1 s period before intercepting a prey).