Abstract: Invasive alien species (IAS) are one of the most serious threats to the rich and unique biodiversity of the 13 French overseas territories (FOTs) scattered across three oceans and two continents. To address this critical issue, a dedicated Initiative has been conducted since 2005, with the support of a large panel of national and local experts and stakeholders. This paper summarizes the main results and benefits of this project after 7 years. As a first phase, an unprecedented overview of IAS and their impacts in all the FOTs was achieved. A total of 630 alien taxa were recorded, among which 258 plants, 52 terrestrial vertebrates and 32 invertebrates were identified as a threat, or a potential threat, to native species and/or natural habitats. Gaps in the knowledge about invasive species were also highlighted and a comprehensive set of recommendations was developed. Using a range of targeted collaborative actions and promoting the exchange of information and regional cooperation, the Initiative raised awareness of invasive species issues, improved access to information and strengthened local and regional capacities. In this paper, we report on the outcomes of the Initiative and what remains to be done with regards to the prevention of new introductions, early detection, rapid response and public awareness, as well as future challenges.

Abstract: How genetic diversity is maintained in philopatric colonial systems remains unclear, and understanding the dynamic balance of philopatry and dispersal at all spatial scales is essential to the study of the evolution of coloniality. In the King penguin, Aptenodytes patagonicus, return rates of post-fledging chicks to their natal sub-colony are remarkably high. Empirical studies have shown that adults return year after year to their previous breeding territories within a radius of a few meters. Yet, little reliable data are available on intra- and inter-colonial dispersal in this species. Here, we present the first fine-scale study of the genetic structure in a king penguin colony in the Crozet Archipelago. Samples were collected from individual chicks and analysed at 8 microsatellite loci. Precise geolocation data of hatching sites and selective pressures associated with habitat features were recorded for all sampling locations. We found that despite strong natal and breeding site fidelity, king penguins retain a high degree of panmixia and genetic diversity. Yet, genetic structure appears markedly heterogeneous across the colony, with higher-than-expected inbreeding levels, and local inbreeding and relatedness hotspots that overlap predicted higher-quality nesting locations. This points towards heterogeneous population structure at the sub-colony level, in which fine-scale environmental features drive local philopatric behaviour, while lower-quality patches may act as genetic mixing mechanisms at the colony level. These findings show how a lack of global genetic structuring can emerge from small-scale heterogeneity in ecological parameters, as opposed to the classical model of homogeneous dispersal. Our results also emphasize the importance of sampling design for estimation of population parameters in colonial seabirds, as at high spatial resolution, basic genetic features are shown to be location-dependent. Finally, this study stresses the importance of understanding intra-colonial dispersal and genetic mixing mechanisms in order to better estimate species-wide gene flows and population dynamics.

Abstract: SuperDARN International Workshop 2015

Abstract: We present a conjunction between the Swarm fleet and the European Incoherent Scatter Svalbard Radar (ESR) on 9 January 2014. The Swarm orbit in the early phase of the mission gives us the unique opportunity of sequencing the temporal evolution of the observed field-aligned current system in the nightside, near magnetic local midnight. These field-aligned currents are seen to move poleward through the radar field of view and to affect the observed ionosphere. The upward field-aligned current (FAC) is responsible, at least in part, for the heating of the ionospheric electrons. It is less clear whether the downward FAC cools the ionosphere. We use the TRANSCAR model of the ionosphere to quantify the thermoelectric effect that comes into play. Finally, we compare the plasma parameters measured by the Langmuir probe on board Swarm and the ESR and conclude on an agreement within the errors.