Swinny’s horseshoe bat lives in groups of around five individuals, although many groups may congregate in a roost. Very little is known of their behaviour, diet or reproductive cycle (3).
The horseshoe bats have highly-developed echolocation systems which are able to decipher Doppler-shifted echoes. The Doppler shift is the change in pitch heard when the source of a sound and its receiver are either getting closer together or further apart. If a source of sound and an individual hearing that sound are getting closer together, the receiver will hear a higher pitched sound than if they remained at a constant distance. As a bat flies towards its prey, it is listening for the echo of the pulses of sound it emits. These echoes increase in frequency as the bat approaches its prey. However, horseshoe bats have an optimal frequency of sound to which they are especially sensitive and so to ensure their echoes return at this frequency, they compensate for the Doppler shift by emitting a lower frequency; the faster they fly, the lower the pitch (5). For Swinny’s horseshoe bat, the echo will always return at 115 kHz, although the frequency of the emitted sounds varies with flight speed (3). Whereas other bat species cannot emit and receive echolocation signals at the same time, being able to compensate for the Doppler shift enables horseshoe bats to use longer, overlapping calls to build up a more detailed picture of their cluttered forest environment (5).