The effect of recording situation on the echolocation calls of the New Zealand lesser short-tailed bat (Mystacina tuberculata Gray)

Using a broad-band recording system (150 Hz-100 kHz) the echolocation calls of the lesser short-tailed bat (Mystacina tuberculata) were recorded under three very different situations: free-flying, flying within a flight cage, and on release from the hand. Calls of bats landing and feeding on a platform in Wellington Zoo were also recorded. Both the lowest frequency and frequency of peak amplitude of calls were significantly affected by the situation under which calls were recorded. Although the calls of free-flying bats are different from those produced by bats foraging on the ground, it is unlikely that M. tuberculata uses echolocation to locate prey on the ground. No significant differences could be found between the calls emitted by male and female bats, and no consistent relationships were obvious between temporal and spectral call characteristics. There was some evidence to suggest that individual bats could be identified by their echolocation calls.