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Scott A. Shaffer, Pierre Blévin, Christophe Barbraud, Olivier Chastel, Henri Weimerskirch. (2021). Comparative egg attendance patterns of incubating polar petrels (Vol. 9).
Abstract: The internal environment of eggs in most birds is regulated by transferring heat energy through contact incubation, maintaining nest microclimate, and frequent egg turning by the incubating parent on its nest. However, we lack information about egg attendance patterns in birds that breed in polar environments where variations in life history are expected to influence incubation behavior. Moreover, crevice/burrow nesting petrels in high-latitude regions are known for periodically leaving their egg unattended (hereafter ‘egg neglect’), but there is little reporting on the internal condition of unattended eggs. At Dumont d’Urville Station, Antarctica, we studied the incubation behavior of 24 snow (Pagodroma nivea) and 15 Cape (Daption capense) petrel pairs using egg loggers that recorded egg turning rates, orientation changes, and temperatures at 1 Hz for durations of 3–6 days.
Keywords: Biologging Cape petrel Egg neglect Egg temperatures Egg turning rates Snow petrel
Programme: 109
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Alice Bernard, Ana S. L. Rodrigues, Victor Cazalis, David Grémillet. (2021). Toward a global strategy for seabird tracking (Vol. 14).
Abstract: Electronic tracking technologies revolutionized wildlife ecology, notably for studying the movements of elusive species such as seabirds. Those advances are key to seabird conservation, for example in guiding the design of marine protected areas for this highly threatened group. Tracking data are also boosting scientific understanding of marine ecosystem dynamics in the context of global change. To optimize future tracking efforts, we performed a global assessment of seabird tracking data. We identified and mined 689 seabird tracking studies, reporting on > 28,000 individuals of 216 species from 17 families over the last four decades. We found substantial knowledge gaps, reflecting a historical neglect of tropical seabird ecology, with biases toward species that are heavier, oceanic, and from high-latitude regions. Conservation status had little influence on seabird tracking propensity. We identified 54 threatened species for which we did not find published tracking records, and 19 with very little data. Additionally, much of the existing tracking data are not yet available to other researchers and decision-makers in online databases. We highlight priority species and regions for future tracking efforts. More broadly, we provide guidance toward an ethical, rational, and efficient global tracking program for seabirds, as a contribution to their conservation.
Keywords: biogeography biologging biotelemetry ecological monitoring marine conservation oceanography spatial planning threatened species
Programme: 388
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Johanna Faure, Clara Péron, Nicolas Gasco, Félix Massiot-Granier, Jérôme Spitz, Christophe Guinet, Paul Tixier. (2021). Contribution of toothfish depredated on fishing lines to the energy intake of killer whales off the Crozet Islands: a multi-scale bioenergetic approach (Vol. 668).
Abstract: Fisheries modify prey availability for marine predators by extracting resources but also by providing them with new feeding opportunities. Among these, depredation, which occurs when predators feed on fish caught on fishing gear, is a behavior developed by many species as a way to acquire food through limited foraging effort. However, the extent to which depredated resources from fisheries contribute to the energetic requirements and affect the demography of depredating individuals is unknown. We investigated the contribution of Patagonian toothfish Dissostichus eleginoides depredated on longlines to the energetic requirements of killer whales Orcinus orca around the Crozet Islands (southern Indian Ocean) over the period 2007-2018. Our results indicate that during days when depredation occurred, depredating individuals fulfilled on average 94.1% of their daily energetic requirements with depredated toothfish. However, the contribution varied from 1.2 to 13.3% of the monthly energetic requirements and from 2.4 to 8.8% of the yearly energetic requirements of the total population. Together, these findings suggest that intake of depredated toothfish can be substantial at a fine scale (daily and individually), potentially leading to temporary provisioning effects and changes in predation pressures. These effects become minor (<10%), however, when considering the full population over a whole year. The contribution of depredated fish to the annual energetic requirements of the population has increased in recent years, likely due to larger fishing quotas and greater opportunities for whales to depredate, which stresses the importance of accounting for depredation in ecosystem-based management of fishing activity.
Keywords: Bioenergetic model Depredation Dissostichus eleginoides Ecosystem-based management Fisheries interaction Marine mammals Orcinus orca Top predator conservation
Programme: 109
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F. Thibon, L. Weppe, N. Vigier, C. Churlaud, T. Lacoue-Labarthe, M. Metian, Y. Cherel, P. Bustamante. (2021). Large-scale survey of lithium concentrations in marine organisms (Vol. 751).
Abstract: Trace metals such as Cu, Hg, and Zn have been widely investigated in marine ecotoxicological studies considering their bioaccumulation, transfer along trophic webs, and the risks they pose to ecosystems and human health. Comparatively, Li has received little attention, although this element is increasingly used in the high-tech, ceramics/glass, and medication industries. Here, we report Li concentrations in more than 400 samples, including whole organisms and different organs of bivalves, cephalopods, crustaceans, and fish. We investigated species from three contrasting biogeographic areas, i.e. temperate (Bay of Biscay, northeast Atlantic Ocean), tropical (New Caledonia, Pacific Ocean), and subpolar climates (Kerguelen Islands, southern Indian Ocean), among diverse trophic groups (filter-feeders to meso-predators) and habitats (benthic, demersal, and pelagic). Although Li is homogeneously distributed in the ocean (at 0.18 μg/mL), Li concentrations in soft tissues vary greatly, from 0.01 to 1.20 μg/g dry weight. Multiple correspondence analyses reveal two clusters of high and low Li concentrations. Li distributions in marine organisms appear to be mostly geographically independent, though our results highlight a temperature dependency in fish muscles. Li is consistently bio-reduced through the trophic webs, with filter-feeders showing the highest concentrations and predatory fish the lowest. Strong variations are observed among organs, consistent with the biochemical similarity between Na and Li during transport in the brain and in osmoregulatory organs. Fish gills and kidneys show relatively high Li concentrations (0.26 and 0.15 μg/g, respectively) and fish brains show a large range of Li contents (up to 0.34 μg/g), whereas fish liver and muscles are Li depleted (0.07 ± 0.03 and 0.06 ± 0.08 μg/g, respectively). Altogether, these results provide the first exhaustive baseline for future Li ecotoxicology studies in marine coastal environments.
Keywords: Bio-reduction Bioaccumulation Biogeography Ecotoxicology Multiple correspondence analyses Trophic webs
Programme: 109
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Florian Orgeret, Ryan R. Reisinger, Tegan Carpenter-Kling, Danielle Z. Keys, Alexandre Corbeau, Charles-André Bost, Henri Weimerskirch, Pierre A. Pistorius. (2021). Spatial segregation in a sexually dimorphic central place forager: Competitive exclusion or niche divergence? (Vol. 90). Bachelor's thesis, , .
Abstract: Sexual competition is increasingly recognized as an important selective pressure driving species distributions. However, few studies have investigated the relative importance of interpopulation versus intrapopulation competition in relation to habitat availability and selection. To explain spatial segregation between sexes that often occurs in non-territorial and central place foragers, such as seabirds, two hypotheses are commonly used. The ‘competitive exclusion’ hypothesis states that dominant individuals should exclude subordinate individuals through direct competition, whereas the ‘niche divergence’ hypothesis states that segregation occurs due to past competition and habitat specialization. We tested these hypotheses in two populations of an extreme wide-ranging and sexually dimorphic seabird, investigating the relative role of intrapopulation and interpopulation competition in influencing sex-specific distribution and habitat preferences. Using GPS loggers, we tracked 192 wandering albatrosses Diomedea exulans during four consecutive years (2016–2019), from two neighbouring populations in the Southern Ocean (Prince Edward and Crozet archipelagos). We simulated pseudo-tracks to create a null spatial distribution and used Kernel Density Estimates (KDE) and Resource Selection Functions (RSF) to distinguish the relative importance of within- versus between-population competition. Kernel Density Estimates showed that only intrapopulation sexual segregation was significant for each monitoring year, and that tracks between the two colonies resulted in greater overlap than expected from the null distribution, especially for the females. RSF confirmed these results and highlighted key at-sea foraging areas, even if the estimated of at-sea densities were extremely low. These differences in selected areas between sites and sexes were, however, associated with high interannual variability in habitat preferences, with no clear specific preferences per site and sex. Our results suggest that even with low at-sea population densities, historic intrapopulation competition in wide-ranging seabirds may have led to sexual dimorphism and niche specialization, favouring the ‘niche divergence’ hypothesis. In this study, we provide a protocol to study competition within as well as between populations of central place foragers. This is relevant for understanding their distribution patterns and population regulation, which could potentially improve management of threatened populations.
Keywords: bio-logging central place foraging ecological niche theory intraspecific competition kernel density estimates resource selection functions sexual segregation wandering albatross
Programme: 109,394
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Francesco Enrichi, Dorthe Dahl-Jensen, Jørgen Peder Steffensen, Carlo Barbante. (2021). Theoretical and Experimental Analysis for Cleaning Ice Cores from EstisolTM 140 Drill Liquid (Vol. 11).
Abstract: To reconstruct climate history of the past 1.5 Million years, the project: Beyond EPICA Oldest Ice (BEOI) will drill about 2700 m of ice core in East Antarctica (2021–2025). As drilling fluid, an aliphatic ester fluid, EstisolTM 140, will be used. Newly drilled ice cores will be retrieved from the drill soaked in fluid, and this fluid should be removed from the cores. Most of it will be vacuum-cleaned off in a Fluid Extraction Device and wiped off with paper towels. Based on our experiences in Greenland deep ice coring, most of the residual fluid can be removed by storing the cores openly on shelves in a ventilated room. After a week of “drying”, the cores have a dry feel, handling them do not give “wet” gloves and they can easily be marked with lead pencils. This paper presents a theoretical investigation and some simple testing on the “drying” process. The rates of sublimation of ice and evaporation of fluid have been calculated at different temperatures. The calculations show that sublimation of the ice core should not occur, and that evaporation of fluid should be almost negligible. Our test results support these calculations, but also revealed significant fluid run-off and dripping, resulting in the removal of most of the fluid in a couple of days, independent of temperature and ventilation conditions. Finally, we discuss crucial factors that ensure optimal long-term ice core preservation in storage, such as temperature stability, defrosting cycles of freezers and open core storage versus storage of cores in insulated crates.
Keywords: Beyond EPICA drilling Estisol ice cores
Programme: 1202
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Samantha C. Patrick, Julien G. A. Martin, Caroline C. Ummenhofer, Alexandre Corbeau, Henri Weimerskirch. (2021). Albatrosses respond adaptively to climate variability by changing variance in a foraging trait (Vol. 27).
Abstract: The ability of individuals and populations to adapt to a changing climate is a key determinant of population dynamics. While changes in mean behaviour are well studied, changes in trait variance have been largely ignored, despite being assumed to be crucial for adapting to a changing environment. As the ability to acquire resources is essential to both reproduction and survival, changes in behaviours that maximize resource acquisition should be under selection. Here, using foraging trip duration data collected over 7 years on black-browed albatrosses (Thalassarche melanophris) on the Kerguelen Islands in the southern Indian Ocean, we examined the importance of changes in the mean and variance in foraging behaviour, and the associated effects on fitness, in response to the El Niño Southern Oscillation (ENSO). Using double hierarchical models, we found no evidence that individuals change their mean foraging trip duration in response to a changing environment, but found strong evidence of changes in variance. Younger birds showed greater variability in foraging trip duration in poor conditions as did birds with higher fitness. However, during brooding, birds showed greater variability in foraging behaviour under good conditions, suggesting that optimal conditions allow the alteration between chick provisioning and self-maintenance trips. We found weak correlations between sea surface temperature and the ENSO, but stronger links with sea-level pressure. We suggest that variability in behavioural traits affecting resource acquisition is under selection and offers a mechanism by which individuals can adapt to a changing climate. Studies which look only at effects on mean behaviour may underestimate the effects of climate change and fail to consider variance in traits as a key evolutionary force.
Keywords: bet-hedging intra-individual variability resource acquisition salt-water immersion logger seabirds Southern Oscillation Index
Programme: 109
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Aurore Ponchon, Amandine Gamble, Jérémy Tornos, Karine Delord, Christophe Barbraud, Justin M. J. Travis, Henri Weimerskirch, Thierry Boulinier. (2021). Similar at-sea behaviour but different habitat use between failed and successful breeding albatrosses (Vol. 678).
Abstract: Breeding failure is expected to induce behavioural changes in central place foragers. Indeed, after a failed reproductive attempt, breeding individuals are relieved from having to return to their breeding site for reproductive duties and thus are less constrained than successful breeders in their movements during the remainder of the breeding season. Accordingly, they are expected to adjust their behaviour, travelling longer in distance and/or time to reach foraging grounds. They are also expected to use different foraging areas to decrease local intra-specific competition with successful breeders. We compared the at-sea behaviour and habitat use of successful and failed Indian yellow-nosed albatrosses nesting in Amsterdam Island, Southern Indian Ocean, during 2 chick-rearing seasons. Failed breeders exhibited the same at-sea foraging behaviour, travelling as far and as long as successful breeders. They also spent the same amount of time on their nest between at-sea trips. Nevertheless, habitat models revealed partial spatial segregation of failed breeders, which used specific foraging areas characterized by deeper and colder waters in addition to the areas they shared with successful breeders. Our study shows the importance of combining a range of analytical methods (spatial analysis, behavioural inferences with advanced movement models and habitat models) to infer the at-sea behaviour and habitat use of seabirds. It also stresses the importance of considering individual breeding status when aiming to understand the spatial distribution of individuals, especially when this information may have conservation implications.
Keywords: Behavioural state Breeding failure Foraging behaviour Habitat models Inter-individual variability Procellariiformes Thalassarche carteri
Programme: 109
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Philip Bertrand, Joël Bêty, Nigel G. Yoccoz, Marie-Josée Fortin, Hallvard Strøm, Harald Steen, Jack Kohler, Stephanie M. Harris, Samantha C. Patrick, Olivier Chastel, P. Blévin, Haakon Hop, Geir Moholdt, Joséphine Maton, Sébastien Descamps. (2021). Fine-scale spatial segregation in a pelagic seabird driven by differential use of tidewater glacier fronts (Vol. 11).
Abstract: In colonially breeding marine predators, individual movements and colonial segregation are influenced by seascape characteristics. Tidewater glacier fronts are important features of the Arctic seascape and are often described as foraging hotspots. Albeit their documented importance for wildlife, little is known about their structuring effect on Arctic predator movements and space use. In this study, we tested the hypothesis that tidewater glacier fronts can influence marine bird foraging patterns and drive spatial segregation among adjacent colonies. We analysed movements of black-legged kittiwakes (Rissa tridactyla) in a glacial fjord by tracking breeding individuals from five colonies. Although breeding kittiwakes were observed to travel up to ca. 280 km from the colony, individuals were more likely to use glacier fronts located closer to their colony and rarely used glacier fronts located farther away than 18 km. Such variation in the use of glacier fronts created fine-scale spatial segregation among the four closest (ca. 7 km distance on average) kittiwake colonies. Overall, our results support the hypothesis that spatially predictable foraging patches like glacier fronts can have strong structuring effects on predator movements and can modulate the magnitude of intercolonial spatial segregation in central-place foragers.
Keywords: Behavioural ecology Biogeography
Programme: 330
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Maud Quéroué, Christophe Barbraud, Frédéric Barraquand, Daniel Turek, Karine Delord, Nathan Pacoureau, Olivier Gimenez. (2021). Multispecies integrated population model reveals bottom-up dynamics in a seabird predator–prey system (Vol. 91). Bachelor's thesis, , .
Abstract: Assessing the effects of climate and interspecific relationships on communities is challenging because of the complex interplay between species population dynamics, their interactions, and the need to integrate information across several biological levels (individuals, populations, communities). Usually used to quantify single-species demography, integrated population models (IPMs) have recently been extended to communities. These models allow fitting multispecies matrix models to data from multiple sources while simultaneously accounting for uncertainty in each data source. We used multispecies IPMs accommodating climatic variables to quantify the relative contribution of climate vs. interspecific interactions on demographic parameters, such as survival and breeding success, in the dynamics of a predator–prey system. We considered a stage-structured predator–prey system combining 22 yr of capture–recapture data and population counts of two seabirds, the Brown Skua (Catharacta lönnbergi) and its main prey the Blue Petrel (Halobaena caerulea), both breeding on the Kerguelen Islands in the Southern Ocean. Our results showed that climate and predator–prey interactions drive the demography of skuas and petrels in different ways. The breeding success of skuas appeared to be largely driven by the number of petrels and to a lesser extent by intraspecific density dependence. In contrast, there was no evidence of predation effects on the demographic parameters of petrels, which were affected by oceanographic factors. We conclude that bottom-up mechanisms are the main drivers of this skua–petrel system.
Keywords: Bayesian inference demography environmental variation integrated population model matrix population model Nimble predator–prey interactions
Programme: 109
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