ABUNDANCE AND SEASONAL RESIDENCE OF SPERM WHALES AT KAIKOURA, NEW-ZEALAND

Photographic identification was used to document patterns of occurrenc e of individual sperm whales in the deep nearshore waters off Kaikoura , New Zealand. Between 1988 and 1993, 86 individuals were identified f rom nicks and marks in the trailing edge of their flukes. All individu als photographed were uniquely identifiable and no substantial changes in mark occurred over the study period. Resightings show that some wh ales spend several weeks or months in the area. Half have been seen in more than one field season. One individual has been seen every year f rom winter 1989 to winter 1992, and like several others appears to ret urn to the area regularly. Others (35%) have been photographed on 1 da y only and may be transients. Almost all (88%) of our sightings were o f single whales. We used ''open'' capture-recapture models to estimate the size of the population that visits Kaikoura. These models suggest an average population of between 60 and 108 individuals present in an y one season.