Abstract: Scientific results about space physics in the solar system and obtained from space missions are presented, concentrating on observations from the past decade. After giving the most exhaustive possible list of missions having journeyed in the solar system these past twenty years, the paper presents new insights gathered on the solar wind focusing in particular on results obtained with SOHO, STEREO, ACE and Wind. Then, new results are also presented regarding the terrestrial space environment focusing specifically on data gathered by Cluster, Polar, THEMIS, GEOTAIL and Double Star.

Abstract: The action of predators, such as diurnal raptors, owls, mammals or humans, influence the nature of small vertebrate fossil assemblages but currently their taphonomic features are still poorly understood. In this study, we investigate the taphonomic signature of the snowy owl (Bubo scandiacus) based on an analysis of pellets collected at breeding sites located in Greenland and the Canadian Arctic. This taxon is widely distributed through the North Hemisphere and was an important predator in Pleistocene times. Taphonomic parameters suggest that, contrary to previous assumptions, B. scandiacus produces, on average, moderate digestion of incisors, molars and post-cranial elements, and should be classed as a Category 3 or Category 3/4 predator according to the terminology established by Andrews. Significant inter-site variability was observed for some of the damage considered (in particular, digestion on incisors), and a key finding is that variability and the associated statistical confidence intervals are crucial notions that should be taken into account when assessing taphonomical features, in order to reliably identify the potential predator(s) responsible for small vertebrate fossil accumulations.

Abstract:

IDENTIFYING THE MAIN STRUCTURE OF BENTHIC TROPHIC NETWORKS IS NECESSARY TO UNDERSTAND THE FUNCTIONING OF MARINE COMMUNITIES. FOR THAT PURPOSE, THE TRAINEE WILL ANALYSE NATURAL ¹³C AND ¹⁵N STABLE ISOTOPES AND FATTY ACID BIOMARKERS ON ECHINOID SPECIMENS TO ALLOW DISCRIMINATING AMONG THE FOOD SOURCES OF TARGET SPECIES, THE MEAN/BROAD POSITION OF THE TARGET SPECIES IN THE TROPHIC NETWORKS (FEEDING STRATEGIES), AND THE TROPHIC PLASTICITY OF THESE SPECIES. THREE TARGET ECHINOID SPECIES WITH ALREADY KNOWN A PRIORI CONTRASTED TROPHIC STRATEGIES WILL BE STUDIED: STERECHINUS DIADEMA, ABATUS CORDATUS, AND CTENOCIDARIS NUTRIX. ELEMENTAL (C/N) AND ISOTOPIC ANALYSES (¹³C, ¹⁵N) WILL ALSO BE PERFORMED ON DIFFERENT ORGANIC MATTER SOURCES (DISSOLVED ORGANIC MATTER OF SEA WATER, SEDIMENT ORGANIC MATTER, MACROALGAE) AND COMPARED WITH OTHER PRIMARY AND SECONDARY CONSUMERS (SPONGES, KEY MARINE INVERTEBRATES). THIS WILL BE COMPLETED BY DIGESTIVE TRACK CONTENT ANALYZES OF SAMPLED SPECIMENS.

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.