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ArticleFull circumpolar migration ensures evolutionary unity in the Emperor penguin(Nature Publishing Group, 2016-06-14) Cristofari, Robin ; Bertorelle, Giorgio ; Ancel, André ; Benazzo, Andrea ; Le Maho, Yvon ; Ponganis, Paul J. ; Stenseth, Nils Christian ; Trathan, Phil N. ; Whittington, Jason D. ; Zanetti, Enrico ; Zitterbart, Daniel ; Le Bohec, Céline ; Trucchi, EmilianoDefining reliable demographic models is essential to understand the threats of ongoing environmental change. Yet, in the most remote and threatened areas, models are often based on the survey of a single population, assuming stationarity and independence in population responses. This is the case for the Emperor penguin Aptenodytes forsteri, a flagship Antarctic species that may be at high risk continent-wide before 2100. Here, using genome-wide data from the whole Antarctic continent, we reveal that this top-predator is organized as one single global population with a shared demography since the late Quaternary. We refute the view of the local population as a relevant demographic unit, and highlight that (i) robust extinction risk estimations are only possible by including dispersal rates and (ii) colony-scaled population size is rather indicative of local stochastic events, whereas the species’ response to global environmental change is likely to follow a shared evolutionary trajectory.
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ArticleBiologging of emperor penguins-attachment techniques and associated deployment performance(Public Library of Science, 2022-08-04) Houstin, Aymeric ; Zitterbart, Daniel ; Winterl, Alexander ; Richter, Sebastian ; Planas-Bielsa, Víctor ; Chevallier, Damien ; Ancel, André ; Fournier, Jérôme ; Fabry, Ben ; Le Bohec, CélineAn increasing number of marine animals are equipped with biologgers, to study their physiology, behaviour and ecology, often for conservation purposes. To minimise the impacts of biologgers on the animals’ welfare, the Refinement principle from the Three Rs framework (Replacement, Reduction, Refinement) urges to continuously test and evaluate new and updated biologging protocols. Here, we propose alternative and promising techniques for emperor penguin (Aptenodytes forsteri) capture and on-site logger deployment that aim to mitigate the potential negative impacts of logger deployment on these birds. We equipped adult emperor penguins for short-term (GPS, Time-Depth Recorder (TDR)) and long-term (i.e. planned for one year) deployments (ARGOS platforms, TDR), as well as juvenile emperor penguins for long-term deployments (ARGOS platforms) in the Weddell Sea area where they had not yet been studied. We describe and qualitatively evaluate our protocols for the attachment of biologgers on-site at the colony, the capture of the animals and the recovery of the devices after deployment. We report unprecedented recaptures of long-term equipped adult emperor penguins (50% of equipped individuals recaptured after 290 days). Our data demonstrate that the traditional technique of long-term attachment by gluing the biologgers directly to the back feathers causes excessive feather breakage and the loss of the devices after a few months. We therefore propose an alternative method of attachment for back-mounted devices. This technique led to successful year-round deployments on 37.5% of the equipped juveniles. Finally, we also disclose the first deployments of leg-bracelet mounted TDRs on emperor penguins. Our findings highlight the importance of monitoring potential impacts of biologger deployments on the animals and the need to continue to improve methods to minimize disturbance and enhance performance and results.
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ArticleThe emperor penguin - vulnerable to projected rates of warming and sea ice loss(Elsevier, 2019-10-08) Trathan, Phil N. ; Wienecke, Barbara ; Barbraud, Christophe ; Jenouvrier, Stephanie ; Kooyman, Gerald L. ; Le Bohec, Céline ; Ainley, David G. ; Ancel, André ; Zitterbart, Daniel ; Chown, Steven L. ; LaRue, Michelle ; Cristofari, Robin ; Younger, Jane ; Clucas, Gemma V. ; Bost, Charles-Andre ; Brown, Jennifer A. ; Gillett, Harriet J. ; Fretwell, Peter T.We argue the need to improve climate change forecasting for ecology, and importantly, how to relate long-term projections to conservation. As an example, we discuss the need for effective management of one species, the emperor penguin, Aptenodytes forsteri. This species is unique amongst birds in that its breeding habit is critically dependent upon seasonal fast ice. Here, we review its vulnerability to ongoing and projected climate change, given that sea ice is susceptible to changes in winds and temperatures. We consider published projections of future emperor penguin population status in response to changing environments. Furthermore, we evaluate the current IUCN Red List status for the species, and recommend that its status be changed to Vulnerable, based on different modelling projections of population decrease of ≥50% over the current century, and the specific traits of the species. We conclude that current conservation measures are inadequate to protect the species under future projected scenarios. Only a reduction in anthropogenic greenhouse gas emissions will reduce threats to the emperor penguin from altered wind regimes, rising temperatures and melting sea ice; until such time, other conservation actions are necessary, including increased spatial protection at breeding sites and foraging locations. The designation of large-scale marine spatial protection across its range would benefit the species, particularly in areas that have a high probability of becoming future climate change refugia. We also recommend that the emperor penguin is listed by the Antarctic Treaty as an Antarctic Specially Protected Species, with development of a species Action Plan.
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ArticleNo evidence of microplastic ingestion in emperor penguin chicks (Aptenodytes forsteri) from the Atka Bay colony (Dronning Maud Land, Antarctica)(Elsevier, 2022-09-01) Leistenschneider, Clara ; Le Bohec, Céline ; Eisen, Olaf ; Houstin, Aymeric ; Neff, Simon ; Primpke, Sebastian ; Zitterbart, Daniel ; Burkhardt-Holm, PatriciaMicroplastic (<5 mm; MP) pollution has been an emerging threat for marine ecosystems around the globe with increasing evidence that even the world's most remote areas, including Antarctica, are no longer unaffected. Few studies however, have examined MP in Antarctic biota, and especially those from Antarctic regions with low human activity, meaning little is known about the extent to which biota are affected. The aim of this study was to investigate, for the first time, the occurrence of MP in the emperor penguin (Aptenodytes forsteri), the only penguin species breeding around Antarctica during the austral winter, and an endemic apex predator in the Southern Ocean. To assess MP ingestion, the gizzards of 41 emperor penguin chicks from Atka Bay colony (Dronning Maud Land, Antarctica), were dissected and analyzed for MP >500 μm using Attenuated Total Reflection Fourier-transform Infrared (ATR-FTIR) spectroscopy. A total of 85 putative particles, mostly in the shape of fibers (65.9 %), were sorted. However, none of the particles were identified as MP applying state-of-the-art methodology. Sorted fibers were further evidenced to originate from contamination during sample processing and analyses. We find that MP concentrations in the local food web of the Weddell Sea and Dronning Maud Land coastal and marginal sea-ice regions; the feeding grounds to chick-rearing emperor penguin adults, are currently at such low levels that no detectable biomagnification is occurring via trophic transfer. Being in contrast to MP studies on other Antarctic and sub-Antarctic penguin species, our comparative discussion including these studies, highlights the importance for standardized procedures for sampling, sample processing and analyses to obtain comparable results. We further discuss other stomach contents and their potential role for MP detection, as well as providing a baseline for the long-term monitoring of MP in apex predator species from this region.
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ArticleJuvenile emperor penguin range calls for extended conservation measures in the Southern Ocean(The Royal Society, 2022-08-31) Houstin, Aymeric ; Zitterbart, Daniel ; Heerah, Karine ; Eisen, Olaf ; Planas-Bielsa, Víctor ; Fabry, Ben ; Le Bohec, CélineTo protect the unique and rich biodiversity of the Southern Ocean, conservation measures such as marine protected areas (MPAs) have been implemented. Currently, the establishment of several additional protection zones is being considered based on the known habitat distributions of key species of the ecosystems including emperor penguins and other marine top predators. However, the distribution of such species at sea is often insufficiently sampled. Specifically, current distribution models focus on the habitat range of adult animals and neglect that immatures and juveniles can inhabit different areas. By tracking eight juvenile emperor penguins in the Weddell Sea over 1 year and performing a meta-analysis including previously known data from other colonies, we show that conservation efforts in the Southern Ocean are insufficient for protecting this highly mobile species, and particularly its juveniles. We find that juveniles spend approximately 90% of their time outside the boundaries of proposed and existing MPAs, and that their distribution extends beyond (greater than 1500 km) the species' extent of occurrence as defined by the International Union for Conservation of Nature. Our data exemplify that strategic conservation plans for the emperor penguin and other long-lived ecologically important species should consider the dynamic habitat range of all age classes.
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ArticleReviews and syntheses: a framework to observe, understand and project ecosystem response to environmental change in the East Antarctic Southern Ocean(European Geosciences Union, 2022-11-23) Gutt, Julian ; Arndt, Stefanie ; Barnes, David Keith Alan ; Bornemann, Horst ; Brey, Thomas ; Eisen, Olaf ; Institute, Hauke ; Griffiths, Huw ; Institute, Christian ; Hain, Stefan ; Hattermann, Tore ; Held, Christoph ; Hoppema, Mario ; Isla, Enrique ; Janout, Markus ; Le Bohec, Céline ; Link, Heike ; Mark, Felix Christopher ; Moreau, Sebastien ; Trimborn, Scarlett ; Van Opzeeland, Ilse ; Pörtner, Hans-Otto ; Schaafsma, Fokje ; Teschke, Katharina ; Tippenhauer, Sana ; Van De Putte, Anton ; Wege, Mia ; Zitterbart, Daniel ; Piepenburg, DieterSystematic long-term studies on ecosystem dynamics are largely lacking from the East Antarctic Southern Ocean, although it is well recognized that they are indispensable to identify the ecological impacts and risks of environmental change. Here, we present a framework for establishing a long-term cross-disciplinary study on decadal timescales. We argue that the eastern Weddell Sea and the adjacent sea to the east, off Dronning Maud Land, is a particularly well suited area for such a study, since it is based on findings from previous expeditions to this region. Moreover, since climate and environmental change have so far been comparatively muted in this area, as in the eastern Antarctic in general, a systematic long-term study of its environmental and ecological state can provide a baseline of the current situation, which will be important for an assessment of future changes from their very onset, with consistent and comparable time series data underpinning and testing models and their projections. By establishing an Integrated East Antarctic Marine Research (IEAMaR) observatory, long-term changes in ocean dynamics, geochemistry, biodiversity, and ecosystem functions and services will be systematically explored and mapped through regular autonomous and ship-based synoptic surveys. An associated long-term ecological research (LTER) programme, including experimental and modelling work, will allow for studying climate-driven ecosystem changes and interactions with impacts arising from other anthropogenic activities. This integrative approach will provide a level of long-term data availability and ecosystem understanding that are imperative to determine, understand, and project the consequences of climate change and support a sound science-informed management of future conservation efforts in the Southern Ocean.
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ArticleAdvances in remote sensing of emperor penguins: First multi-year time series documenting trends in the global population(The Royal Society, 2024-03-13) LaRue, Michelle ; Iles, David T. ; Labrousse, Sara ; Fretwell, Peter T. ; Ortega, David ; Devane, Eileen ; Horstmann, Isabella ; Viollat, Lise ; Foster-Dyer, Rose ; Le Bohec, Celine ; Zitterbart, Daniel ; Houstin, Aymeric ; Richter, Sebastian ; Winterl, Alexander ; Wienecke, Barbara ; Salas, Leo ; Nixon, Monique ; Barbraud, Christophe ; Kooyman, Gerald L. ; Ponganis, Paul J. ; Ainley, David G. ; Trathan, Philip ; Jenouvrier, StephanieLike many polar animals, emperor penguin populations are challenging to monitor because of the species' life history and remoteness. Consequently, it has been difficult to establish its global status, a subject important to resolve as polar environments change. To advance our understanding of emperor penguins, we combined remote sensing, validation surveys and using Bayesian modelling, we estimated a comprehensive population trajectory over a recent 10-year period, encompassing the entirety of the species’ range. Reported as indices of abundance, our study indicates with 81% probability that there were fewer adult emperor penguins in 2018 than in 2009, with a posterior median decrease of 9.6% (95% credible interval (CI) −26.4% to +9.4%). The global population trend was −1.3% per year over this period (95% CI = −3.3% to +1.0%) and declines probably occurred in four of eight fast ice regions, irrespective of habitat conditions. Thus far, explanations have yet to be identified regarding trends, especially as we observed an apparent population uptick toward the end of time series. Our work potentially establishes a framework for monitoring other Antarctic coastal species detectable by satellite, while promoting a need for research to better understand factors driving biotic changes in the Southern Ocean ecosystem.
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ArticleRemote sensing of emperor penguin abundance and breeding success(Nature Research, 2024-05-29) Winterl, Alexander ; Richter, Sebastian ; Houstin, Aymeric ; Barracho, Teo ; Boureau, Matthieu ; Cornec, Clement ; Couet, Douglas ; Cristofari, Robin ; Eiselt, Claire ; Fabry, Ben ; Krellenstein, Adelie ; Mark, Christoph ; Mainka, Astrid ; Menard, Delphine ; Morinay, Jennifer ; Pottier, Susie ; Schloesing, Elodie ; Le Bohec, Celine ; Zitterbart, Daniel P.Emperor penguins (Aptenodytes forsteri) are under increasing environmental pressure. Monitoring colony size and population trends of this Antarctic seabird relies primarily on satellite imagery recorded near the end of the breeding season, when light conditions levels are sufficient to capture images, but colony occupancy is highly variable. To correct population estimates for this variability, we develop a phenological model that can predict the number of breeding pairs and fledging chicks, as well as key phenological events such as arrival, hatching and foraging times, from as few as six data points from a single season. The ability to extrapolate occupancy from sparse data makes the model particularly useful for monitoring remotely sensed animal colonies where ground-based population estimates are rare or unavailable.