|
Christophe Sauser, Karine Delord, Christophe Barbraud. (2021). Demographic sensitivity to environmental forcings: a multi-trait, multi-colony approach (Vol. 130).
|
|
|
. (2021). Once upon a time in the far south: Influence of local drivers and functional traits on plant invasion in the harsh sub-Antarctic islands (Vol. 32).
Abstract: Aim Here, we aim to: (a) investigate the local effect of environmental and anthropogenic factors on alien plant invasion in sub-Antarctic islands; and (b) explore whether and how functional traits affect alien species dependence on anthropogenic factors in these environments. Location Possession Island, Crozet archipelago (French sub-Antarctic islands). Methods Single-species distribution models were used to explore the effect of high-resolution topoclimatic and human-related variables on the occurrence of six alien plants colonizing French sub-Antarctic islands. Furthermore, plant responses to human-related variables and the effect of those variables in interaction with plant traits were analysed by means of a multi-species distribution model. This allowed identifying functional features mediating the influence of human activities on the occurrence probability of alien plant species. Results We observed two main invasion patterns: (a) species predicted to occur close to the introduction sites, whose occurrence probability appeared to be strongly affected by anthropogenic factors; and (b) species predicted to occur nearly everywhere on Possession Island, except in areas featuring particularly harsh climatic conditions. Differences in the influence of human-related variables on the occurrence of the alien species were mostly related to their life history, plant height and residence time, with perennial and low-statured species introduced earlier appearing less dependent on human-induced dispersal and disturbance. Conclusions We conclude that both topoclimatic and anthropogenic factors affect plant invasion on sub-Antarctic islands. Specifically, species predicted to occur close to their introduction sites appear much more dependent on human presence and activity, potentially due to the lack of key functional traits allowing them to spread successfully across Possession Island under the harsh sub-Antarctic climate. Yet, particularly severe abiotic conditions are a major constraint which equally limits the occurrence of all alien plants, irrespective of their dependence on anthropogenic factors.
Keywords: alien plants anthropogenic propagule pressure cold environments human disturbances plant invasiveness species distribution models topoclimate
Programme: 136
|
|
|
. (2021). The biology and feeding ecology of Arctic charr in the Kerguelen Islands (Vol. 98).
|
|
|
. (2021). The story of endurance: Biogeography and the evolutionary history of four Holarctic butterflies with different habitat requirements (Vol. 48).
Keywords: COI Ef-1? insect Lepidoptera mammoth steppe Pleistocene Quaternary RpS5 species distribution modelling
Programme: 1036
|
|
|
. (2021). Individual migration strategy fidelity but no habitat specialization in two congeneric seabirds (Vol. 48).
Keywords: guillemots light-level geolocation murres Uria aalge Uria lomvia
Programme: 388
|
|
|
. (2021). Diel at-sea activity of two species of great albatrosses: the ontogeny of foraging and movement behaviour (Vol. 52).
Abstract: The first year of life is a period of high mortality in animals. Reduced foraging capacities of naive individuals might be the primary cause of their mortality. These capacities are supposed to be progressively acquired during the first months of life. In this study, we investigate the ontogeny of flight capacities, by day and night, of first-year individuals, and compare it with adults from two closely related species of great albatrosses: Amsterdam Diomedea amsterdamensis and wandering Diomedea exulans albatrosses which forage in different environmental conditions. We used 71 tracks of 71 juvenile birds and 141 of 116 incubating adults to compare both age categories. In order to explore the effect of moon light on night activity, we elaborated a new formula which improves the precision of the proxy of moon illumination. By day, we found that juveniles of both species reach some adult foraging capacities in less than two months. By night, albatrosses have reduced activity increasing during the first weeks at sea for juveniles and changing in accordance with moon illumination for both juveniles and adults. A peak of flight activity at dawn and dusk was apparent for both species. Interspecific comparison underlined that Amsterdam albatrosses were more active than wandering albatrosses, suggesting a difference in food and foraging strategy. Overall, we highlighted how life history traits, environmental conditions and time of the day affect the foraging activity of two related species of seabirds.
Keywords: albatross diel activity pattern Diomedea flight behavior foraging activity moon illumination night activity seabirds
Programme: 109
|
|
|
Morten Frederiksen, Olivier Gilg, Glenn Yannic. (2021). Cross-icecap spring migration confirmed in a high-Arctic seabird, the Ivory Gull Pagophila eburnea (Vol. 163).
Keywords: ecological barrier Greenland icecap high-altitude migration
Programme: 1210
|
|
|
. (2021). Untangling local and remote influences in two major petrel habitats in the oligotrophic Southern Ocean (Vol. 27).
Abstract: Ocean circulation connects geographically distinct ecosystems across a wide range of spatial and temporal scales via exchanges of physical and biogeochemical properties. Remote oceanographic processes can be especially important for ecosystems in the Southern Ocean, where the Antarctic Circumpolar Current transports properties across ocean basins through both advection and mixing. Recent tracking studies have indicated the existence of two large-scale, open ocean habitats in the Southern Ocean used by grey petrels (Procellaria cinerea) from two populations (i.e., Kerguelen and Antipodes islands) during their nonbreeding season for extended periods during austral summer (i.e., October to February). In this work, we use a novel combination of large-scale oceanographic observations, surface drifter data, satellite-derived primary productivity, numerical adjoint sensitivity experiments, and output from a biogeochemical state estimate to examine local and remote influences on these grey petrel habitats. Our aim is to understand the oceanographic features that control these isolated foraging areas and to evaluate their ecological value as oligotrophic open ocean habitats. We estimate the minimum local primary productivity required to support these populations to be much <1% of the estimated local primary productivity. The region in the southeast Indian Ocean used by the birds from Kerguelen is connected by circulation to the productive Kerguelen shelf. In contrast, the region in the south-central Pacific Ocean used by seabirds from the Antipodes is relatively isolated suggesting it is more influenced by local factors or the cumulative effects of many seasonal cycles. This work exemplifies the potential use of predator distributions and oceanographic data to highlight areas of the open ocean that may be more dynamic and productive than previously thought. Our results highlight the need to consider advective connections between ecosystems in the Southern Ocean and to re-evaluate the ecological relevance of oligotrophic Southern Ocean regions from a conservation perspective.
Keywords: Antarctic Circumpolar Current (ACC) biogeography conservation grey petrels high seas hotspot open ocean primary productivity Procellaria cinerea seabirds
Programme: 109
|
|
|
Stephanie Jenouvrier, Judy Che-Castaldo, Shaye Wolf, Marika Holland, Sara Labrousse, Michelle LaRue, Barbara Wienecke, Peter Fretwell, Christophe Barbraud, Noah Greenwald, Julienne Stroeve, Philip N. Trathan. (2021). The call of the emperor penguin: Legal responses to species threatened by climate change (Vol. 27).
Abstract: Species extinction risk is accelerating due to anthropogenic climate change, making it urgent to protect vulnerable species through legal frameworks in order to facilitate conservation actions that help mitigate risk. Here, we discuss fundamental concepts for assessing climate change risks to species using the example of the emperor penguin (Aptenodytes forsteri), currently being considered for protection under the US Endangered Species Act (ESA). This species forms colonies on Antarctic sea ice, which is projected to significantly decline due to ongoing greenhouse gas (GHG) emissions. We project the dynamics of all known emperor penguin colonies under different GHG emission scenarios using a climate-dependent meta-population model including the effects of extreme climate events based on the observational satellite record of colonies. Assessments for listing species under the ESA require information about how species resiliency, redundancy and representation (3Rs) will be affected by threats within the foreseeable future. Our results show that if sea ice declines at the rate projected by climate models under current energy system trends and policies, the 3Rs would be dramatically reduced and almost all colonies would become quasi-extinct by 2100. We conclude that the species should be listed as threatened under the ESA.
Keywords: climate risk assessments Endangered Species Act foreseeable future population projections redundancy and representation (3Rs) resiliency sea ice projections species distribution treatment of scientific uncertainty
Programme: 109
|
|
|
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).
Keywords: bet-hedging intra-individual variability resource acquisition salt-water immersion logger seabirds Southern Oscillation Index
Programme: 109
|
|