Very little is known of the socio-behavioural dynamics of island-associated cetaceans, and even less about multi-species communities such as those seen in the Philippines. Tañon Strait is a large, semi-enclosed body of water in central Philippines, with pelagic characteristics and bound by two islands, Negros and Cebu, with a shallow northern opening, and a narrow southern opening. In my postgraduate research, equipped with photo-identification techniques, I investigate inter- and intra-species dynamics of several dolphin species inhabiting the strait; I estimate their demographic parameters and population size, and with the application of geographically referenced data I map their patterns of habitat preferences and range use. While working on several species, I place particular emphases on the Indo-Pacific bottlenose dolphin Tursiops aduncus as a species of a particular regional conservation concern, and the spinner dolphin Stenella longirostris, historically caught as by-catch in large numbers. These two species exhibit contrasting life history strategies; bottlenose dolphins are known to rely on coastal resources and shallow waters and tend to form smaller groups, while spinner dolphins form large groups of up to several hundred individuals and, contrary to other island-associated spinner dolphins elsewhere, in Tañon Strait they often aggregate in considerably deeper water. I am interested in how these animals respond to the availability (or lack) of important resources in this unique semi-pelagic habitat of the Strait and how this has shaped their behaviour and population structure. In a broader scale, this study will advance our understanding of the population structure and socio-spatial dynamics of island-associated cetaceans, which will in turn generate information directly applicable to their conservation as part of the management plan for the Tañon Strait Protected Seascape.