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Author |
Christophe Barbraud, Karine Delord, Fabrice Le Bouard, Roald Harivel, Jérémie Demay, Adrien Chaigne, Thierry Micol |
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Title |
Seabird population changes following mammal eradication at oceanic Saint-Paul Island, Indian Ocean |
Type |
Journal |
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Year |
2021 |
Publication |
Journal for Nature Conservation |
Abbreviated Journal |
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Volume |
63 |
Issue |
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Pages |
126049 |
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Keywords |
Island restoration Petrels Population growth rate Rats Shearwaters Terns |
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Abstract |
The eradication of invasive mammals on islands is important for protecting seabird populations and insular ecosystems. However, the impacts of such eradications are insufficiently known because monitoring of potentially beneficiary species is often sporadic and limited. We performed a survey of all seabird species on Saint-Paul Island, southern Indian Ocean, 20 years after successful eradication of invasive black rat (Rattus rattus) and European rabbit (Oryctolagus cuniculus). Using complementary sampling designs including adaptive cluster sampling, stratified random sampling and entire sampling, we estimated population changes and colonization by new seabird species. A total of 13 seabird species were found breeding on Saint-Paul post-eradication compared to six before the eradication. Among the seven species that colonized the island, five (MacGillivray’s prion Pachyptila macgillivrayi, fairy prion P. turtur, white-bellied storm petrel Fregetta grallaria, Antarctic tern Sterna vittata, sooty tern Onychoprion fuscatus) had relictual populations breeding on a nearby islet, and one (brown skua Catharacta antarctica) was a new breeding species. We also found breeding subantarctic little shearwaters Puffinus elegans. For species that were breeding on the Saint Paul pre-eradication, the mean annual population growth rate was 1.030 ± 0.093 (SE). Species known to be vulnerable to rat predation (prions, great-winged petrel Pterodroma macroptera, flesh-footed shearwater Puffinus carneipes, subantarctic little shearwater, white-bellied storm petrel, Antarctic tern) had the highest population growth rates. Two decades after the eradication of invasive mammals on a remote oceanic island, seabird populations were high beneficiaries. These findings further highlight the importance of invasive mammal eradication on islands as a conservation tool. Results are encouraging for the planned eradication of invasive mammals from nearby Amsterdam Island, and suggest this will mainly benefit terns and small burrowing petrels. |
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109 |
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1617-1381 |
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yes |
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8459 |
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Author |
Mark A. Hindell, Clive R. McMahon, Ian Jonsen, Robert Harcourt, Fernando Arce, Christophe Guinet |
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Title |
Inter- and intrasex habitat partitioning in the highly dimorphic southern elephant seal |
Type |
Journal |
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Year |
2021 |
Publication |
Ecology and Evolution |
Abbreviated Journal |
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Volume |
11 |
Issue |
4 |
Pages |
1620-1633 |
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Keywords |
Antarctic Shelf foraging and diving behavior Kerguelen Plateau mid-year haul out predation risk Southern Ocean |
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Abstract |
Partitioning resources is a key mechanism for avoiding intraspecific competition and maximizing individual energy gain. However, in sexually dimorphic species it is difficult to discern if partitioning is due to competition or the different resource needs of morphologically distinct individuals. In the highly dimorphic southern elephant seal, there are intersexual differences in habitat use; at Iles Kerguelen, males predominantly use shelf waters, while females use deeper oceanic waters. There are equally marked intrasexual differences, with some males using the nearby Kerguelen Plateau, and others using the much more distant Antarctic continental shelf ( 2,000 km away). We used this combination of inter and intrasexual behavior to test two hypotheses regarding habitat partitioning in highly dimorphic species. (a) that intersexual differences in habitat use will not appear until the seals diverge in body size and (b) that some habitats have higher rates of energy return than others. In particular, that the Antarctic shelf would provide higher energy returns than the Kerguelen Shelf, to offset the greater cost of travel. We quantified the habitat use of 187 southern elephant seals (102 adult females and 85 subadult males). The seals in the two groups were the same size ( 2.4 m) removing the confounding effect of body size. We found that the intersexual differences in habitat use existed before the divergence in body size. Also, we found that the amount of energy gained was the same in all of the major habitats. This suggests that the use of shelf habitats by males is innate, and a trade-off between the need to access the large benthic prey available on shelf waters, against the higher risk of predation there. Intrasexual differences in habitat use are another trade-off; although there are fewer predators on the Antarctic shelf, it is subject to considerable interannual fluctuations in sea-ice extent. In contrast, the Kerguelen Plateau presents more consistent foraging opportunities, but contains higher levels of predation. Habitat partitioning in this highly dimorphic species is therefore the result of complex interplay of life history strategies, environmental conditions and predation pressure. |
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109,1201 |
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Bachelor's thesis |
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ISSN |
2045-7758 |
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yes |
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Serial |
8243 |
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Author |
Karine Delord, Cédric Cotté, Pascal Terray, Charles-André Bost, Henri Weimerskirch, Christophe Barbraud |
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Title |
Factors affecting adult body condition in the endangered northern rockhopper penguin |
Type |
Journal |
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Year |
2021 |
Publication |
Marine Biology |
Abbreviated Journal |
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Volume |
168 |
Issue |
3 |
Pages |
27 |
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Keywords |
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Abstract |
Understanding the factors that drive the dynamics of populations of long‐lived species presents a unique challenge for conservation management. Here, we investigated long-term change in the body condition of adult northern rockhopper penguins Eudyptes moseleyi at Amsterdam Island, southern Indian Ocean, which hosts 5–10% of the global population of this endangered species. Analysis of a long‐term dataset (1994–2016), concurrent to the population's rapid decline, revealed no trend in adult northern rockhopper penguin body condition over time at the stages considered in this study, i.e. breeding and moulting. However, body condition varied between years and sexes and part of this variation was explained by environmental factors. Males were on average in better condition than females whatever the stage and individuals on average were in better condition during the moulting compared to the breeding period. The environmental conditions [sea surface temperature anomaly (SSTa), Subtropical Indian Ocean Dipole (SIOD) and Southern Annular Mode (SAM)] appeared to impact non-linearly the body condition. Overall, females were in better condition for negative values of SAM, SIOD and SSTa. The body condition of males exhibited similar but less complex and more significant patterns, with decreasing body condition for increasing SAM, SIOD and SSTa. The absence of long-term trends in male and female body condition suggests that the very low reproductive output and declining population since 1997 is probably not the result of environmental conditions during pre-breeding and pre-moult and necessitates further research into possible drivers during the breeding season. |
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Programme |
109,394 |
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Bachelor's thesis |
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ISSN |
1432-1793 |
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yes |
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Serial |
7792 |
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Author |
Florian Orgeret, Ryan R. Reisinger, Tegan Carpenter-Kling, Danielle Z. Keys, Alexandre Corbeau, Charles-André Bost, Henri Weimerskirch, Pierre A. Pistorius |
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Title |
Spatial segregation in a sexually dimorphic central place forager: Competitive exclusion or niche divergence? |
Type |
Journal |
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Year |
2021 |
Publication |
Journal of Animal Ecology |
Abbreviated Journal |
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Volume |
90 |
Issue |
10 |
Pages |
2404-2420 |
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Keywords |
bio-logging central place foraging ecological niche theory intraspecific competition kernel density estimates resource selection functions sexual segregation wandering albatross |
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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. |
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109,394 |
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Bachelor's thesis |
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ISSN |
1365-2656 |
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yes |
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Serial |
8093 |
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Author |
Noor Johnson, Matthew L Druckenmiller, Finn Danielsen, Peter L Pulsifer |
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Title |
The Use of Digital Platforms for Community-Based Monitoring |
Type |
Journal |
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Year |
2021 |
Publication |
BioScience |
Abbreviated Journal |
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Volume |
71 |
Issue |
5 |
Pages |
452-466 |
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Keywords |
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Abstract |
Environmental observing programs that are based on Indigenous and local knowledge increasingly use digital technologies. Digital platforms may improve data management in community-based monitoring (CBM) programs, but little is known about how their use translates into tangible results. Drawing on published literature and a survey of 18 platforms, we examine why and how digital platforms are used in CBM programs and illuminate potential challenges and opportunities. Digital platforms make it easy to collect, archive, and share CBM data, facilitate data use, and support understanding larger-scale environmental patterns through interlinking with other platforms. Digital platforms, however, also introduce new challenges, with implications for the sustainability of CBM programs and communities’ abilities to maintain control of their own data. We expect that increased data access and strengthened technical capacity will create further demand within many communities for ethically developed platforms that aid in both local and larger-scale decision-making. |
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Programme |
1090,1206 |
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Bachelor's thesis |
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ISSN |
0006-3568 |
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yes |
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Serial |
8248 |
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Author |
Hajo Eicken, Finn Danielsen, Josephine-Mary Sam, Maryann Fidel, Noor Johnson, Michael K Poulsen, Olivia A Lee, Katie V Spellman, Lisbeth Iversen, Peter Pulsifer, Martin Enghoff |
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Title |
Connecting Top-Down and Bottom-Up Approaches in Environmental Observing |
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Journal |
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Year |
2021 |
Publication |
BioScience |
Abbreviated Journal |
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Volume |
71 |
Issue |
5 |
Pages |
467-483 |
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Keywords |
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Abstract |
Effective responses to rapid environmental change rely on observations to inform planning and decision-making. Reviewing literature from 124 programs across the globe and analyzing survey data for 30 Arctic community-based monitoring programs, we compare top-down, large-scale program driven approaches with bottom-up approaches initiated and steered at the community level. Connecting these two approaches and linking to Indigenous and local knowledge yields benefits including improved information products and enhanced observing program efficiency and sustainability. We identify core principles central to such improved links: matching observing program aims, scales, and ability to act on information; matching observing program and community priorities; fostering compatibility in observing methodology and data management; respect of Indigenous intellectual property rights and the implementation of free, prior, and informed consent; creating sufficient organizational support structures; and ensuring sustained community members’ commitment. Interventions to overcome challenges in adhering to these principles are discussed. |
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1090,1206 |
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Bachelor's thesis |
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0006-3568 |
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yes |
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Serial |
8249 |
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Author |
Jilda Alicia Caccavo, Thierry Raclot, Timothée Poupart, Yan Ropert-Coudert, Frédéric Angelier |
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Title |
Anthropogenic activities are associated with shorter telomeres in chicks of Adélie penguin (Pygoscelis adeliae) |
Type |
Journal |
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Year |
2021 |
Publication |
Polar Biology |
Abbreviated Journal |
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Volume |
44 |
Issue |
7 |
Pages |
1391-1399 |
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Keywords |
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Abstract |
Defining the impact of anthropogenic stressors on Antarctic wildlife is an active aim for investigators. Telomeres represent a promising molecular tool to investigate the fitness of wild populations, as their length may predict longevity and survival. We examined the relationship between telomere length and human exposure in Adélie penguin chicks (Pygoscelis adeliae) from East Antarctica. Telomere length was compared between chicks from areas with sustained human activity and on neighboring protected islands with little or no human presence. Adélie penguin chicks from sites exposed to human activity had significantly shorter telomeres than chicks from unexposed sites in nearby protected areas, with exposed chicks having on average 3.5% shorter telomeres than unexposed chicks. While sampling limitations preclude our ability to draw more sweeping conclusions at this time, our analysis nonetheless provides important insights into measures of colony vulnerability. More data are needed both to understand the proximate causes (e.g., stress, feeding events) leading to shorter telomeres in chicks from human exposed areas, as well as the fitness consequences of reduced telomere length. We suggest to further test the use of telomere length analysis as an eco-indicator of stress in wildlife among anthropized sites throughout Antarctica. |
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1091 |
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ISSN |
1432-2056 |
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Approved |
yes |
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Call Number |
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Serial |
8224 |
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Author |
Candice Michelot, Akiko Kato, Thierry Raclot, Yan Ropert-Coudert |
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Title |
Adélie penguins foraging consistency and site fidelity are conditioned by breeding status and environmental conditions |
Type |
Journal |
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Year |
2021 |
Publication |
PLOS ONE |
Abbreviated Journal |
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Volume |
16 |
Issue |
1 |
Pages |
e0244298 |
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Keywords |
Animal behavior Animal sexual behavior Animal sociality Birds Foraging Nesting habits Penguins Reproductive success |
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Abstract |
There is a growing interest in studying consistency and site fidelity of individuals to assess, respectively, how individual behaviour shapes the population response to environmental changes, and to highlight the critical habitats needed by species. In Antarctica, the foraging activity of central place foragers like Adélie penguins (Pygoscelis adeliae) is constrained by the sea-ice cover during the breeding season. We estimated the population-level repeatability in foraging trip parameters and sea-ice conditions encountered by birds across successive trips over several years, and we examined their foraging site fidelity linked to sea-ice concentrations throughout the chick-rearing season. Penguins’ foraging activity was repeatable despite varying annual sea-ice conditions. Birds’ site fidelity is constrained by both sea-ice conditions around the colony that limit movements and resources availability, and also behavioural repeatability of individuals driven by phenological constraints. Adélie penguins favoured sea-ice concentrations between 20–30%, as these facilitate access to open water while opening multiple patches for exploration in restricted areas in case of prey depletion. When the sea-ice concentration became greater than 30%, foraging site fidelity decreased and showed higher variability, while it increased again after 60%. Between two trips, the foraging site fidelity remained high when sea-ice concentration changed by ± 10% but showed greater variability when sea-ice concentrations differed on a larger range. In summary, Adélie penguins specialize their foraging behaviour during chick-rearing according to sea-ice conditions to enhance their reproductive success. The balance between being consistent under favourable environmental conditions vs. being flexible under more challenging conditions may be key to improving foraging efficiency and reproductive success to face fast environmental changes. |
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Programme |
1091 |
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ISSN |
1932-6203 |
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Approved |
yes |
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Call Number |
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Serial |
6428 |
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Author |
Michaël Beaulieu, Michael Dähne, Jane Köpp, Coline Marciau, Akiko Kato, Yan Ropert-Coudert, Thierry Raclot |
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Title |
Exploring the interplay between nest vocalizations and foraging behaviour in breeding birds |
Type |
Journal |
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Year |
2021 |
Publication |
Animal Behaviour |
Abbreviated Journal |
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Volume |
180 |
Issue |
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Pages |
375-391 |
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Keywords |
bird communication foraging behaviour reproductive partner vocalization |
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Abstract |
In many bird species, reproductive partners sing together each time they meet on the nest. Because these nest ceremonies typically correspond to the return of one partner from foraging and to the subsequent departure of the other partner, we hypothesized that the foraging decisions of departing birds may be facilitated by the vocalizations accompanying their partner's return on the nest, providing these vocalizations reflect foraging conditions. We examined this hypothesis in pairs of Adélie penguins, Pygoscelis adeliae, by longitudinally monitoring their nest vocalizations and their spatial distribution when foraging at sea across the guard stage, when both parents regularly alternate foraging at sea and chick attendance at the nest. We found that the acoustic characteristics of the vocalizations produced during nest relief ceremonies reflected some characteristics of the foraging trips of both the returning and departing partners. However, these acoustic characteristics differed between partners and were differently related to their foraging behaviour. Accordingly, departing individuals did not adopt the same foraging behaviour as that of returning individuals. Nest vocalizations therefore do not appear to represent cues facilitating the foraging decisions of departing birds, but they may rather reflect the arousal of partners, which differently correlates with the foraging behaviour of the returning and departing individuals. Our study highlights an interplay between the vocalizations produced on the nest by reproductive partners and their foraging behaviour, thereby broadening the scope of animal vocalizations and opening a novel perspective on the regulation of foraging strategies. However, our exploratory study also highlights the complexity of examining this interplay, as the effects of nest vocalizations on foraging decisions may be complicated by other factors (e.g. intrinsic foraging capacity). This calls for the use of additional and experimental approaches (e.g. vocalization playbacks) to clarify the role of nest vocalizations as potential mediators of foraging decisions. |
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1091 |
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ISSN |
0003-3472 |
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Approved |
yes |
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Call Number |
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Serial |
8760 |
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Author |
Éric Bernard, Jean-Michel Friedt, Madeleine Griselin |
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Title |
Snowcover Survey over an Arctic Glacier Forefield: Contribution of Photogrammetry to Identify “Icing” Variability and Processes |
Type |
Journal |
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Year |
2021 |
Publication |
Remote Sensing |
Abbreviated Journal |
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Volume |
13 |
Issue |
10 |
Pages |
1978 |
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Keywords |
arctic cryosphere moraine photogrammetry snow water equivalent snowcover spatial dynamics UAV-SfM |
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Abstract |
The global climate shift currently underway has significant impacts on both the quality and quantity of snow precipitation. This directly influences the spatial variability of the snowpack as well as cumulative snow height. Contemporary glacier retreat reorganizes periglacial morphology: while the glacier area decreases, the moraine area increases. The latter is becoming a new water storage potential that is almost as important as the glacier itself, but with considerably more complex topography. Hence, this work fills one of the missing variables of the hydrological budget equation of an arctic glacier basin by providing an estimate of the snow water equivalent (SWE) of the moraine contribution. Such a result is achieved by investigating Structure from Motion (SfM) image processing that is applied to pictures collected from an Unmanned Aerial Vehicle (UAV) as a method for producing snow depth maps over the proglacial moraine area. Several UAV campaigns were carried out on a small glacial basin in Spitsbergen (Arctic): the measurements were made at the maximum snow accumulation season (late April), while the reference topography maps were acquired at the end of the hydrological year (late September) when the moraine is mostly free of snow. The snow depth is determined from Digital Surface Model (DSM) subtraction. Utilizing dedicated and natural ground control points for relative positioning of the DSMs, the relative DSM georeferencing with sub-meter accuracy removes the main source of uncertainty when assessing snow depth. For areas where snow is deposited on bare rock surfaces, the correlation between avalanche probe in-situ snow depth measurements and DSM differences is excellent. Differences in ice covered areas between the two measurement techniques are attributed to the different quantities measured: while the former only measures snow accumulation, the latter includes all of the ice accumulation during winter through which the probe cannot penetrate, in addition to the snow cover. When such inconsistencies are observed, icing thicknesses are the source of the discrepancy that is observed between avalanche probe snow cover depth measurements and differences of DSMs. |
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4442 |
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