Abstract: Albatrosses and other seabirds are generally highly philopatric, returning to natal colonies when they achieve breeding age. This is not universal, however, and cases of extraordinary vagrancy are rare. The Tristan Albatross (Diomedea dabbenena) breeds on Gough Island in the South Atlantic Ocean, with a small population on Inaccessible Island, Tristan da Cunha, ca 380 km away. In 2015, we observed an adult male albatross in Gonydale, Gough Island, which had been ringed on Ile de la Possession, Crozet Islands in 2009 when it was assumed to be an immature Wandering Albatross (D. exulans). We sequenced 1109 bp of the cytochrome b mitochondrial gene from this bird, and confirmed it to be a Tristan Albatross, meaning its presence on Crozet 6 years previous, and nearly 5000 km away, was a case of prospecting behaviour in a heterospecific colony. Given the challenges in identifying immature Diomedea albatrosses, such dispersal events may be more common than thought previously.

Abstract: Climate And Water Cycle Reconstruction Over The Last Centuries And Prediction Should Be Improved In The Southern Hemisphere (E.g. Last Ipcc Report). First, Direct Observations Are Scarce (E.g. In Antarctica, Mainly Basic Automatic Weather Station – Aws – Only Since The 50’s And Satellite Observations). As A Consequence, Climate And Water Cycle Reconstructions Are Largely Dependent On Proxy Measurements Such As Water Isotopes In Polar Ice Cores, Even Over The Last Century. Second, Climate And Water Cycle Reconstructions Using Models Should Be Improved. In Particular, Problems Have Been Identified For (1) Estimation Of Precipitation Amounts (Large Discrepancies Among Models Over The Austral Ocean And The Ice-sheet), (2) Description Of Particular Atmospheric Processes Associated With Cloud Microphysics And Exchanges Between Surface And Atmosphere In Polar Regions And (3) Seasonal To Interannual Evolution Of The Locations Of The Westerlies And Subtropical Jet And Associated Air Mass Trajectories. The Last Aspect Has Important Direct Consequences For The Atmospheric Dynamics In This Region But Also Indirect Consequences Such As The Links Between Westerlies, Co2 Outgassing And Sea Ice Extent In The Austral Ocean (Saunders Et Al. 2018; Menviel Et Al. 2018; Holland And Kwok, 2012). With The Objectives To Provide (1) A Better Description Of Water Cycle Dynamic In The Southern Ocean At Annual And Interannual Scales And (2) An Improved Transfer Function Between Climate / Water Cycle And Water Isotopes In This Region, A Bunch Of Instruments Measuring Continuously The Isotopic Composition Of Water In The Water Vapor And In The Precipitation Has Been Installed Over The Last Years Along A Transect From La Réunion To Antarctica.first Results From The Antarctic Instruments Reveal Clear Isotopic Signatures Of Large Scale Water Cycle Features Such As Atmospheric Rivers Dominating The Surface Mass Balance In Antarctica. In La Réunion, An Extensive Study Of The Drivers Of The Isotopic Composition Of The Water Vapor Showed That The Influence Of The Subtropical Westerly Jet Dominates The Water Isotopic Signal At Night. To Connect The Two Regions, An Instrument Is Running On Amsterdam Island Since November 2019 With First Results Showing A Clear Isotopic Signature During The High Pressure And Low Pressure Synoptic Events. Still, No In-depth Study Of The Data Trying To Connect The Isotopic Record In Amsterdam Island To Larger Scale Patterns Of The Water Cycle Has Been Initiated.the Goal Of This Internship Is To Provide The First Analyses Of The Isotopic (Water Vapor And Precipitation) Records On Amsterdam Island With A Comparison With Meteorological Data And Environmental Data Collected In Parallel On The Observatory Of Amsterdam Island (E.g. Gaseous Elemental Mercury). After These First Analyses Of The Data, Comparisons Will Be Performed With Water Isotopic Records In La Réunion Over Selected Events (Subtropical Jet Or Cold Fronts Intrusions). This Study Will Involve Analyses Of Meteorological Maps As Well As Backtrajectories.this Internship Requires Skills For (Python Or R Languages) And Involves Large Interactions Within A Large Research Team.

Abstract: In a fast-changing world, polar ecosystems are threatened by climate variability. Understanding the roles of fine-scale processes, and linear and nonlinear effects of climate factors on the demography of polar species is crucial for anticipating the future state of these fragile ecosystems. While the effects of sea ice on polar marine top predators are increasingly being studied, little is known about the impacts of landfast ice (LFI) on this species community. Based on a unique 39-year time series of satellite imagery and in situ meteorological conditions and on the world's longest dataset of emperor penguin (Aptenodytes forsteri) breeding parameters, we?studied the effects of fine-scale variability of LFI and weather conditions on?this?species' reproductive success. We found that longer distances to the LFI edge (i.e. foraging areas) negatively affected the overall breeding success but also the fledging success. Climate window analyses suggested that chick mortality was particularly sensitive to LFI variability between August and November. Snowfall in May also affected hatching success. Given the sensitivity of LFI to storms and changes in wind direction, important future repercussions on the breeding habitat of emperor penguins are to be expected in the context of climate change.