Echolocation: its impact on the behaviour and ecology of bats

Echolocation is an active system of orientation involving the production of pulses of sound which are compared to echoes returning from the surroundings. Bats comprise the order Chiroptera, and while echolocation is a feature apparently common to all species in the suborder Microchiroptera, only one species in the suborder Megachiroptera is known to echolocate. Furthermore, not all echolocating bats use the same specific approach to echolocation. The short range nature of echolocation may be the reason why most Microchiroptera are small. Small size has metabolic consequences such as high metabolic rates and high energy demands. This, in turn, means that bats eat a great deal and many species exploit concentrations of food. Species in two families, the Rhinolophidae and Vespertilionidae, use heterothermy to minimize thermoregulatory costs and this affects the reproductive patterns of these bats. While echolocation does not appear to be energetically expensive in terms of sound production, the signals make bats conspicuous to other bats and to their prey. Information leakage affects many aspects of bats' behaviour. Bat morphology often reflects echolocation, from pinnae that may be tuned to the frequencies in echolocation calls, to species with large ears for collecting low frequency sounds associated with the movements of prey. Noseleafs affect the patterns of sound emission. Bats that depend upon the sounds of prey often do not rely on echolocation for locating and assessing targets, and the role of echolocation in the lives of fruit, nectar and pollen, and blood feeding bats remains unclear. Echolocation and its attendant specializations are components in the ongoing debate about whether or not bats are monophyletic.