Rediscovery of short-tailed bats (Mystacina sp.) in Fiordland, New Zealand: Preliminary observations of taxonomy, echolocation calls, population size, home range, and habitat use
Cfj. O'Donnell et al., Rediscovery of short-tailed bats (Mystacina sp.) in Fiordland, New Zealand: Preliminary observations of taxonomy, echolocation calls, population size, home range, and habitat use, NZ J ECOL, 23(1), 1999, pp. 21-30
Short-tailed bats (Mystacina sp.) were rediscovered in Nothofagus dominant
rainforest in the Eglinton Valley in February 1997, representing the first
records of these bats in Fiordland since 1871. Breeding females, adult male
s and juveniles were captured. This paper presents preliminary observations
of taxonomy, echolocation calls, population size, habitat use, activity pa
tterns, home range size, movements, roosting, and singing behaviour. Compar
ed to lesser short-tailed bats (M. tuberculata) on Codfish and Little Barri
er Islands, the Fiordland bats were heavier, had larger wings and smaller e
ars, and were sexually dimorphic. The Mystacina echolocation calls were of
low intensity (quiet), making them difficult to detect. Call durations in f
ree-flying bats were only 1.0-2.9 ms long. In a comparative trial the major
ity of calls that were detected at 25 kHz using the Batbox III bat detector
were not recorded at 40 kHz, indicating that there was little overlap with
the calls of long-tailed bats (Chalinolobus tuberculatus). In February, ro
osting groups numbered from 107 to 279 individuals and the bats ranged over
130 km(2) of the valley. Bats began emerging c. 20 minutes after sunset an
d were active at the roost sites throughout the night. Radio-tagged bats we
re active for an average of 372 minutes at a time. All roosts were in large
diameter (67-146 cm dbh) red beech (N. fusca) trees.