Search Results for « Orca »

Killer whales (Orcinus orca) can produce 3 types of signals: clicks, whistles and vocalizations. This study focuses on Orca vocalizations from northern Vancouver Island (Hanson Island) where the NGO Orcalab developed a multi-hydrophone recording station to study Orcas. The acoustic station is composed of 5 hydrophones and extends over 50 km 2 of ocean. Since 2015 we are continuously streaming the hydrophone signals to our laboratory in Toulon, France, yielding nearly 50 TB of synchronous multichannel recordings. In previous work, we trained a Convolutional Neural Network (CNN) to detect Orca vocalizations, using transfer learning from a bird activity dataset. Here, for each detected vocalization, we estimate the pitch contour (fundamental frequency). Finally, we cluster vocalizations by features describing the pitch contour. While preliminary, our results demonstrate a possible route towards automatic Orca call type classification. Furthermore, they can be linked to the presence of particular Orca pods in the area according to the classification of their call types. A large-scale call type classification would allow new insights on phonotactics and ethoacoustics of endangered Orca populations in the face of increasing anthropic pressure.

Abstract Orca ( Orcinus orca ) is known for complex vocalisation. Their social structure consists of pods and clans sharing unique dialects due to geographic isolation. Sound type repertoires are fundamental for monitoring orca populations and are typically created visually and aurally. An orca pod occurring in the Ligurian Sea (Pelagos Sanctuary) in December 2019 provided a unique occasion for long-term recordings. The numerous data collected with the bottom recorder were analysed with a traditional human-driven inspection to create a repertoire of this pod and to compare it to catalogues from different orca populations (Icelandic and Antarctic) investigating its origins. Automatic signal detection and cross-correlation methods (R package warbleR) were used for the first time in orca studies. We found the Pearson cross-correlation method to be efficient for most pairwise calculations (> 85%) but with false positives. One sound type from our repertoire presented a high positive match (range 0.62–0.67) with one from the Icelandic catalogue, which was confirmed visually and aurally. Our first attempt to automatically classify orca sound types presented limitations due to background noise and sound complexity of orca communication. We show cross-correlation methods can be a powerful tool for sound type classification in combination with conventional methods.

Abstract We report the first video-documented case of orca ( Orcinus orca ) cooperative prey-handling and feeding behavior on a southern right whale (SRW, Eubalaena australis ) calf carcass, along with harassment events and whale responses, recorded in the Natural Protected Area El Doradillo in Península Valdés, Argentina. Drone footage and shore-based observations were conducted on September 5, 2025, revealing an orca group refloating and feeding on a sunken whale calf carcass. The orca group consisted of six identified individuals from the Península Valdés population. Drone footage (total recording time: 1 h 37 min) showed coordinated behavior among orcas, who alternated in holding, lifting, and releasing the carcass, suggesting cooperative handling. The orcas engaged in forty-six harassment events targeting southern right whales, especially mother–calf pairs. Defensive responses described as 360° turns and zigzag pattern were elicited more often when orcas approached from the latero-caudal angle with respect to SRW head. These results expand the knowledge on the behavioral ecology of this orca population and underscore the ecological significance of orca–right whale interactions in one of the most important SRW breeding grounds in the Southwestern Atlantic Ocean.

Abstract Orcas ( Orcinus orca ) are a charismatic species with multiple connections to local economies and culture in the Pacific Northwest. As such, emotions play a role in public perspectives and support for their conservation. This research presents the use of Natural Language Processing (NLP) emotion analysis to identify the basic emotions associated with written public responses to orca conservation proposals. We operationalized a multi‐dimensional emotion lexicon using Python 3 programing to extract the frequency and density of each basic emotion in over 17,000 public comments specific to orca conservation submitted to the Washington state governor's office. We found that respondents held a mixture of emotions. Trust was most often associated with the belief that urgent actions by state government could help orca populations, joy was most associated with statements reflecting how healthy orcas are icons for healthy ecosystems upon which all depend, and sadness was associated with statements lamenting the death of individual orcas and population extinction. These results can help conservation managers understand why people might support or reject conservation actions and move past conservation social science that has prioritized the emotional domain of fear. Moreover, NLP provides descriptive emotion analyses of big text datasets within specific conservation contexts that can be further explored through qualitative analyses.

Abstract The global distribution of Orcinus orca (orcas/killer whales) encompasses populations which differ from each other. Saddle patch shapes and sizes were compared for nearly 4,000 individuals, in 48 geographically or ecologically divided groups/populations/ecotypes (GP/E), in four Ocean Basins. Some Antarctic GP/E had five shapes, contrary to previous studies, which found only one shape in these Southern GP/E. Pacific Resident ecotypes had the highest variation in saddle patch shapes. Globally, the most common shape was the ‘Smooth’ category. Saddle patch sizes were measured using a ratio of the width of the saddle patch compared to the width of the dorsal fin base and averaged within each GP/E. The narrowest saddle patches were observed in New Zealand waters. The widest saddle patches were observed at the Crozet Islands and the Falkland Islands (Islas Malvinas). Globally, we found that the shape and size of saddle patches helped to define various GP/E, reinforcing earlier predictions that this pigmentation may be indicative of population divisions. Our findings may help with describing poorly defined or undescribed ecotypes. Such results may therefore aid assessments by management authorities/policy makers and provide levels of guidance in the creation of conservation or recovery plans.

Orcas ( Orcinus orca ) have a worldwide distribution and as apex predators feed on a wide variety of prey, including marine mammals, seabirds, sea turtles, cephalopods, teleost fish and elasmobranchs. Historically, there have been few observations of orca predation on large elasmobranch species nor are they commonly identified in the stomach contents of deceased orcas. In recent years there has been an increase in observational records of orca predation, such as on white sharks ( Carcharodon carcharias ) in South Africa, which could indicate that elasmobranchs serve a greater importance in their diet than previously considered. These events are often documented by members of the public due to the development and affordability of innovative cameras, including the use of the drones (unoccupied aerial vehicles). Here we describe new predator-prey interactions between orcas and large shark species in Cabo Pulmo National Park (CPNP), a small no-take marine protected area located in the Gulf of California. In this paper, we were able to successfully identify individuals from the described orca pods in the region; specifically, the same individuals hunting sharks over a period of nearly two years. We discuss the potential implications of these new ecological interactions, given the importance of tourism to sustain the management of CPNP, as cascading impacts have been documented elsewhere in light of orca predations on sharks.