Abstract: Few studies have examined the home range characteristics of coastal dolphins or porpoises in detail. The location data of 40 Indo-Pacific humpback dolphins (Sousa chinensis) from Hong Kong waters and Lingding Bay, with a range of 10-67 sightings each, were analyzed. Range size of individuals varied greatly from 24 km² to 304 km², with an average of 99.5 km². Each estimated range encompassed only a small portion of the overall population’s range. Age class, association with a fishing boat, distribution and availability of food resources, and human activities and disturbances all influenced ranging patterns of humpback dolphins in the Pearl River Estuary. Seasonal and annual variations in range use were observed among individual dolphins. While providing information previously unknown about these dolphins, this study also indicated that further investigations are needed to identify the exact ranging patterns and home range characteristics for this humpback dolphin population.

Key Words: HUMPBACK DOLPHIN; SOUSA CHINENSIS; RANGING PATTERN; MOVEMENTS; HOME RANGE; PEARL RIVER ESTUARY; HONG KONG

Document Type: Research Article

DOI: 10.1578/AM.30.1.2004.159