Behavioral context of echolocation and prey-handling sounds produced by killer whales (Orcinus orca) during pursuit and capture of Pacific salmon (Oncorhynchus spp.).

Availability of preferred salmonid prey and a sufficiently quiet acoustic environment in which to forage are critical to the survival of resident killer whales (Orcinus orca) in the northeastern Pacific. Although piscivorous killer whales rely on echolocation to locate and track prey, the relationship between echolocation, movement, and prey capture during foraging by wild individuals is poorly understood. We used acoustic biologging tags to relate echolocation behavior to prey pursuit and capture during successful feeding dives by fish-eating killer whales in coastal British Columbia, Canada. The significantly higher incidence and rate of echolocation prior to fish captures compared to afterward confirms its importance in prey detection and tracking. Extremely rapid click sequences (buzzes) were produced before or concurrent with captures of salmon at depths typically exceeding 50 m, and were likely used by killer whales for close-range prey targeting, as in other odontocetes. Distinctive crunching and tearing sounds indicative of prey handling behavior occurred at relatively shallow depths following fish captures, matching concurrent observations that whales surfaced with fish prior to consumption and often shared prey. Buzzes and prey-handling sounds are potentially useful acoustic signals for estimating foraging efficiency and determining if resident killer whales are meeting their energetic requirements

Identification guide to the heterobranch sea slugs (Mollusca: Gastropoda) from Bocas del Toro, Panama

The Bocas del Toro Archipelago is located off the Caribbean coast of Panama. Until now, only 19 species of heterobranch sea slugs have been formally reported from this area; this number constitutes a fraction of total diversity in the Caribbean region. The Bocas del Toro Archipelago is located off the Caribbean coast of Panama. Until now, only 19 species of heterobranch sea slugs have been formally reported from this area; this number constitutes a fraction of total diversity in the Caribbean region. This increase in known diversity strongly suggests that the distribution of species within the Caribbean is still poorly known and species ranges may need to be modified as more surveys are conducted.https://doi.org/10.1186/s41200-016-0048-

Sounds produced by Norwegian killer whales, Orcinus orca, during capture

To date very little is still known about the acoustic behavior of Norwegian killer whales, in particular that of individual whales. In this study a unique opportunity was presented to document the sounds produced by five captured killer whales in the Vestfjord area, northern Norway. Individuals produced 14 discrete and 7 compound calls. Two call types were used both by individuals 16178 and 23365 suggesting that they may belong to the same pod. Comparisons with calls documented in Strager (1993) showed that none of the call types used by the captured individuals were present. The lack of these calls in the available literature suggests that call variability within individuals is likely to be large. This short note adds to our knowledge of the vocal repertoire of this population and demonstrates the need for further studies to provide behavioural context to these sounds

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