Ja. Williams et al., THE ABUNDANCE AND DISTRIBUTION OF BOTTLE-NOSED DOLPHINS (TURSIOPS-TRUNCATUS) IN DOUBTFUL SOUND, NEW-ZEALAND, Canadian journal of zoology, 71(10), 1993, pp. 2080-2088
Photographic identification and standardized zigzag surveys were used
to study the distribution and abundance of bottlenose dolphins in Doub
tful Sound, New Zealand. Forty individuals were identified from nicks
and markings on their dorsal fins. Chapman's and Bailey's modification
s to the Lincoln - Petersen estimate and the computer program CAPTURE
were used to estimate the number of marked individuals in the populati
on, which ranged from 30 to 40 animals for three survey periods (two s
ummers and a winter). The proportion of identifiable individuals in th
e population was assessed empirically as 65.5%. These data resulted in
a total population estimate of approximately 58 individuals. The majo
rity of the dolphins in the catalogue were found in each survey period
, indicating their residency in the fiord. Movements of dolphins aroun
d the sound were not predictable, but there were areas in which dolphi
ns were more likely to be found and other areas in which dolphins were
never seen. However, there were no obvious seasonal or daily movement
patterns.