C. hectori

Cetaceans are reported to respond to stress by displaying vertical avoidance behaviour, increasing dive duration, changing swimming direction and increasing swimming velocity. Dolphin groups are also reported to become more compact with erratic swimming speeds and directions of travel. Hectors dolphin is the smallest member of the family Delphinidae and is endemic to New Zealand. Volume 1 (of III), introduces Hectors dolphin and the subject stress as relates to cetacean species. This volume outlines the first comprehensive study, undertaken at Lyttelton and Timaru, which used a non-invasive observation method to record C. hectori behaviour in relation to the presence and absence of specific tour boats within these two New Zealand harbours. The study showed that Hectors dolphin has a strong preference towards particular watercraft and exhibit specific behaviours in the presence and absence of tour boats. Their location within each harbour was also mapped. This volume represents the primary results of a six year long study of Hectors dolphin behaviour at Lyttelton and Timaru and as such provides valuable insight into their biology.