A survey of cetaceans found in Mayo Bay, Davao Oriental, Philippines

Cetaceans play an important role in marine ecosystems through the regulation of their prey population. Data on these organisms is scarce because of the difficulties in studying them in the wild. In the Philippines, there is a large gap in knowledge in cetacean research. Short-term studies, including those on strandings, play an important role in addressing the gaps in cetacean research. Boat-based surveys of cetaceans were designed and conducted to create a database of cetaceans in Mayo Bay, Davao Oriental, Philippines. Globicephala macrorhyncus, Peponocephala electra, Stenella attenuata, Stenella longirostris, Tursiops truncatus,  and Lagenodelphis hosei cetacean species were encountered during the short-term survey, with Stenella longirostris being the most common cetacean species. Moreover, cetacean strandings within Mayo Bay recorded at least three species that were not observed in the wild during the boat-based survey. This study provided additional information on at least six data-deficient cetacean species of the Philippines and perhaps new information on a species belonging to the genus Mesoplodon in the Philippines, highlighting the importance of Mayo Bay for cetacean research and the need for further investigations in the region.