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Sperm whales exhibit sexual dimorphism and sex-specific latitudinal segregation. Females and their young form social groups and are usually found in temperate and tropical latitudes, while males forage at higher latitudes. Historical whaling data and rare sightings of social groups in high latitude regions of the North Pacific, such as the Gulf of Alaska (GOA) and Bering Sea/Aleutian Islands (BSAI), suggest a more complex distribution than previously understood. Sperm whales are the most sighted and recorded cetacean in marine mammal surveys in these regions but capturing their demographic composition and habitat use has proven challenging. This study detects sperm whale presence using passive acoustic data from seven sites in the GOA and BSAI from 2010 to 2019. Differences in click characteristics between males and females (i.e., inter-click and inter-pulse interval) was used as a proxy for animal size/sex to derive time series of animal detections. Generalized additive models with generalized estimation equations demonstrate how spatiotemporal patterns differ between the sexes. Social groups were present at all recording sites with the largest relative proportion at two seamount sites in the GOA and an island site in the BSAI. We found that the seasonal patterns of presence varied for the sexes and between the sites. Male presence was highest in the summer and lowest in the winter, conversely, social group peak presence was in the winter for the BSAI and in the spring for the GOA region, with the lowest presence in the summer months. This study demonstrates that social groups are not restricted to lower latitudes and capture their present-day habitat use in the North Pacific. It highlights that sperm whale distribution is more complex than accounted for in management protocol and underscores the need for improved understanding of sperm whale demographic composition to better understand the impacts of increasing anthropogenic threats, particularly climate change.

Renowned marine mammal scientist Roger Payne, who passed away in 2023 at the age of 88, is best known for his work on humpback whale songs, which helped change public perception of whales. His research on live whales at sea and his recordings of humpback songs played a significant role in the environmental conservation movement of the early 1970s. Payne's contributions extended beyond whales, as he conducted groundbreaking research on other species and was known for his ability to merge science, art, and music. The text also highlights the experiences and mentorship of Roger and Katy Payne, emphasizing their generosity, wisdom, and dedication to conservation. The authors express gratitude for the opportunities and knowledge gained through their association with the Paynes. [Extracted from the article]

Background: In ecosystems influenced by strong seasonal variation in insolation, the fitness of diverse taxa depends on seasonal movements to track resources along latitudinal or elevational gradients. Deep pelagic ecosystems, where sunlight is extremely limited, represent Earth's largest habitable space and yet ecosystem phenology and effective animal movement strategies in these systems are little understood. Sperm whales (Physeter macrocephalus) provide a valuable acoustic window into this world: the echolocation clicks they produce while foraging in the deep sea are the loudest known biological sounds on Earth and convey detailed information about their behavior. Methods: We analyze seven years of continuous passive acoustic observations from the Central California Current System, using automated methods to identify both presence and demographic information from sperm whale echolocation clicks. By integrating empirical results with individual-level movement simulations, we test hypotheses about the movement strategies underlying sperm whales' long-distance movements in the Northeast Pacific. Results: We detect foraging sperm whales of all demographic groups year-round in the Central California Current System, but also identify significant seasonality in frequency of presence. Among several previously hypothesized movement strategies for this population, empirical acoustic observations most closely match simulated results from a population undertaking a "seasonal resource-tracking migration", in which individuals move to track moderate seasonal-latitudinal variation in resource availability. Discussion: Our findings provide evidence for seasonal movements in this cryptic top predator of the deep sea. We posit that these seasonal movements are likely driven by tracking of deep-sea resources, based on several lines of evidence: (1) seasonal-latitudinal patterns in foraging sperm whale detection across the Northeast Pacific; (2) lack of demographic variation in seasonality of presence; and (3) the match between simulations of seasonal resource-tracking migration and empirical results. We show that sperm whales likely track oceanographic seasonality in a manner similar to many surface ocean predators, but with dampened seasonal-latitudinal movement patterns. These findings shed light on the drivers of sperm whales' long-distance movements and the shrouded phenology of the deep-sea ecosystems in which they forage. [ABSTRACT FROM AUTHOR]

Male sperm whales (Physeter macrocephalus) are known to interact with and depredate from commercial longline fishing vessels targeting sablefish (Anoplopoma fimbria) in the Gulf of Alaska (GOA). This study aims to better understand their movement patterns and diving behavior in this region, and in relation to depredation behavior. Between 2007 and 2016 a total of 33 satellite tags were deployed on sperm whales interacting with fishing vessels in the eastern GOA. A subset of these tags also collected dive characteristics. We used state space models to interpolate hourly positions from tags and estimate behavioral state from 29 usable tag records, 14 of which had associated dive information. Whales exhibited slower horizontal movement (1.4 km/hr) within GOA waters compared to south of the GOA (5.5 km/hr), indicating tagged whales sped up when they left the region. Behavioral states indicated primarily foraging behavior (82% of locations) in the GOA and primarily transiting behavior (74% of locations) when whales left the GOA. Dive data showed average (± Standard Deviation) maximum dive depths of 396 m (± 166), and dive durations of 32 min (± 9). Generalized additive models indicated that dives were significantly deeper and longer during the daytime than dawn, dusk, or nighttime, and dives were significantly deeper and shorter during quarter moons, when tidal currents are weakest. Maximum dive depth decreased in areas of higher sablefish CPUE, suggesting a potential link between the sablefish fishery and depredation behavior. As seafloor depth increased, up to 800 m, dives became deeper, indicating that whales were likely targeting both bathypelagic and mesopelagic prey. This highlights the importance of the GOA continental slope as a foraging ground for male sperm whales. This enhanced understanding of sperm whale foraging ecology informs management and conservation efforts in high latitude foraging grounds. [ABSTRACT FROM AUTHOR]

Sperm whales spatially segregate by sex and social behavior as they mature. In the North Atlantic, male whales move to higher latitudes as far as Svalbard at 80° N, while females and young whales typically remain around lower latitudes below 40–45° N. The Azores, Madeira, and the Canary Islands constitute important nursery grounds for female and young sperm whales. Irish waters represent a midpoint for this species' spatial segregation in the Northeast Atlantic, where the species occurs along the submarine canyon systems to the west of the country. Historically, just male whales were thought to be found in this region between 51 and 55° N, but one adult female was caught by commercial whalers in 1910, and a 5.49 m calf was found stranded in 1916. Between 1995 and 2023, 10 female sperm whales have been stranded around the coast of Ireland. Eight of these whales have been stranded since 2013, and there has been at least one stranding per year between 2019 and 2023. Four of these strandings have occurred in Donegal in the northwest of Ireland, indicating the presence of female whales along the continental shelf off this region. Two females were stranded within a day of each other and were found in similar states of decomposition in February 2022, indicating that they may have been part of the same group rather than being lone vagrant individuals. Sperm whale calves and juveniles were also sighted in Irish waters in 2001, 2004, and 2010 in the Rockall Trough, along the Porcupine Bank and Goban Spur, where between 1 and 3 individuals were observed on four occasions while one calf live stranded in 2004. These records indicate a historical presence of female and young sperm whales in this region but that an apparent increase in occurrence has taken place over the past decade. [ABSTRACT FROM AUTHOR]

Sperm whales (Physeter macrocephalus) have been studied for decades, but the development of their clicks during the animal growth is not yet well known. The click they emit during socialization and echolocation contains information about the length of their acoustic organs and, therefore the length of the body through the interpulse interval (IPI). This paper provides the first IPI/age relationship for juvenile male and female sperm whales (Physeter macrocephalus) based on field recordings of individuals whose age is largely known. Across 9 years, audiovisual recordings of a Mauritian sperm whale social unit were carried out. Adult female and juvenile sperm whales were identified and aged. The dataset made from those recordings is publicly available. The interpulse interval was measured for individuals whose ages ranged from 7 days to around 38 years. The growth of the acoustic organ of juveniles showed an early inter-individual variability as well as sexual dimorphism. Usual growth models were also fitted, predicting a mean I P I ∞ of 3.5 ms for adults and a physical maturity reached at around 30 years old. The use of passive acoustic monitoring (PAM) is one of the main tools used to study sperm whales. This IPI-age relationship may aid demographic studies on sperm whales by enabling PAM to assess the ages of recorded sperm whales. [ABSTRACT FROM AUTHOR]

Codas are vocalisations produced by sperm whales (Physeter macrocephalus) in social settings consisting of a short series of clicks with a stereotyped time pattern and are identified as cultural markers for different sperm whale populations across the globe. The current study analysed data from the OνDE acoustic station, part of the NEMO-SN1, between 2005 and 2006 at 2000 m depth off the coasts of Catania, Italy, to monitor the soundscape. Codas were classified using parsimonious mixtures of multivariate contaminated normal distributions based on their absolute inter-click interval and number of clicks per coda. The models found 3 clusters for three-click codas, 4 for four-click patterns, and 1 for the five-click pattern, with 8 clusters divided into three families. Codas of the '3 + 1' and '2 + 1' families were the most represented for all years and months, and the summer months had the highest number of detections. This study integrates well within the current knowledge of the coda repertoire of Mediterranean sperm whales and offers a new study location placed in the Ionian Sea, a strategic point where individuals could pass from the Western to the Eastern basin. [ABSTRACT FROM AUTHOR]

The use of Pop‐up Satellite Archival Tags (PSATs) has provided considerable new information about the behaviour of migrating (silver) eels (Anguilla spp.) at sea, with 9 of 19 recognised species or subspecies tagged to date. However, such studies often reported premature tag detachment and relatively high rates of predation. Since 2000, several PSAT‐tagged New Zealand longfin eels, Anguilla dieffenbachii, were released to understand migratory behaviour and location of potential spawning grounds. Of 20 PSAT‐tagged eels released in 2019, all tags detached prematurely, but 7 (58%) were likely eaten or injured by predators 1–81 days after release. Two eels were probably eaten by sperm whales, whereas other tagged eels were likely eaten by lamniform and non‐lamniform sharks, and southern bluefin tuna. Because of the high rate of predation, we recommend that future releases should be from smaller catchments or offshore. [ABSTRACT FROM AUTHOR]

This article discusses observations of killer whale attacks on sei and fin whales in the Magellanic Sub-Antarctic Waters of Chile. The attacks occurred between March 2020 and April 2021 and resulted in the death of the whales. The researchers were able to identify one female killer whale involved in three of the attacks, which is relatively rare. The study emphasizes the need for further research on the trophic ecology and dietary plasticity of killer whales in the area. Additionally, a collection of articles and studies on killer whale behavior, diet, and interactions with other marine species is provided. [Extracted from the article]

Humpback whales in Bermuda have been observed engaging in a unique behavior of expanding their oral pouches and rubbing them against the seafloor. This behavior is believed to be a method of skin maintenance in areas where barnacles and whale lice congregate. The whales were observed swimming together, often in pairs, and descending into sand holes to rub their expanded pouches against the bottom. This behavior is different from feeding and may serve as a way for the whales to exfoliate and clean hard-to-reach areas of their bodies. Further research is needed to fully understand this behavior. [Extracted from the article]

This article discusses a study on estimating the population size of Eastern Caribbean sperm whales for conservation purposes. The researchers conducted surveys in the Lesser Antilles region and used photo identification and acoustic data to estimate the population size. They found that the population is structured at a small spatial scale and that previous data from Dominica is biased and does not represent the entire population. The study provides more accurate population estimates for sperm whales in the region and emphasizes the need to consider different vocal clans separately in conservation efforts. The study also highlights the limitations of the methods used and the importance of cultural diversity in conservation. [Extracted from the article]

Large whale entanglements are considered a significant threat to populations on a global scale. In the Mexican Pacific and Baja California Peninsula (1996–2021) a total of 218 confirmed entangled whales, from which 99 (45.4%) whales were fully released (66 by the Mexican Whale Disentanglement Network, known as RABEN). Five whale species were reported in confirmed entanglements: humpback (Megaptera novaeangliae, n = 187), gray (Eschrichtius robustus, n = 19), sperm (Physeter macrocephalus, n = 5), Bryde's (Balaenoptera edeni, n = 4), and fin (Balaenoptera physalus, n = 3). Eight types of fishing gear were identified out of 209 different gear sets; gill nets were the most common (n = 101, 48.3%), followed by pots (n = 49, 23.4%). Entanglements were reported in sixteen locations, and Banderas Bay had the most entanglement reports (n = 81, 32.8%). Several entanglements were tracked across multiple locations (n = 7), involving two teams with the most successful releases (n = 5), proving the efficiency of the RABEN entanglement response network. This information can be used to better understand entanglement impacts on large whales in the North Pacific and particularly in Mexico, to work towards mitigation of a problem that affects both whales and fishermen. [ABSTRACT FROM AUTHOR]

We studied δ13C, δ15N and δ18O values, and total mercury (THg) concentrations in muscle samples from deep-sea predators – five beaked whale species and sperm whales – stranded along the coast of Hokkaido, in the north of Japan in 2010 and 2019. The δ13C, δ15N and δ18O values, THg concentrations, and body length (BL) of Stejneger's beaked whales were similar to those of Hubbs' beaked whales, which belong to the same genus. In contrast, δ13C values, THg concentrations, and BL of Sato's beaked whales were markedly different from those of Baird's beaked whales, which belong to the same genus. Stejneger's and Hubbs' beaked whales living around Hokkaido may compete in their ecological niches, whereas Sato's and Baird's beaked whales may segregate their ecological niches. Although Cuvier's beaked whales and sperm whales belong to different genera and their BLs were significantly different, their δ13C and δ15N values were similar, probably because they can dive and stay in deeper waters than other beaked whale species. The δ13C values in combined samples from all whales increased with increasing BL, probably owing to the larger whale species' dietary preference for squid. The δ13C values in combined samples from all whales were positively correlated with THg concentrations, whereas the δ15N values in the combined samples were negatively correlated. The δ18O values in combined samples from most whales tended to be positively correlated with THg concentrations. These correlations may be explained by a higher THg load from deep-sea feeding than from pelagic feeding and by a feeding shift towards lower trophic levels. [ABSTRACT FROM AUTHOR]

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An underwater acoustic recorder was moored off Heard Island from September 2017 through March 2018 to listen for marine mammals. Analysis of data was initially conducted by visual inspection of long-term spectral averages to reveal sounds from sperm whales, Antarctic and pygmy blue whales, fin whales, minke whales, odontocete whistles, and noise from nearby ships. Automated detection of sperm whale clicks revealed they were seldom detected from September through January (n = 35 h) but were detected nearly every day of February and March (n = 684 h). Additional analysis of these detections revealed further diel and demographic patterns. [ABSTRACT FROM AUTHOR]

Diterpenoids are an important class of secondary metabolites in nature with diverse applications such as pharmaceuticals, flavors and fragrances. Sclareol, a plant-derived diterpene alcohol from Salvia sclarea, is most commonly used as the starting material for the production of hemisynthetic Ambrox, a valuable substitute for ambergris from sperm whales used in perfumery. Here, we engineered the oleaginous yeast Yarrowia lipolytica as a chassis for sclareol overproduction. We constructed a de novo sclareol biosynthetic pathway by screening and engineering heterologous LPP synthase (Lpps) and sclareol synthase (Scs). By constructing a two-layer geranylgeranyl diphosphate (GGPP) accumulation pathway and scaffold-free multienzyme complexes, the metabolic flux was redirected toward sclareol synthesis, enabling significantly improved production of sclareol and reduced levels of by-products. The engineered strain was capable of producing 12.9 g L-1 of sclareol in a 5 L bioreactor, with this being the highest titer achieved to date. To the best of our knowledge, this is the first report of sclareol biosynthesis in Y. lipolytica, and this chassis strain may offer a groundbreaking foundation for the sustainable, large-scale fermentation of diterpenoids. [ABSTRACT FROM AUTHOR]

This article provides an update on the cetacean species list in Raja Ampat, Indonesia, with new sightings of Omura's whale and melon-headed whales. The study was conducted through boat-based surveys and opportunistic observations using drones and ferries. The researchers encountered five species, including Omura's whales and melon-headed whales. These findings contribute to filling information gaps and updating the cetacean species list in Raja Ampat. The document also provides a list of references related to marine biodiversity, marine mammals, and conservation efforts in Indonesia, which can be valuable resources for library patrons conducting research on these subjects. [Extracted from the article]

Research in the western Mediterranean has shown that sperm (Physeter macrocephalus) and Cuvier's beaked whales (Ziphius cavirostris) are present as small, globally distinct populations that face numerous threats.The eastern Mediterranean is not well studied, and few surveys have investigated the composition of cetacean communities. In this study, visual‐acoustic surveys were conducted off the coast of Israel during April–May 2022 to characterize the cetacean community.Sperm whales (three encounters), Cuvier's beaked whales (one encounter), bottlenose dolphins (one encounter (Tursiops truncatus)) and unidentified delphinids (17 encounters) were acoustically detected.Sperm whales were foraging ~10 km off Haifa, at 370–1220 m deep and social vocalizations (codas) corresponded to the Mediterranean dialect. One immature male that was photographed is known from 12 previous encounters in the Ligurian Sea, indicating a west–east movement of approximately 2800 km.Automated passive acoustic monitoring of narrow, relatively shallow areas such as the Sicily Channel could provide an opportunity to reduce mortality of individuals making long‐distance movements within Mediterranean basins. Israeli waters provide habitat for cetaceans, with two threatened subpopulations—sperm and Cuvier's beaked whales—that are negatively impacted by anthropogenic activities, including those that introduce underwater noise. More data are needed on densities of these deep‐water species, and an evaluation of the threats faced in the wider Levantine basin. [ABSTRACT FROM AUTHOR]

Abstract Sperm whales spatially segregate by sex and social behavior as they mature. In the North Atlantic, male whales move to higher latitudes as far as Svalbard at 80° N, while females and young whales typically remain around lower latitudes below 40–45° N. The Azores, Madeira, and the Canary Islands constitute important nursery grounds for female and young sperm whales. Irish waters represent a midpoint for this species’ spatial segregation in the Northeast Atlantic, where the species occurs along the submarine canyon systems to the west of the country. Historically, just male whales were thought to be found in this region between 51 and 55° N, but one adult female was caught by commercial whalers in 1910, and a 5.49 m calf was found stranded in 1916. Between 1995 and 2023, 10 female sperm whales have been stranded around the coast of Ireland. Eight of these whales have been stranded since 2013, and there has been at least one stranding per year between 2019 and 2023. Four of these strandings have occurred in Donegal in the northwest of Ireland, indicating the presence of female whales along the continental shelf off this region. Two females were stranded within a day of each other and were found in similar states of decomposition in February 2022, indicating that they may have been part of the same group rather than being lone vagrant individuals. Sperm whale calves and juveniles were also sighted in Irish waters in 2001, 2004, and 2010 in the Rockall Trough, along the Porcupine Bank and Goban Spur, where between 1 and 3 individuals were observed on four occasions while one calf live stranded in 2004. These records indicate a historical presence of female and young sperm whales in this region but that an apparent increase in occurrence has taken place over the past decade.

Male sperm whales (Physeter macrocephalus) are known to interact with and depredate from commercial longline fishing vessels targeting sablefish (Anoplopoma fimbria) in the Gulf of Alaska (GOA). This study aims to better understand their movement patterns and diving behavior in this region, and in relation to depredation behavior. Between 2007 and 2016 a total of 33 satellite tags were deployed on sperm whales interacting with fishing vessels in the eastern GOA. A subset of these tags also collected dive characteristics. We used state space models to interpolate hourly positions from tags and estimate behavioral state from 29 usable tag records, 14 of which had associated dive information. Whales exhibited slower horizontal movement (1.4 km/hr) within GOA waters compared to south of the GOA (5.5 km/hr), indicating tagged whales sped up when they left the region. Behavioral states indicated primarily foraging behavior (82% of locations) in the GOA and primarily transiting behavior (74% of locations) when whales left the GOA. Dive data showed average ( ± Standard Deviation) maximum dive depths of 396 m ( ± 166), and dive durations of 32 min (± 9). Generalized additive models indicated that dives were significantly deeper and longer during the daytime than dawn, dusk, or nighttime, and dives were significantly deeper and shorter during quarter moons, when tidal currents are weakest. Maximum dive depth decreased in areas of higher sablefish CPUE, suggesting a potential link between the sablefish fishery and depredation behavior. As seafloor depth increased, up to 800 m, dives became deeper, indicating that whales were likely targeting both bathypelagic and mesopelagic prey. This highlights the importance of the GOA continental slope as a foraging ground for male sperm whales. This enhanced understanding of sperm whale foraging ecology informs management and conservation efforts in high latitude foraging grounds.

Background: Ambergris is a coprolith produced by some sperm whales (∼1 %). It has been hypothesised that the metals in ambergris derive from the haemolymph of squid in the whale diet (mainly copper). However, few data exist.We report analysis of 10 trace metals in each of 50 ambergris samples by inductively coupled plasma-mass spectrometry. Main Findings: Acid digests of the samples contained ∼5 to >6880 µg g−1 air-dried weight total metals; mainly of iron (present in ∼90 % of samples, 38), copper (∼95 % of samples, 40), zinc (93 % of samples, 39) and cadmium (∼95 % of samples, 40). Conclusions: We suggest the variable and sometimes high concentrations of iron may reflect traces of haemoglobin or myoglobin from the whales. There may be other sources.The other major metals (Zn, Cu, Cd) are those also reported in several squid species. The distributions are unlike those of squid haemolymph alone, reportedly dominated by copper, or those of the sperm whale (e.g., skin), dominated by zinc.

The article is a review of a book titled "Sex in Cetaceans: Morphology, Behavior, and the Evolution of Sexual Strategies." The book consists of 24 chapters written by different authors, providing an overview of the reproductive strategies and behaviors of cetaceans. It includes new research on the reproduction of specific species of toothed and baleen whales. The chapters cover topics such as genetic tools for parentage analysis, sexual anatomy, reproductive strategies, nonconceptive sexual behavior, infanticide, and drone perspectives on mating behavior. The book also discusses the impact of human activities on cetacean reproductive health. Overall, the book is recommended for those interested in learning more about reproduction and mating systems in aquatic-living mammals. [Extracted from the article]

On the 21st of May 2023, a dead adult male sperm whale (Physeter macrocephalus) of 13 m in length and estimated weight of around 18,000 kg was reportedly stranded at Playa Los Nogales, La Palma, Canary Islands, Spain. A necropsy was performed 48hpm. A 50 cm diameter and 9.5 kg coprolite was found obstructing the caudal colon-rectal lumen. Necro-hemorrhagic lesions were found in heart muscles and three different bacteria of intestinal origin were isolated and identified (Edwarsiella tarda, Hathewaya limosa and Clostridium perfringens). It is reported a lethal septicemia of intestinal origin associated with ambergris coprolite as cause of death in this sperm whale. [ABSTRACT FROM AUTHOR]

Passive acoustic monitoring (PAM) is an optimal method for detecting and monitoring cetaceans as they frequently produce sound while underwater. Cue counting, counting acoustic cues of deep-diving cetaceans instead of animals, is an alternative method for density estimation, but requires an average cue production rate to convert cue density to animal density. Limited information about click rates exists for sperm whales in the central North Pacific Ocean. In the absence of acoustic tag data, we used towed hydrophone array data to calculate the first sperm whale click rates from this region and examined their variability based on click type, location, distance of whales from the array, and group size estimated by visual observers. Our findings show click type to be the most important variable, with groups that include codas yielding the highest click rates. We also found a positive relationship between group size and click detection rates that may be useful for acoustic predictions of group size in future studies. Echolocation clicks detected using PAM methods are often the only indicator of deep-diving cetacean presence. Understanding the factors affecting their click rates provides important information for acoustic density estimation. [ABSTRACT FROM AUTHOR]

The Cold Pool is a subsurface layer with water temperatures below 2 °C that is formed in the eastern Bering Sea. This oceanographic feature of relatively cooler bottom temperature impacts zooplankton and forage fish dynamics, driving different energetic pathways dependent upon Bering Sea climatic regime. Odontocetes echolocate to find prey, so tracking foraging vocalizations acoustically provides information to understand the implications of climate change on Cold Pool variability influencing regional food web processes. Vocal foraging dynamics of ice-associated and seasonally migrant marine mammal species suggest that sperm whales spend more time searching for prey in warm years when the Cold Pool is reduced but are more successful at capturing prey during cold years when the Cold Pool is stronger. Beluga whale foraging vocal activity was relatively consistent across climate regimes but peaked during the warm regime. Killer whale foraging vocal activity peaked in both warm and cold regimes with indicators of different ecotypes exploiting changing prey conditions across climate regimes. Foraging activity of odontocete apex predators may serve as a sentinel indicator of future ecosystem change related to prey availability that is linked to a diminishing Cold Pool as water temperatures rise and seasonal sea ice decreases due to climate change. [ABSTRACT FROM AUTHOR]

This article reports the first direct observation of a successful southern right whale birth in South African coastal waters. Southern right whale females typically migrate to coastal areas in South Africa to give birth and nurse their young. The calving season extends from late June to late October, with a peak in August. Despite long-term research efforts, very little is known about the birthing event in southern right whales. The article describes the observation of a lone southern right whale performing unique behaviors, followed by the birth of a calf. The mother did not assist the calf immediately after birth, which is consistent with behavior observed in other successful cetacean births. The article highlights the value of opportunistic data and the need for further research to improve our understanding of cetacean behavior and ecology. [Extracted from the article]

Despite the well-documented, broad global distribution of sperm whales (Physeter macrocephalus), their distributional patterns remain poorly known in Arctic regions, where year-round monitoring is challenging. Adult male sperm whales are known to migrate seasonally between nutrient-rich high latitude waters and low latitude breeding grounds. However, knowledge is limited regarding fine-scale distribution and seasonal presence at high latitudes. To investigate the acoustic occurrence of this vocally active species in the High Arctic of the Northeast Atlantic, this study combined automated and manual click detection methods to analyze passive acoustic data collected at eight locations around the Svalbard Archipelago, Norway, between 2012 and 2021. The results revealed the presence of sperm whales at six recording sites and demonstrated sperm whale "hotspots" in ice-free areas in eastern Fram Strait along the shelf break and close to the west coast of Spitsbergen from May–January, with some variation between years and locations. Although acoustic presence decreased with increasing latitude, even the northern-most location (81° N) recorded sperm whale vocal activity between August and January. This study provides a baseline for sperm whale acoustic presence in the High Arctic, which will be essential in the context of detecting future changes and also for predicting future distribution patterns in the rapidly changing Arctic marine environment. [ABSTRACT FROM AUTHOR]

Determining how animals allocate energy, and how external factors influence this allocation, is crucial to understand species' life history requirements and response to disturbance. This response is driven in part by individuals' energy balance, prey characteristics, foraging behaviour and energy required for essential functions. We developed a bioenergetic model to estimate minimum foraging success rate (FSR), that is, the lowest possible prey capture rate for individuals to obtain the minimum energy intake needed to meet daily metabolic requirements, for female sperm whale (Physeter macrocephalus). The model was based on whales' theoretical energetic requirements using foraging and prey characteristics from animal‐borne tags and stomach contents, respectively. We used this model to simulate two prey structure change scenarios: (1) decrease in mean prey size, thus lower prey energy content and (2) decrease in prey size variability, reducing the variability in prey energy content. We estimate the whales need minimum of ~14% FSR to meet their energetic requirements, and energy intake is more sensitive to energy content changes than a decrease in energy variability. To estimate vulnerability to prey structure changes, we evaluated the compensation level required to meet bioenergetic demands. Considering a minimum 14% FSR, whales would need to increase energy intake by 21% (5–35%) and 49% (27–67%) to compensate for a 15% and 30% decrease in energy content, respectively. For a 30% and 50% decrease in energy variability, whales would need to increase energy intake by 13% (0–23%) and 24% (10–35%) to meet energetic demands, respectively. Our model demonstrates how foraging and prey characteristics can be used to estimate impact of changing prey structure in top predator energetics, which can help inform bottom‐up effects on marine ecosystems. We showed the importance of considering different FSR in bioenergetics models, as it can have decisive implications on estimates of energy acquired and affect the conclusions about top predator's vulnerability to possible environmental fluctuations. [ABSTRACT FROM AUTHOR]

Simple Summary: Monitoring microplastics (MPs) in cetaceans is challenging due to difficulties in obtaining samples, especially for endangered species. In this study, we characterized MPs ingested in nine individuals of four cetacean species stranded along the western coast of the Taiwan Strait including not only small coastal dolphins but also large pelagic and deep-diving cetaceans. A total intestine length of 123.2 m was analyzed, and the color, shape, size, and polymer types of MPs were then identified. The mean abundance of MPs was 86.44 ± 12.22 items individual−1, which was slightly higher compared with the same species from other waters worldwide. Moreover, a strong significant relationship between MPs abundance and intestine contents mass was identified. Transparent, fibrous MPs made from PET and PP were found to be predominant in the present study, indicating that the primary MPs source is from municipal and industrial sewage from clothing production and industry as well as from fisheries and aquaculture. Our study provides more information about the MPs pollution of endangered species in the western Taiwan Strait. It highlights the further risk assessment of MPs consumption in these threatened species. Microplastics (MPs) pollution is of global concern, which poses serious threats to various marine organisms, including many threatened apex predators. In this study, MPs were investigated from nine cetaceans of four different species, comprising one common dolphin (Delphinus delphis), two pygmy sperm whales (Kogia breviceps), one ginkgo-toothed beaked whale (Mesoplodon ginkgodens), and five Indo-Pacific humpback dolphins (Sousa chinensis) stranded along the western coast of the Taiwan Strait from the East China Sea based on Fourier transform infrared (FTIR) spectroscopy analysis. Mean abundances of 778 identified MPs items were 86.44 ± 12.22 items individual−1 and 0.43 ± 0.19 items g−1 wet weight of intestine contents, which were found predominantly to be transparent, fiber-shaped polyethylene terephthalate (PET) items usually between 0.5 and 5 mm. The abundance of MPs was found at a slightly higher level and significantly correlated with intestine contents mass (p = 0.0004*). The MPs source was mainly likely from synthetic fibers-laden sewage discharged from intense textile industries. Our report represents the first study of MPs in pelagic and deep-diving cetaceans in China, which not only adds baseline data on MPs for cetaceans in Asian waters but also highlights the further risk assessment of MPs consumption in these threatened species. [ABSTRACT FROM AUTHOR]

Acoustic surveys for sperm whales (Physeter macrocephalus) were conducted in the Mediterranean Sea in summer 2018 as part of the vessel-based component of the ACCOBAMS Survey Initiative (ASI). Equal-spaced zigzag transects provided uniform coverage of key sperm whale habitats and were surveyed using a towed hydrophone array deployed from a research vessel at speeds of 5-8 knots. A total of 14,039 kmof tracklines were surveyed in the western basin, Hellenic Trench and Libyan waters, with an acoustic coverage of 10% realised for sperm whales. During these surveys, 254 individual spermwhales were detected on the trackline, with an additional 66 individuals off-track. Sperm whales were only seen ten times ontrack, with an additional 16 off-track sightings. Estimates of slant range to echolocating whales were used to derive density estimates through both design- and model-based distance sampling methodologies. An acoustic availability of 0.912 (sd = 0.036) was derived from via published models. When correcting for availability bias, a design-based abundance estimates of 2,673 individuals (95% CI 1,739-4,105; CV = 0.21) was derived for the surveyed blocks, which incorporated most known sperm whale habitat in the Mediterranean Sea. The equivalent model-based estimate was 2,825 whales (2,053-3,888; CV = 0.16). Over 97% of detected whales were in the western basin, with highest densities in the Algerian and Liguro-Provencal Basins between Algeria and Spain/France. In the eastern basin, detections were sparse and concentrated along the Hellenic Trench. A density surface modelling (DSM) exercise identified location and benthic aspect as being the most instructive covariates for predicting whale abundance. Distance sampling results were used in a power analysis to quantify the survey effort required to identify population trends. In the most extreme scenario modelled (10% per annum decline with decennial surveys), the population could have dropped by 90% before the decline was identified with high statistical power. Increasing the regularity of surveys would allow population trends to be detected more expediently. Mediterranean sperm whales are listed as Endangered on the IUCN's Red List and the need for urgent conservation measures to reduce injury and mortality remains paramount for this unique sub-population. [ABSTRACT FROM AUTHOR]

Context: Strandings are an important source of information for estimating marine mammal biodiversity, particularly in data-sparse ocean basins such as Oceania. Aims: Here, we report on knowledge acquired from 218 stranding events recorded in the waters of New Caledonia (1877–2022). Methods: We investigated spatio-temporal distribution, stable isotope signatures, trace element concentrations, biometry measurements, genetic diversity, and diet, for the four most commonly stranded taxa (dugongs, 35% of events; sperm whales, 19%; Delphinidae, 18%; pygmy and dwarf sperm whales, 14%). Key results: Beginning in 1991, reports of stranding events increased (183 events, 322 individuals, 20 species from seven families: Dugongidae, Physeteridae, Delphinidae, Kogiidae, Ziphiidae, Balaenopteridae, Otariidae), with hotspots identified on the west coast (Bourail, Ouano, Nouméa) and in Prony Bay. Causes of death were not determined in 84% of stranding events, but were identified in the majority of expert-led necropsies (24 of 29 individuals from 10 species). Yet, valuable information regarding the impact of anthropogenic activities was gathered for some species of concern, such as the endangered dugong (28% human-caused). Since 2016, training and outreach have been provided to rangers, veterinarians, and various public safety officers to support their engagement in the scientific monitoring of marine mammal strandings. A website (www.rescue.ird.nc) was developed to facilitate standardised data collection and storage, and to provide public access to stranding records. Conclusion: Although the number of individuals reported here remains modest, this study provides new information on poorly documented species in New Caledonia. Implications: Long-term monitoring of strandings can help design effective conservation measures. RESUME: Contexte: Les échouages constituent une source d'informations importante pour estimer la biodiversité des mammifères marins, en particulier dans les bassins océaniques pour lesquels les données sont rares, comme l'Océanie Objectif: Nous présentons ici les connaissances acquises à partir de 218 échouages enregistrés dans les eaux de Nouvelle-Calédonie (1877–2022). Méthodes: Nous avons étudié la distribution spatio-temporelle, les signatures isotopiques, les éléments traces, les mesures biométriques, la diversité génétique et le régime alimentaire des quatre taxons les plus fréquemment échoués (dugongs, 35% des échouages; cachalots, 19%; Delphinidae, 18% ; cachalots pygmées et nains, 14%). Principaux résultats: À partir de 1991, les signalements d'échouages ont augmenté (183 événements, 322 individus, 20 espèces de sept familles: Dugongidae, Physeteridae, Delphinidae, Kogiidae, Ziphiidae, Balaenopteridae, Otariidae), avec des points chauds identifiés sur la côte ouest de la Grande Terre (Bourail, Ouano, Nouméa) et dans la Baie de Prony. Les causes de décès n'ont pas été déterminées pour 84% des échouages, mais elles ont été identifiées dans la majorité des autopsies réalisées par des vétérinaires (24 des 29 individus de 10 espèces). Des informations précieuses concernant l'impact des activités anthropiques ont été recueillies pour certaines espèces préoccupantes, telles que le dugong, une espèce en voie de disparition (28% des échouages d'origine humaine). Depuis 2016, des formations et des activités de sensibilisation ont été dispensées aux gardes nature, aux vétérinaires et à divers agents publics pour soutenir leur engagement dans la surveillance scientifique des échouages de mammifères marins. Un site Web (www.rescue.ird.nc) a été développé pour faciliter la collecte et le stockage de données standardisées et pour fournir un accès public aux enregistrements d'échouages. Conclusion: Bien que le nombre d'individus signalés échoués ici reste modeste, cette étude apporte de nouvelles informations sur des espèces peu documentées en Nouvelle-Calédonie. Implications: La surveillance à long terme des échouages peut aider à concevoir des mesures de conservation efficaces. Map of strandings in New Caledonia; people gathered around a stranded whale; four commonly stranded species. Conservation of marine mammals in Oceania is limited by a lack of understanding of these relatively rare, yet emblematic species. Here, we report on significant biological and ecological data acquired from several decades of monitoring strandings in New Caledonia. This increased knowledge may help guide management measures locally and regionally. Photograph by Marine Mammal Stranding Center. This article belongs to the Collection Marine Mammals in the Pacific. [ABSTRACT FROM AUTHOR]