In wild populations, when settlement opportunities at the natal site are limited, some proportion of offspring undergo natal dispersal, that is, movement between the site of birth and the first breeding site. Dispersal is nearly ubiquitous in populations and it is a crucial driver of ecological and evolutionary patterns. Dispersal is assumed to have fitness costs, and short-term costs of dispersal incurred during the active dispersive phase are well documented. However, although information on immigrant (successful between-population dispersers) fitness is essential for our understanding of dispersal because of its major demographic and evolutionary consequences, information on the fitness costs incurred by immigrants is lacking, and the mechanistic processes underlying these costs remain almost entirely unknown. Major uncertainties in processes affecting immigrant fitness include a gap regarding our understanding of the performance of immigrants and residents (individuals remaining in their natal population) based on multiple trait approaches, a gap about the relative fitness of immigrants and residents in relation to sex, a gap regarding our understanding of the performance of immigrants and residents in long-lived species, and a gap in the nature of the behavioural and physiological mechanisms determinant of the fitness differences between immigrants and residents. Thus, to move forward, it is essential to understand the demographic and evolutionary consequences of immigrant fitness in wild populations, as well as the underlying mechanisms. ECOMIGR will carry out a comprehensive study of the demographic, behavioural and physiological mechanisms through which fitness of immigrants and residents differ. The project will exploit unique individual phenotypic and capture-recapture data, the latest miniaturized bio-logging technologies, physiological markers, state of the art analytical methods and modelling techniques, and unique long-term databases on the demography of seabirds. Seabirds breed on islands in colonies or in restricted habitat patches, which make them particularly suitable to study dispersal and facilitate the identification of immigrants in monitored populations. The PI has demonstrated the feasibility of quantifying and comparing the fitness costs between immigrant and resident individuals in long-lived species with a multiple demographic trait approach using detailed individual and longitudinal demographic data collected during several decades. By investigating the demographic, phenotypic, behavioural and physiological causes of fitness related differences between immigrants and residents in several long-lived species, and assessing to what extent immigrants and residents differ in their responses to environmental stochasticity, ECOMIGR will represent a major breakthrough in dispersal ecology and eco-evolutionary biology, as well as in conservation biology and the study of the effects of climate change on endangered seabirds.

Beyond their role in artistic creation and symbolic expression of prehistoric societies, colouring materials were involved in different kind of activities related to technical and subsistence practices. The analytical developments of recent years, founded on the combination of naturalist (geology/ petrography) and archaeometric (mineralogical and elemental analysis) approaches, have provided a better understanding of the nature of these materials and allowed to investigate their geological origin. However, the application of these studies remains rare, even if colouring materials constitute an important potential of information for the understanding of technical and cultural behaviours, and the circulation of people and materials. There are several reasons for this scarcity of applications: 1/ the lack of knowledge about the evolutionary chains, i.e. the modifications of their characteristics due to bio-geochemical, anthropic and taphonomic transformations that occur from the deposit to their discovery: these modifications of their composition constitute biases that can limit the identification of the geological and geographical origin of the colouring materials; 2/ the diversity of the analytical protocols and the heterogeneity of data produced between laboratories and research teams: these biases limit the comparison of data between studies and limit the generalisation of these approaches; 3/ the difficulty of analysing and comparing the composition of blocks of colouring matter with that of residues on the surface of archaeological remains: while the protocols for analysing cohesive blocks are efficient and hardly invasive, the analysis of residues remains difficult and the analytical techniques used on the blocks do not provide the necessary spatial resolution for analysing these thin layers; 4/ the lack of robust geological references: the establishment of geological references at a regional or supra-regional scale requires considerable investment. The geological reference collections, established independently by researchers or teams as a result of projects centred on archaeological sites, are not easily accessible and reusable, notably because of standardisation issues. The objective of the Color-Sources project is to overcome these constraints in order to provide a new dynamic to the study of the origins of prehistoric colouring materials at a national and international scale, by developing and sharing knowledges and methodologies necessary to build geological reference collections and to compare them with archaeological collections. This objective will be achieved by developing an "open science" dynamic and the production of "FAIR" (Easy to Find, Accessible, Interoperable, Reusable) data. To this aim, Color-Sources will be supported by an interdisciplinary consortium in order a) to share the experience acquired in our various archaeological fields in order to better understand the evolutionary chains, to develop a common methodology for studying colouring materials and to implement it in a common field: the Dordogne and its periphery; b) to develop interoperable data acquisition protocols, to improve the statistical processing protocols for the data produced (particularly elementary data), and to develop an elementary analysis methodology by LA-ICP-MS/MS that could be applied to both blocks and residues of colouring materials in order to limit the biases induced by the use of several different techniques, c) to design an information system to save, reuse and disseminate the data acquired by the French community on the sources of raw colouring materials used in the Palaeolithic period.