Acoustic communication plays a fundamental role in coordinating social behaviors. From primates to elephants, social species use vocalizations to maintain contact, coordinate movement, and regulate social interactions. While the acoustic structure and contextual use of vocal signals have been widely studied, the temporal organization of vocal exchanges remains comparatively underexplored, despite increasing evidence that call timing carries meaningful social information and plays a central role in collective behavior. Here, we analyzed a dataset of semi-free African savanna elephants (Loxodonta africana) recorded in a standardized subgroup-separation context to elicit frequent contact rumbles. We applied three previously published methodological frameworks to the same dataset, each characterizing a different aspect of temporal coordination: quartile-based categories, bout criterion interval, and antiphonal probability analysis. We found that these statistical frameworks resulted in substantial variation in temporal boundaries and the classification of antiphonal signals, both within our dataset and relative to previous work. Quartile-based methods yielded shorter inter-call intervals, likely reflecting the high proportion of overlapping calls. Antiphonal probability analyses provided limited evidence for turn-taking across individuals. In contrast, bout criterion interval analysis revealed a comparatively longer temporal threshold, indicating that most vocalizations occurred within extended calling bouts. Overall, these findings demonstrate that methodological decisions strongly influence the identification and interpretation of temporal coordination, particularly antiphony, and can lead to differing conclusions about the presence and extent of coordinated vocal behavior. Consequently, given the limited number of existing studies on elephant vocal timing, early methodological choices may have a disproportionate impact on how temporal coordination is defined and detected, potentially shaping our understanding of coordinated vocal behavior in elephants.
Simone Antichi, Jorge Urbán R., Lorena Viloria-Gómora
Dolphin-watching and swim-with-dolphin tourism have expanded worldwide as part of the broader growth of marine mammal tourism. These activities can provide economic benefits to coastal communities, strengthen public engagement with marine wildlife, and promote conservation awareness. At the same time, repeated exposure to vessels and swimmers can affect cetacean behavior, habitat use, and, in some cases, population dynamics. Swim-with-orca tourism is a more recent and geographically restricted form of marine mammal tourism. Most available information comes from Northern Norway, where seasonal aggregations of orcas support a snorkeling industry. Existing studies suggest that underwater encounters between people and orcas do not necessarily trigger negative responses, but the long-term ecological consequences of repeated exposure remain uncertain. This review examines the current state of swim-with-dolphin and swim-with-orca tourism, with particular attention to their ecological and management implications. We then focus on Mexico, where marine mammal tourism is growing and where summer foraging aggregations of orcas in the Gulf of California have recently attracted increasing tourism interest and opportunistic swim-with-orca activities. As a case study, we describe the 2025–2026 swim-with-orca management plan for the Cerralvo Island region, Baja California Sur, Mexico. The plan establishes operational limits, spatial restrictions, and collaborative monitoring among authorities, researchers, and tourism operators. Although it shows some limits and its effectiveness will need to be evaluated over time, it provides an early example of a precautionary management approach to reduce human impacts while supporting more sustainable wildlife tourism.
Pilar N. Rodriguez, Samantha Cope King, Rebekah S. Lane, Julia E. O’Hern, Kathi George, William Keener, Brendan Tougher, Virgil Zetterlind, Ellen Hines
Globally, vessel strike is a major cause of mortality for large whales, especially where whales are concentrated near busy seaports. Whale-vessel strike risk assessments depend upon a comprehensive understanding of local vessel activity. However, vessel traffic data used for these assessments are typically acquired from Automatic Identification System (AIS) broadcasts by ships, and many vessels do not transmit AIS. Here, we investigated the crucial data gap in these assessments by comparing patterns of AIS and non-AIS vessel activity. To accomplish this, we used an innovative shore-based technology package (ProtectedSeas Marine Monitor, or M2) that repurposed an off-the-shelf marine radar, AIS receiver, and camera to track all vessel traffic. The M2 system positioned at the mouth of the Golden Gate Strait, the entrance to a busy seaport region, San Francisco Bay, CA, USA, provided data for one year of analysis, and we found that 81% of all tracks analyzed were from vessels not transmitting AIS. Non-AIS vessel operation movements were generally more variable, and seasonal trends in non-AIS vessel traffic differed from AIS traffic. The highest speeds reached by non-AIS vessels in clear weather remained consistent even when operating in reduced visibility conditions, such as in dense fog. Our study demonstrated that exclusively using AIS data to model vessel-strike risk can lead to significant underestimations of vessel traffic activity. At the same time, the method used here points to a solution, as this accessible technology can be readily deployed onshore to provide more comprehensive vessel data to produce robust strike risk assessments in coastal or geographically constrained whale habitat.
Kerkeslin R. MacDonald, Katherine L. Indeck, Kimberley T. A. Davies
Protecting marine mammals from anthropogenic threats, such as vessel strikes, requires accurate species occurrence data to ensure that management actions are justifiable. In Northwest Atlantic waters, several regions are seasonally monitored for baleen whales using near real-time (NRT) passive acoustic gliders. Two endangered species monitored, sei and blue whales, produce acoustically similar calls, complicating species discrimination in NRT. In this study, we sought to improve NRT blue whale monitoring in a region with irregular sei whale presence by implementing a new blue whale call library for automated detection and classification, and revised NRT analyst validation protocols. Acoustic detections from three deployments in 2025 were compared to six deployments from 2022-2024. NRT detections were reviewed audibly and visually to validate them post-deployment. The mean proportion of deployment days with detections misclassified as sei whale in NRT decreased from 3% to 0 in 2025, while true NRT blue whale detections increased by 89%. The new blue whale call library correctly classified blue whale calls in an average of 35% of blue whale ‘detected’ periods. Blue whale acoustic detections varied by season and location, with audible calls contributing to more detections than infrasonic calls. Overall, NRT misclassifications were reduced, and blue whale call discrimination improved, which is important for monitoring endangered species whose detection data inform conservation measures. These improvements are particularly relevant if either species is incorporated into future dynamic management strategies, such as the current NRT dynamic speed restriction program used to mitigate ship strike risk to North Atlantic right whales in the Gulf of St. Lawrence.
