An analysis of pilot whale vocalization activity using hidden Markov models

Popov V, Langrock R, DeRuiter SL, Visser F. An analysis of pilot whale vocalization activity using hidden Markov models. The Journal of the Acoustical Society of America. 2017;141(1):159-171

Differences in Acoustic Signals from Delphinids in the Western North Atlantic and Northern Gulf of Mexico

Whistle characteristics were quantitatively compared between both geographically separated and neighboring populations of Atlantic spotted dolphins (Stenella frontalis), bottlenose dolphins (Tursiops truncatus), and pilot whales (Globicephala spp.) in U.S. waters to evaluate if intraspecific acoustic differences exist between groups. We compared nine whistle characteristics between continental shelf and offshore Atlantic spotted dolphins in the western North Atlantic and between northern Gulf of Mexico and western North Atlantic bottlenose dolphins and pilot whales using discriminant analysis. Offshore Atlantic spotted dolphin whistles were significantly different (Hotelling\u27s T2,P= 0.0003) from continental shelf whistles in high frequency, bandwidth, duration, number of steps, and number of inflection points. Atlantic bottlenose dolphin whistles were significantly different (Hotelling\u27s T2, P \u3c 0.0001) from those in the Gulf of Mexico in duration, number of steps, and number of inflection points. There was no significant difference between pilot whale whistles in the two basins. The whistle differences indicate acoustic divergence between groups in different areas that may arise from geographic isolation or habitat separation between neighboring but genetically distinct populations of dolphins. This study supports the premise that acoustic differences can be a tool to evaluate the ecological separation between marine mammal groups in field studies

Marine mammals of the Northeastern Caribbean Windward Dutch islands: Saba, St Eustatius, St Maarten and the Saba Bank

At least 33 native species of marine mammals have been documented from the Wider Caribbean Region (WCR). For many of these species, the waters of the region serve as primary habitat for critical activities that include feeding, mating and calving. However, relatively little remains known about their biology, life history, distribution and behavior, particularly also around the windward Dutch islands (Saba, St. Eustatius and St. Maarten). In this study we compiled 84 marine mammal records for the waters of these islands, comprising 9 previously published records and 75 new records. A total of eight distinct species are documented, six of which are cetaceans. In comparison to the leeward Dutch islands (Aruba, Curaçao and Bonaire), documented strandings are few. Results suggest that whereas beaked whales and Bryde’s whale are more common around the leeward Dutch islands, humpback whales are more common around the windward Dutch islands. This study concludes that more dedicated efforts are needed to better document and understand cetacean composition, seasonality and use of the both the windward and leeward Dutch Caribbean maritime territories. Such initiatives should help further clarify any potential regional differences as well the underlying causes thereof. Several nations, including the USA, the Dominican Republic and France, have established marine mammal sanctuaries in their Caribbean waters. Declaring the Dutch EEZ as a marine mammal sanctuary would be a valuable contribution to the conservation of marine mammals in the region