Baird, R.W., A.M. Gorgone, A.D. Ligon and S.K. Hooker. 2001.
Mark-recapture abundance estimate of bottlenose dolphins (Tursiops
truncatus) around Maui and Lana'i, Hawai'i, during the winter of
2000/2001. Report prepared under Contract # 40JGNF0-00262 to the Southwest
Fisheries Science Center, National Marine Fisheries Service, La Jolla, CA.
Bottlenose dolphins were photo-identified in the area between the islands
of Maui, Lana'i, Moloka'i and Kaho'olawe, Hawai'i (an area of
approximately 3,000 km2) between November 2000 and March 2001. A total of
328 hours were spent on the water during 49 days, and bottlenose dolphins
were encountered on 32 occasions on 22 days. Fifty-nine individual
dolphins had long-term recognizable markings (dorsal fin or back notches),
and an additional 12 individuals (including 4 calves) were also documented
based on body scars, dorsal fin shape or pigmentation patterns; thus,
approximately 82% of individuals are thought to be recognizable in the
long-term. Identification data were combined with a catalog of 63
individuals that had been documented in the same study area in 1999 and
during the spring of 2000. During this entire period each "marked"
individual was documented an average of 3.6 times (range 1-16), though
individuals were not re-sighted randomly; some were seen more often and
some less often than expected by chance. A mark-recapture analysis of the
population using identifications from 1999 and from November 2000-March
2001, taking into account the proportion of marked individuals, produced
an estimate of 134 dolphins (95% CI = 107-179). Using modeled rates of
discovery the population was estimated at 122 individuals. Given the size
of the study area and the presumed transitory nature of bottlenose
dolphins around oceanic islands, the population in this area is
PDF copies can be obtained by writing to Robin Baird at email@example.com
Robin W. Baird, Ph.D.
Post-doctoral Fellow, Biology Department, Dalhousie University
Cetacean and Sea Turtle Team, NMFS, NOAA Beaufort Lab
101 Pivers Island Road, Beaufort, NC 28516 USA
e-mail: firstname.lastname@example.org or email@example.com
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