October 2025 - MARMAM - devlists.uvic.ca

New method detects demographic decline in common dolphins from stranding data - Bay of Biscay case study
by Etienne Rouby 10 Oct '25

10 Oct '25

Dear MARMAM colleagues, Detecting population decline before it's too late: What dolphin teeth revealed about a hidden crisis We're excited to share our new study in Conservation Letters demonstrating the first evidence of declining viability in common dolphins (Delphinus delphis) in the Bay of Biscay. Using age-at-death data from 759 stranded specimens (1997-2019), we documented a dramatic decline in female longevity from 24 to 17 years - representing 2-3 fewer breeding events per female and a 2.4% reduction in population growth rate. This occurred despite stable abundance estimates, highlighting the Bay of Biscay as a demographic sink. The challenge: Making the most of stranding data Many of us collect teeth from stranded marine mammals and invest significant resources in aging specimens. Yet analyzing these cross-sectional age-at-death data has traditionally required restrictive assumptions (particularly stationarity) or complex models that are difficult to fit and don't easily accommodate covariates or allow temporal trend detection. This often means pooling data across years and potentially missing critical early warning signals of population decline. Our solution: A flexible, accessible framework We developed a pragmatic modeling approach using stratified random sampling and a flexible linear regression framework that can: * Detect temporal trends in survivorship without assuming stationarity * Work with realistic sample sizes (accurate estimates with n≥300) * Accommodate individual covariates (sex, area, etc.) * Provide operational demographic indicators for management The complete methodology is published and fully reproducible, with R code available on GitHub. Our Monte Carlo validation study (Ecological Modelling 2024) demonstrates the approach works even with sparse data and model misspecification. Full text (open access): Rouby et al. 2025. Conservation Letters: https://doi.org/10.1111/conl.13142 Methods paper: Rouby et al. 2024. Ecological Modelling: https://doi.org/10.1016/j.ecolmodel.2024.110647 Code repository: https://github.com/erouby/dolphin_viability_cons_letter We hope this framework proves useful for others working with stranding data to assess marine mammal population viability. We welcome questions and feedback! Best regards, Etienne Rouby --- Etienne Rouby, Ph.D. Postdoctoral Associate, University of Colorado Boulder Traditional Territory of the Arapaho, Cheyenne, and Ute www.etiennerouby.com<http://www.etiennerouby.com> Guest Editor BMC Environmental Science [cid:133d5c3c-4987-4507-bc95-e4067e9971f5]

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Bayesian Multilevel Modelling Using brms for Ecologists (BMME01)
by Oliver Hooker 10 Oct '25

10 Oct '25

PR stats still have some places on their Bayes GLMM course. Perfect for marine mammal researchers. Bayesian Multilevel Modelling Using *brms* for Ecologists (BMME01) www.prstats.org/course/bayesian-multilevel-modelling-using-brms-for-ecologi… <https://www.prstats.org/course/bayesian-multilevel-modelling-using-brms-for…> *Dates:* October 20–24 and 27–31, 2025 *Format:* Live online course (4 hours per day) Also recorded with a further 30 days access *Fee:* £450 (standard) | £400 (early bird for the first 5 registrations) SOLD OUT Why This Course Is Ideal for Marine Mammal Researchers Marine mammal research often involves *complex, hierarchical, and data-limited systems*, making it a perfect field for Bayesian multilevel modelling. Whether studying population dynamics, spatial distribution, behavioural ecology, or habitat use, marine mammal data commonly include multiple sources of variability—across individuals, sites, seasons, and time periods. This course provides the statistical framework and practical tools to address these challenges directly. *1. Handling Hierarchical and Nested Data* Marine mammal studies often involve repeated observations of individuals within groups, colonies, or geographic regions. Traditional statistical approaches can struggle with this kind of nested data, leading to pseudoreplication or biased inference. Multilevel (hierarchical) Bayesian models allow you to explicitly model variation at each level—individual, group, site, or species—while appropriately sharing information across them. *2. Dealing with Sparse or Unbalanced Data* Marine fieldwork can be logistically challenging, leading to unbalanced sampling designs, small sample sizes, or missing data. Bayesian inference provides a natural way to incorporate uncertainty and make robust estimates even when data are limited or unevenly distributed. *3. Modelling Detection and Observation Processes* Acoustic monitoring, photo-identification, and aerial surveys introduce observation errors and detection probabilities that can bias results if not properly modelled. Bayesian methods make it straightforward to include detection submodels and propagate uncertainty through the full inference process. *4. Incorporating Spatial and Temporal Structure* Marine mammal ecology is inherently spatial and temporal: migration routes, foraging ranges, and environmental drivers vary in space and time. The *brms* framework allows users to include spatial and temporal random effects, model autocorrelation, and integrate environmental covariates such as sea surface temperature or prey density. *5. Integrating Diverse Data Sources* Bayesian models excel at combining information from multiple datasets—such as telemetry, acoustic detections, and visual surveys—into a single, coherent analysis. This flexibility makes it easier to synthesise data from different monitoring programs or species. *6. Communicating Uncertainty Transparently* Conservation and management decisions for marine mammals often rely on uncertain data. Bayesian credible intervals and posterior predictive checks help researchers communicate this uncertainty clearly and defensibly to policymakers and stakeholders. *7. Direct Application to Marine Mammal Research Questions* By the end of the course, participants will be able to construct and interpret models directly relevant to marine mammal science, such as: - Estimating population abundance or occupancy across survey areas - Assessing habitat preferences and environmental predictors - Modelling survival, movement, and behavioural states - Quantifying effects of noise, disturbance, or climate variables ------------------------------ COURSE DESCRIPTION Bayesian methods are rapidly becoming the standard for ecological data analysis. They offer a flexible, transparent, and robust approach to dealing with uncertainty, hierarchical data structures, and complex ecological processes. If you work with ecological data and want to extend your modelling skills beyond classical statistics, this course will give you the tools and understanding to do so with confidence. *Bayesian Multilevel Modelling using brms for Ecologists (BMME01)* is an intensive 10-day live online course designed to provide ecologists, environmental scientists, and applied researchers with a solid grounding in Bayesian hierarchical modelling using the *brms* package in R. Over the course of ten sessions, participants will be guided step by step through the key concepts and practical applications of Bayesian inference, with a strong focus on real ecological examples. The course combines clear, structured teaching with extensive hands-on coding and interpretation. Course Overview Participants will begin by reviewing the fundamentals of Bayesian inference—priors, posteriors, and credible intervals—before moving on to the construction and interpretation of generalised linear and multilevel models. You will learn how to fit and diagnose models for a range of ecological data types, including continuous, count, binary, and zero-inflated data, as well as how to address common challenges such as spatial and temporal autocorrelation. Throughout, you will work with real-world datasets and gain practical experience in coding models using *brms*, an R package that provides a user-friendly interface to *Stan*, one of the most powerful Bayesian computation frameworks available. By the end of the course, you will have the skills to build, diagnose, and interpret complex Bayesian models relevant to your own ecological research. Key Topics Include - The foundations of Bayesian inference and model formulation - Understanding priors, posteriors, and credible intervals - Generalised linear models (GLMs) and extensions to hierarchical models - Random effects, nested structures, and partial pooling - Modelling count, binary, zero-inflated, and multivariate ecological data - Incorporating spatial and temporal structures - Model checking, convergence diagnostics, and posterior predictive checks - Interpreting and communicating uncertainty in ecological research Who Should Attend This course is aimed at ecologists, environmental scientists, conservation biologists, statisticians, and postgraduate researchers who already have a working knowledge of R (data import, manipulation, and basic plotting) and want to develop practical expertise in Bayesian multilevel modelling. No prior experience with Bayesian methods is required—concepts and techniques are introduced progressively, with plenty of guided practice and individual feedback. Why Choose This Course - Expert instruction from *Dr Niamh Mimnagh*, an experienced statistical ecologist and educator - A carefully balanced mix of lectures, demonstrations, and hands-on coding - Small-group format encouraging discussion and individual support - All course materials, R scripts, and datasets provided - Access to recorded sessions for 30 days after the course - Certificate of attendance upon completion Registration Places are limited to ensure an interactive learning experience. The early bird rate of £400 applies to the first five registrants. Standard registration is £450. For full details, schedule, and registration, visit: www.prstats.org/course/bayesian-multilevel-modelling-using-brms-for-ecologi… <https://www.prstats.org/course/bayesian-multilevel-modelling-using-brms-for…> -- Oliver Hooker PhD. PR stats

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New audio paper on 'whale listening' projects
by Alex South 10 Oct '25

10 Oct '25

Dear MARMAM community I'm happy to share this short audio paper (15 min listen) on the potential benefits of 'whale listening' projects for citizen science and public engagement with cetacean conservation. The paper reviews recent bioacoustic research on mysticete migration in the North Atlantic from an ecomusicological/environmental humanities perspective. It forms part of a special issue of Seismograf Peer on "sound, technology, and listening beyond the human." https://seismograf.org/node/20833 Please contact me if you would like a transcript of the text. Alex == Dr Alex South a.south(a)rcs.ac.uk Lecturer (part-time), Royal Conservatoire of Scotland Personal website https://alexsouth.org<https://alexsouth.org/> Bluesky https://bsky.app/profile/amsouth.bsky.social Orcid ID https://orcid.org/0000-0003-4223-1221 This email, including any attachments is intended for the above named only, and may contain privileged or confidential information. If you are not the intended recipient, any disclosure, copying, distribution or reliance upon the email is prohibited, and may be unlawful. If you are not the intended recipient, please destroy all copies and inform the sender by return email. While Royal Conservatoire of Scotland checks emails for known viruses, please note that neither Royal Conservatoire of Scotland nor the sender accepts any liability for viruses or other defects and it is your responsibility to scan any attachments included with this email. We take your privacy very seriously. Please find a copy of our Privacy Notice at: rcs.ac.uk/policy/privacy The Royal Conservatoire of Scotland is a company limited by guarantee Reg No.4703 (Scotland) and a charity registered in Scotland, No: SCO1585

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New tool: 'orcAI' Open-source detection and classification of killer whale acoustic signals
by Baumgartner Chérine 10 Oct '25

10 Oct '25

Hi everyone, We just published orcAI, a machine learning tool that detects and classifies a broad repertoire of killer whale acoustic signals, including vocalisations and incidental sounds (e.g. pulsed calls, whistles, breathing, tail slaps) and outputs time-stamped annotations from raw audio. The open access paper in Marine Mammal Science is now online at https://doi.org/10.1111/mms.70083. orcAI is trained on a data set of acoustic signals of Icelandic killer whales. You can use this tool as is on your own audio recordings (WAV format), and it can also be trained on your own recordings if you have sufficient annotated data for training. Installation of the model on your computer is straigthforward by downloading from github https://github.com/ethz-tb/orcAI. orcAI includes an easy to use command-line interface. We would be very interested in your experience with our tool. If you encounter any issues, please reach out or open an issue on GitHub! Kind regards, Cherine (on behalf of all co-authors) Cherine Baumgartner PhD candidate Theoretical Biology Group ETH Zurich, Switzerland Abstract Acoustic monitoring is an essential tool for investigating animal communication and behavior when visual contact is limited, but the scalability of bioacoustic projects is often limited by time-intensive manual auditing of focal signals. To address this bottleneck, we introduce orcAI—a novel deep learning framework for the automated detection and classification of a broad acoustic repertoire of killer whales (Orcinus orca), including vocalizations (e.g., pulsed calls, whistles) and incidental sounds (e.g., breathing, tail slaps). orcAI combines a ResNet-based Convolutional Neural Network (ResNet-CNN) with Long Short-Term Memory (LSTM) layers to capture both spatial features and temporal context, enabling the model to classify signals and to accurately determine their temporal boundaries in spectrograms. Trained on a comprehensive dataset from herring-feeding killer whales off Iceland, the framework was designed to be adaptable to other populations upon training with equivalent data. Our final model achieves up to 98.2% accuracy on test data and is delivered as an open-source tool with an easy-to-use command-line interface. By providing a ready-to-use model that processes raw audio and outputs annotations, orcAI serves as a useful tool for advancing the study of killer whale vocal behavior and, more broadly, for understanding marine mammal communication and ecology.

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WDC Marine Mammal Conservation Internship (Paid)
by Lauren Brandkamp 09 Oct '25

09 Oct '25

Whale and Dolphin Conservation is open to applications for our: Marine Mammal Conservation Internship <https://us.whales.org/about/get-involved/> <https://us.whales.org/about/get-involved/> Submission period: Open through October 24, 2025, 11:59 PM ET, or until we reach a maximum of 50 applications, whichever comes first. Internship Session Dates: 12/1/2025 – 2/28/2026 (start date can be flexible but internship must be completed by the end of February) IMPORTANT: WDC has a blind hiring process for candidate selection. To preserve our ability to fairly review applicants, please DO NOT contact us or have your reference reach out to us regarding the status of your application. We will contact all applicants with the result of your application. Please be patient as this may take a few weeks. Paid, temporary, full-time Whale and Dolphin Conservation’s North American office is offering a 12-week, entry-level Marine Mammal Conservation Internship to candidates with little to no prior experience. This opportunity will help to build skills relevant to the field of marine conservation while providing interns with insight into the inner workings of a non-profit as well as job skills transferable to any field.   This position is designed for those who do not yet have experience in marine conservation and outreach. We will prioritize candidates who do not have practical experience (internship, significant volunteering, employment) in this field outside of a classroom setting. Applicants should be eager to dive into new experiences and enjoy having a variety of tasks to work on. This position will help to assist staff in Marine Animal Rescue and Response<https://us.whales.org/whales-dolphins/science/marine-animal-rescue-and-resp…> (MARR), and Education and Outreach<https://us.whales.org/education/>. Work with the MARR team will involve being on beaches and near water but does not involve being in or swimming in water. This position will assist Education & Outreach staff with school and community events including our on-demand fishing<https://us.whales.org/our-goals/prevent-bycatch/ropeless-fishing/> school program. A large percentage of the candidate’s work week will take place in our office. Opportunities to deliver education programs or assist in animal strandings may occur outside of the office but cannot be guaranteed. The typical breakdown of office to fieldwork is 70% in the office and 30% in the field. Successful candidates will gain transferable skills in effective communication and public speaking, project management, developing and delivering presentations and other interpretive resources, working on a close-knit team, and record keeping.  LOGISTICS: Candidates must be able to demonstrate that they are legally eligible to work in the U.S. by the proposed starting date. Successful candidates will need to make their own arrangements, as needed, for housing and transportation to and from the WDC office in Plymouth, MA, USA. Please note that the cost of living in the Plymouth area is above the national average when considering this role. Successful candidates are expected to work 40 hours a week (including occasional evening and/or weekend work) for the 12-week period of the program; they will be compensated at a rate of $15/hour.   Applicants must be 18 years or older by the internship start date and fluent in English. WDC will assist interested students in obtaining credits for the program through their college or university. Candidates should be advised that WDC’s office is dog-friendly; up to three dogs may be in the office on any given day.  Candidates of all backgrounds are strongly encouraged to apply for this position. Whale and Dolphin Conservation embraces and encourages all voices<https://us.whales.org/about/waves-of-voices/> to participate in marine conservation. We recognize that the field of marine mammal research and conservation lacks people representing all backgrounds, including within our own organization. WDC is dedicated to creating opportunities which represent all voices, perspectives, and skills and. As a result, our hiring procedure is a blind process, and we do not accept cover letters or resumes. Candidates in this internship will: * Have effective verbal and/or written communications skills * Work well with different audiences and teams  * Have an interest in education/outreach initiatives  * Act effectively as a member of a close-knit team * Be able to problem solve in unanticipated situations * Have an attention to detail and follow policies and procedures * Possess a valid driver’s license and be willing to drive a large pick-up truck * Be able to pass a background check * Be able to lift or move heavy objects (around 50 pounds) and work outside in adverse weather conditions * Be comfortable working with deceased/decomposing animals * Have health insurance coverage and be free of (or able to manage) medical issues aggravated by exposure to animals including their fur and bodily fluids, which could contain transmissible diseases * Be legally able to work in the United States * As our work sometimes includes interactions with large crowds of people as well as direct contact with wild animals, we encourage our staff to stay up to date with vaccinations. CDC communicable disease recommendations are reviewed at frequent intervals and guide the updating of WDC's protocols to keep employees safe. Internship responsibilities include but are not limited to: * Researching and exploring potential education partnership opportunities * Writing blogs, creating social media content, and managing program websites * Developing outreach materials and grade school lesson plans connected to science standards * Delivering educational programs to K-12 students as well as adults/families at community events * Responding to stranded live and dead marine mammals in the field, including assisting with health assessments and examinations to determine cause of death * Answering WDC’s rescue hotline and handling reports from callers * Ensuring marine animal response preparedness by inventorying and restocking equipment, cleaning gear, fueling vehicles, etc. * Supporting WDC policy initiatives including efforts to protect critically endangered North Atlantic right whales. The programs this internship supports are as follows: Education  WDC’s formal and informal educational efforts include creating lesson plans, facilitating inquiry-based activities, developing and delivering presentations, managing outreach events, and more. Interns supporting this program will build a strong set of skills related to educational design and philosophy, public speaking and outreach, communications and marketing strategies (including social media), and contribute new ideas and plans on how to grow WDC’s educational programming.   Marine Animal Rescue and Response  WDC’s Marine Animal Rescue and Response Program (MARR) is responsible for responding to stranded marine mammals along about 300 miles of Massachusetts coastline. Interns will learn the skills needed to respond to pinnipeds (seals) and cetaceans (whales, porpoises, and dolphins), including standard data collection and data input (Level A and human interaction evaluations) and maintaining response readiness. It's important to note that stranding events are unpredictable and hands-on experience and species encountered will vary. Funding and support for this paid internship was generously provided by the National Fish and Wildlife Foundation. APPLY NOW<https://form.jotform.com/252805450742152>

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New publication - Acceleration metrics predict propulsive power at within‑dive temporal scales in California sea lions
by Mason Cole 09 Oct '25

09 Oct '25

On behalf of my coauthors I am excited to share our new publication, out today in Animal Biotelemetry: Cole, M.R., McHuron, E.A., Costa, D.P., Ponganis P.J., and McDonald B.I*.* Acceleration metrics predict propulsive power at within-dive temporal scales in California sea lions. *Anim Biotelemetry* 13, 32 (2025). https://doi.org/10.1186/s40317-025-00428-y *Abstract*: *Background* Locomotion can drive variation in an animal’s energy expenditure, but the energetic cost of movement is difficult to measure at fine time scales in free-living animals. The 3 axis acceleration metrics Dynamic Body Acceleration (DBA) and Minimum Specific Acceleration (MSA) are commonly used in biologging studies as a proxy for activity or energy expenditure. These metrics hold potential for relatively simple and affordable estimates of movement-based energy expenditure, but have not been validated for use at fine temporal scales (e.g., within dives) due to logistical limitations of metabolic measurement techniques. Here, we use rates of propulsive power (W kg−1) recently calculated at 5 s intervals in diving California sea lions to test whether DBA and MSA can predict propulsive power at two within-dive temporal scales. *Results* Mean DBA and MSA predicted mean propulsive power in both 5 s intervals and dive phases (descent or ascent). All relationships were linear and significant. For all data types, likelihood ratio tests indicated that full linear mixed-effects models including random effects of individual (slope and intercept) had the best fit. Filtering and smoothing raw DBA and MSA data improved linear mixed models, though models with raw data were also strong. Using fixed-effects models on individual animals, both DBA and MSA successfully detected a known trend of increasing power use in deeper dives. *Conclusions* When applied appropriately, DBA and MSA can be easily calculated proxies for propulsive power, even at fine temporal scales, in all circumstances we tested. We show that this is true even while avoiding the “Time Trap”; i.e., using mean rather than summed data. While this study focused on California sea lions, we expect these metrics will also predict relative power in other species that swim with similar mechanics. However, as inter-individual slope was important to model fit, and as the scope of our validation was limited by the circumstances that allowed propulsive power calculation, we reiterate the need for care when inferring energetic cost from acceleration metrics like DBA or MSA. Please email me at marcole(a)ucsc.edu if you have any questions. Cheers, Mason

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Job Opportunity: CEO of the World Cetacean Alliance
by Sophie Lewis 09 Oct '25

09 Oct '25

Dear colleagues, Are you passionate about driving cetacean conservation by enabling collaboration, empowering communities, and reducing human impact? We're currently accepting applications for a motivated, ambitious Chief Executive Officer to strengthen the work of the World Cetacean Alliance as a charity and global partnership. We're looking for a leader with a track record of success and strong communication, who is committed to marine conservation and willing to work at both strategic and operational levels to grow the organisation and meet our objectives. If this sounds like the opportunity you're looking for to make a lasting impact for cetaceans and the ocean, please find out more here: https://worldcetaceanalliance.org/vacancies/ Best wishes, The WCA Team -- *Sophie Lewis* Interim CEO *World Cetacean Alliance* Unit D, 132-134 Albion Street, Southwick, Brighton, BN42 4DP, UK. t: +44 (0) 1273 355011 e: sophie.lewis(a)worldcetaceanalliance.org *Help us Save Whales! Donate today! <https://worldcetaceanalliance.org/donate/>* The World Cetacean Alliance (WCA) is a Partnership of over 118 organisations and individuals in 40 countries worldwide working collaboratively to protect cetaceans and their habitats. World Cetacean Alliance, the Secretariat to the Partnership, is a UK registered Charity no. 1160484. The content of this e-mail is intended solely for the use of the individual or entity to whom it is addressed. If you have received this communication in error, be aware that forwarding it, copying it, or in any way disclosing its content to any other person, is strictly prohibited. If you have received this communication in error, please notify the author by replying to this e-mail immediately. Please consider the environment before printing this email or it's attachments. -- Please prefix all WCA emails with one of the following codes in the subject box WCA ANNOUNCE: Email is an announcement that requires no further action WCA AB: Action By. Includes a timeframe e.g. AB+2 means action within 2 days WCA AR: Action Required. No timeframe specified WCA SS: Social Share. Email is a request to share information via social media WCA PRIORITY: Email is important and should be read by all Partners

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New paper about franciscana dolphin bioacoustics
by Lis Bittencourt 09 Oct '25

09 Oct '25

Dear MARMAM colleagues, I am glad to share with you our recent publication describing the clicking behavior of franciscana dolphin with acoustical parameters and temporal patterns of different types of sound emissions. Bittencourt L, Carvalho RR, Pereira K, Santos-Neto EB, Lailson-Brito Jr. J, Bisi TL and Azevedo AF (2025) Acoustic parameter variation and emission patterns in franciscana dolphin (*Pontoporia blainvillei*) clicking behavior at high frequency. *Front. Mar. Sci.* 12:1641888. doi: 10.3389/fmars.2025.1641888 Abstract: Franciscana dolphins are small odontocetes that produce narrow-band high-frequency echolocation clicks. Autonomous acoustic monitoring and field survey acoustic sampling were used to record franciscana dolphins in Ilha Grande Bay, Brazil. Clicking sequences were automatically detected and analyzed, and then manually classified into different types; acoustic parameters from individual clicks were extracted. A total of 12505 clicks were detected, 152 clicking sequences were analyzed, of which 43 were click trains and 109 were click packets. Considering all clicks, they occurred from 88.7 kHz to 250 kHz, with a mean peak frequency of 132.4 ± 6.8 kHz. Click trains were longer than click packets, with larger inter-click intervals and mean peak frequencies of 123.6 ± 16.4 kHz and 119.9 ± 15.0 kHz, respectively. Franciscana dolphins emitted different types of clicking sequences. The use of patterned clicks by franciscana dolphins may be an important communication feature at very high frequencies. The paper is open access, but feel free to contact me about it. Kind regards, Lis . Dr. Lis Bittencourt Post-doctoral fellow at Rio de Janeiro State University MAQUA Lab

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New publication: extra-limit births and abortions of pinnipeds in Brazil
by Renan Lima 09 Oct '25

09 Oct '25

Dear MARMAM community, On behalf of my co-authors, I am pleased to share with you our latest publication: de Lima, R. C., Estima, S. C., Canabarro, P. L., Groch, K., da Conceição, F. P., Botta, S., ... & de Oliveira, L. R. (2025). Births and abortions in wild pinnipeds along the southern Brazilian coast. *Regional Studies in Marine Science*, 104526. https://www.sciencedirect.com/science/article/pii/S2352485525005171?via%3Di… Abstract: Pinnipeds exhibit diverse reproductive strategies influenced by ecological and environmental factors. Most species breed in well-established colonies that offer sheltered habitats, stable substrates, and reliable prey availability. However, rare reproductive events beyond range can provide insights into population dynamics, including shifts in distribution and emerging threats, such as habitat disturbance and disease transmission. Here, we document the first records of pinniped births and abortions on the Brazilian coast between 1979 and 2024. These events were documented as part of systematic marine mammal stranding programs conducted year-round in the states of Rio Grande do Sul and Santa Catarina. Four births were recorded, two southern elephant seals (Mirounga leonina) and two South American fur seals (SAFS) (Arctocephalus australis). In addition, 11 abortion events were recorded—two confirmed (one subantarctic fur seal, A. tropicalis, and one South American sea lion (SASL), Otaria flavescens) and nine inferred cases involving SASLs and SAFSs, and unidentified fur seals. We speculate that live births in Brazil resulted from young females’ inexperience, including limited prior reproductive activity and poorly developed site fidelity, as well as possible disorientation. However, given their rarity and the unsuitability of the sites where they occurred, such events are unlikely to indicate broader shifts in distribution. Abortions may have occurred as an attempt to reallocate resources for survival and/or as a direct response to stress, reflecting underlying life-history trade-offs influenced by individual condition and external pressures. While the number of reproductive events recorded is low and insufficient to draw population-level conclusions, these rare cases offer unique insights. Continued monitoring and interdisciplinary investigation are essential to understand their causes and broader conservation implications. Please feel free to email me if you are unable to access the article. Sincerely, Renan -- *Renan C. de Lima, PhD* Postdoctoral fellow Centre for Ecology and Conservation University of Exeter & Laboratório de Ecologia e Conservação da Megafauna Marinha - EcoMega Instituto de Oceanografia Universidade Federal do Rio Grande (FURG) *E-mail*: renancdl(a)gmail.com *RG:* www.researchgate.net/profile/Renan-Lima-2 *ORCID*: https://orcid.org/0000-0002-9311-7085

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Fwd: New paper on declining reproductive success in southern right whales
by Els Vermeulen 08 Oct '25

08 Oct '25

Dear colleagues, My co-authors and I are pleased to share with you the publication of our newly published article: Vermeulen,E., Wilkinson, C., Best, P.B., Findlay, K. 2025. Four decades of annual monitoring reveal declining reproductive success of migratory baleen whale. Scientific Reports 15: 34713 Abstract: Understanding and mitigating threats to species survival relies on the ability to track key demographic processes over time. Among these processes, reproduction stands out as a primary biological driver of population growth and resilience. Multiple factors affect reproductive success, including environmental variables and resource availability. Long-term trends in reproductive parameters of long-lived species can thus serve as indicators of ecosystem health over meaningful timescales. This study analyses the reproductive performance of southern right whales (*Eubalaena australis*) in South Africa using forty years of individual sighting histories. Results reveal that the median and average calving intervals increased post-2010, reaching an average maximum of 7.2 years in 2022. The average calving rate decreased significantly across the four decades, from 0.48 calves/year in the 1980s to 0.19 calves/year in the 2010s. Although based on observational data, these findings align with the hypothesis of a trade-off linked to the reduced maternal body condition in this population, likely indicative of diminished foraging success associated with recorded regional Antarctic sea ice declines and reduced prey availability. The study adds to the growing evidence that baleen whale reproduction is influenced by environmental change, reinforcing the need for long-term monitoring to understand population dynamics and their potential role as sentinels of ocean health. The paper is open access and can be downloaded here <https://link.springer.com/article/10.1038/s41598-025-18252-y?utm_source=rct…> With kind regards, Els Dr Els Vermeulen Senior Lecturer and Research Manager Mammal Research Institute Whale Unit Faculty of Natural and Agricultural Sciences University of Pretoria, South Africa +27 (0)60 9714301 / els.vermeulen(a)up.ac.za https://www.mammalresearchinstitute.science/whale-unit “For the love of whales, for the future of our oceans” -- This message and attachments are subject to a disclaimer. Please refer to http://upnet.up.ac.za/services/it/documentation/docs/004167.pdf <http://upnet.up.ac.za/services/it/documentation/docs/004167.pdf> for full details.

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