Killer Whale (Orcinus orca) Opportunistic Predation Events on Whale Sharks (Rhincodon typus) in the Eastern Tropical Pacific

Marine Mammal Science, Journal Year: 2025, Volume and Issue: unknown

Published: March 12, 2025

Language: Английский

---

Movement behavior of a blue whale between the Galapagos Archipelago and the Frontal System off Baja California Peninsula

Marine Mammal Science, Journal Year: 2025, Volume and Issue: unknown

Published: Feb. 2, 2025

Abstract The movement behavior of blue whales in the Eastern Tropical Pacific (ETP) is not well understood, especially regarding migration Northeast (NEP) and Southeast (SEP) populations. This study presents tracking data from a satellite‐tagged whale recorded between Galapagos Islands Baja California Frontal System. A Bayesian state‐space model (BSAM) estimated whale's trajectory, hidden Markov (HMM) classified behavioral states. Environmental factors like sea surface temperature, chlorophyll‐a concentration, primary productivity, mesoscale eddies were analyzed to identify ecological drivers. displayed foraging areas with lower temperatures, higher elevated chlorophyll levels, movements influenced by cyclonic anticyclonic eddies. These findings improve understanding potential overlap NEP SEP populations key tropical regions. They suggest that Costa Rica Thermal Dome may serve as corridors,

Language: Английский

---

Integrated approaches for comprehensive cetacean research and conservation in the East China Sea

Marine Pollution Bulletin, Journal Year: 2024, Volume and Issue: 206, P. 116789 - 116789

Published: Aug. 1, 2024

Language: Английский

---

Behavioral responses of Bigg's and Southern Resident killer whales (Orcinus orca) to uncrewed aerial vehicle‐based breath sample collection

Marine Mammal Science, Journal Year: 2024, Volume and Issue: unknown

Published: Oct. 12, 2024

Uncrewed aerial vehicles (UAV), or drones, are one of many technological advances that enabling researchers to minimize anthropogenic disturbance when studying vulnerable species (Gonzalez et al., 2016). For cetaceans, UAVs have been used for photogrammetry (Christiansen 2020; Fearnbach 2019; Kotik 2023; Leslie 2022; Palacios & Cantor, Stewart 2022), photo-identification (Leslie Ryan and biological sampling (Centelleghe Horton 2019). Not only do provide an enhanced dorsal view on animals often elusive (Barreto 2021; Torres 2018), they also enable marine mammal collect data while keeping their boat at a greater distance than more traditional specimen collection technique would require (e.g., breath sample collected by telescoping pole from boat; Raverty 2017). Technology has created smaller quieter over time (Costa Pirotta 2017; Raudino 2019) making current day animal response difficult compare historical responses. While not accounting changes in time, studies show some mammals frequent pronounced responses UAVs, others not. example, no apparent behavioral were found bowhead whales (Balaena mysticetus; Koski 2015), humpback (Megaptera novaeangliae; Christiansen 2016), gray (Eschrichtius robustus; southern right (Eubalaena australis; 2020), Risso's dolphins (Grampus griseus; Hartman 2020). An important variable associated with UAV-induced response, where detected, is UAV altitude, which may reflect increased noise level visual detection lower altitudes. free-ranging common bottlenose (Tursiops truncatus) Belize showed flights altitudes between 11 30 m (Ramos 2018). Aubin al. (2023) observed St. Lawrence beluga (Delphinapterus leucas) evasive reactions flying (<23 m) higher ones and, based literature review, recommended altitude ≥30 cetaceans. Bottlenose (Delphinus delphis) off the coast Portugal exhibited changed direction was 5 m, but it (Castro 2021). Antillean manatees (Trichechus manatus manatus) displayed strong repeatedly followed Behavioral faster swimming, rolling, bucking, pectoral fin slaps) specific 3 blue (Balaenoptera musculus) Gulf California Guinea, Frederick Sound, Caribbean Sea, Stellwagen Bank single killer whale (Orcinus orca) Sound (Atkinson Specific shown observable including physalus, 13 m; Acevedo-Whitehouse 2010), (13 (0.5–3 2010; Costa 2017), (5 Domínguez-Sánchez (3 Centelleghe sperm (Physeter macrocephalus, This wide variation suggests addition flight pattern, differences exist (Raudino eye position extent upward field better detect UAVs. Other environmental demographic factors like day, angle sun shadows, season, temperament predator vs. prey species), animal's reproductive state could influence its (Domínguez-Sánchez 2018; Ramos Researchers flown relatively high (35–40 Southern Resident (SRKWs) mammal-eating transient/Bigg's (Durban 2015; 2023) without noting 2015). To whales, however, must be as low m. Breath evaluating health cetaceans hands-on examination possible (Acevedo-Whitehouse Hunt 2013) growing discipline human veterinary medicine (Zamuruyev The presence quantity inflammatory markers microorganisms likely similar concentrations blood perfuses lung alveoli known correlate various systemic local metabolic, endocrine, processes (Nollens Robeck Nollens, 2013). attempted number Atkinson 2021), aduncus Tursiops truncatus; 2019), (Sousa sahulensis; We evaluated close-proximity approaches capturing two sympatric distinct proposed ecotypes/species whales: endangered population fish-eating (SRKWs), Bigg's (de Bruyn 2013; Morin 2024). Video recorded boat-based camera analyzed determine if these modified sampling. hypothesized that, present, highest during phases focal follows. A (DJI MavicPro; Dà-Jiāng Innovations [DJI] Co. Ltd.) adding three-dimensional printed plastic platform attached reusable zip tie each front arms mounting 100 mm × 15 sterile petri dish (Figure 1). designed samples deployed Washington State waters Salish daylight hours September 2021 2022. All conducted calm weather conditions Beaufort sea <3 rain. Operations, launching retrieval UAV, well resolution videography, led professionally trained, NOAA-certified Pilot Charge 8-m Zodiac Hurricane 733 rigid hull inflatable following NOAA guidelines operating vessel around whales. Specifically, this included requirements operate minimum 15.2 descend 1.8 blow sampling, maintain 8,047 other Killer typically surface 3–4 times sequentially 20–30 s intervals longer hold dive approximately 2–3 min (SRKW) 5–6 (Bigg's). Accordingly, dives out observation range we match course speed remaining within 100–150 45° behind whale. When interest resurfaced, repositioned 20–50 follows consisted initially trailing 15–20 decrease 2.0–2.5 fly through plume surfaced exhale/inhale. allowed, 5–10 repeated samplings. Individual identified unique combination fin, patch, saddle patch morphology assign ecotypes/proposed (Bigg, 1987; Ford 2000; activities documented 4 K video imagery using Sony FDR AX53 (NTSC 60i) handheld camcorder 12.35-megapixel recorder integrated into payload. 1/2.3" CMOS sensor 28-mm lens 78.8° FOV. High videos processed separated ranging <1 47 s. Aerial defined four sequential phases: (1) presample, (2) collection, (3) interval, (4) postsample. "Collection" period near (2.0–2.5 attempting obtain sample. "Presample" before first attempt. "Intervals" periods "Postsample" after last Full-length recordings all divided postsample follows, above. Often, recordings. same approach assigned own follow phase binary score (1 = 0 response). Responses observed, just individual targeted Response scores independently three biologists proficient interpreting behavior (B.N., M.S., M.W.). Based behaviors prior published reports investigating cetacean Castro monitored suite predefined (Table In tier high-resolution biologists. Each full-length viewed full scoring understand sequence events context day. then reviewed visible change scored "response" whereas absence "no response." second review process, third biologist experienced so rarely footage there need initiate second-tier process. subset (n 100) 1,133 total both noted set randomly selected noted. sequences randomized such reviewer blind reviewers' scoring. least considered final count. fit Bayesian generalized linear mixed model (GLMM) assess difference probability SRKWs (presample, postsample) date, number, (or family of) random effects R package "brms." Priors specified standard normal fixed (ecotype phase). Model selection, diagnostics, convergence assessed balancing effective sizes, R-hat statistics, ESS, stability estimated posterior distribution parameter. ran chains 2,000 iterations adapt delta 0.98. Adapt defines target step acceptance Markov chain Monte Carlo (MCMC) procedure. Increasing default allowed make careful steps sampler thus eliminate divergent transitions against draws. statistical analyses performed (R Core Team, 2022). 35 seven 20 days effort Of flights, 12 23 90:26 (mm:ss) 265:31 (mm:ss), respectively. total, 131 1,002 2), 19 collected. During first-tier 1.6% (18 1,133) 1.1% 31 responses, agreed seeing five two, reviewer, who blinded 1 reviews, had previously seen showing degree agreement confirmed reviewers six SRKW (4.6%) (0.3%). GLMM weak evidence rate (difference ± SE −0.75 0.93, P[Bigg's < SRKW] 0.79; Figure 2). due different foraging ecology social structure (Baird Whitehead, 2000). routinely engage subsurface surface-active include rolling (Noren 2009; Tennessen, Holt, Hansen, Ward, possibly enhance chances detecting stimuli surface. Consequently, certain were, fact, caused UAV. There very interval 2.21 0.83, P[interval > collection] 0.99; 3). yet primarily responded It actual did elicit because approached usually dropped diving, overhead. If so, able further reduce rare eighth suggesting attempts follow. demonstrated can eastern North Pacific ecotypes minimal animals. those mild, reflecting awareness rather avoidance. No video, sensitive detection. future work concurrent use operated record group to, during, substantially larger sampled whales; 2023, persists briefly. estimates height ranges 2.7 4.7 (Horton requires closer successfully sufficient quantities vapor. Here demonstrate close-range Eight nine body maintaining swim direction, observe 4; n 5, ninth altered swimming avoidance detected Using permitted us keep research close (≤7.62 required collecting mounted (Raverty critical considering proximity alter biologically significant resting Giles, 2014; Hanson, Lusseau few study minor compared species. 4.3% (22/511) sudden dives. Comparably, (2021) deep speeds These types how respond vessels (Giles, 2014). Differences responsiveness related type species). Reeves (2008) classified either fight attacks Therefore, species' reactiveness predation external disturbances insight frequency UAV-breath worth comparing results methods (boat UAV) given chance conduct them individual. Our findings support utility valuable, lower-impact tool remotely recommend greatest still permits positioning exhaled plume. Also, pilots balance enough likelihood rapidly drop safely effectively. Future improve our understanding (anterior, posterior, lateral approaches) designs signature. thank T. Campana, E. Nilson, S. Teman logistical support. Funding provided NMFS, Rose Foundation, United Parks Resorts, National Fish Wildlife Foundation Marine Mammal Center. Additional funding processing, analysis, manuscript writing, page charges SeaDoc Society, program Karen C. Drayer Health Center, University California, Davis School Veterinary Medicine. San Diego Zoo Alliance Center Whale Research in-kind accordance Permits (USA: NMFS No. 21348) approved Northwest Fisheries Science Institutional Animal Care Use Committee. Candice Emmons, Jameal Samhouri, anonymous constructive peer-review manuscript. Catherine Feng-Yu Lo: Conceptualization; curation; formal analysis; investigation; methodology; project administration; resources; supervision; validation; visualization; writing – original draft; editing. Hendrik Nollens: acquisition; Brittany Data Maya Sears: Brad Hanson: Michael Weiss: James Sheppard: Charlie Welch: Robert Friel: Joseph Gaydos:

Language: Английский

---

Galapagos Pinnipeds, Challenges to Their Survival

IntechOpen eBooks, Journal Year: 2023, Volume and Issue: unknown

Published: Nov. 22, 2023

Pinnipeds endemic to the Galapagos archipelago are in endangered conservation status. The sea lion, Zalophus wollebaeki, and fur seal, Arctocephalus galapagoensis, have adapted an ecosystem with high environmental variability unpredictable marine productivity survive. In addition factors that pressure their populations, these species exposed anthropogenic influence, mainly rookeries on islands human settlements. It has been determined populations of pinnipeds different growth trends between regions archipelago, same region, island. 58% lion population is southeastern, largest rookery direct contact inhabitants. Various strategies proposed reduce negative impacts human–animal interaction, ensure population’s viability over time, species’ extinction risk.

Language: Английский

---

Insights into Blue Whale (Balaenoptera musculus L.) Population Movements in the Galapagos Archipelago and Southeast Pacific

Animals, Journal Year: 2024, Volume and Issue: 14(18), P. 2707 - 2707

Published: Sept. 18, 2024

The Galapagos Marine Reserve is vital for cetaceans, serving as both a stopover and residency site. However, blue whales, occasionally sighted here, exhibit poorly understood migratory behavior within the broader Eastern Tropical Pacific. This study, first to satellite tag whales in (16 tagged between 2021 2023), explored their relation environmental variables like chlorophyll-a concentration, sea surface temperature (SST), productivity. Key findings show strong correlation foraging behavior, high levels, productivity, lower SSTs, indicating preference food-rich areas. Additionally, there notable association with geomorphic features ridges, which potentially enhance food abundance. Most stayed near archipelago, higher concentrations observed around Isabela Island, increasingly frequented by tourist vessels, posing heightened ship strike risks. Some ventured into Ecuador's exclusive economic zone, while one migrated southward Peru. 2023 El Niño-Southern Oscillation event led SST primary production changes, likely impacting whale resource availability. Our study provides crucial insights habitat utilization, informing adaptive management strategies mitigate risks address altered migration routes due climate-driven shifts.

Language: Английский

---