"This project has the ambitious goal of providing new groundbreaking information on a poorly known, yet critical stage of the life of any animal, the EARLYLIFE. The originality and novelty of EARLYLIFE is to combine two fields in ecology generally considered independently: foraging ecology and demography.With the data obtained for a range of marine predators with contrasted life histories I will be in a position to test several long lasting hypotheses in ecology, in particular on the causes of mortality of young animals, learning abilities, as well as on the significance of delayed maturity in long lived animals. Ultimately the project will allow a robust evaluation of the potential effects of global changes on young animals, and its consequences for population dynamics and conservation of marine air breathing predators.I will carry out EARLYLIFE in three steps, with my CNRS research group that brings together top researchers with complementary specialties and skills in animal tracking, foraging ecology, demographic modeling. First, using newly developed state of the art developments in bio-telemetry, bio-logging and biochemical markers, I will study for the first time the foraging ecology (movement, habitat, energetic, diet) of 13 species of seabirds and seals during their first years of life at sea after independence. This will allow estimating critical parameters such as the timing and causes of death, the spatial variation in mortality, as well as the extent of improvement in foraging skills at early stages. Second I will model the ontogenic changes occurring during the early stage of life, and contrast them with the foraging abilities of mature animals using our tracking data base. Finally, using our unique long term demographic data base I will examine to what extent, and how, environmental variability affects juvenile mortality, and models the potential effects of climate change and human activities on population dynamics."