Influence des températures élevées sur les oiseaux : de la réponse physiologique aux conséquences écologiques

Climate change emerges as one of the main drivers of the current erosion of biodiversity. In this thesis, we study birds response to high temperatures, from the physiological mechanisms to the ecological consequences. We review the influence of high temperature on avian breeding success on a global scale. Effect of high temperature on breeding success is likely multifactorial, and reproduction in desert seems strongly depressed during high temperature events, highlighting the vulnerability of desert species to climate warming. Potential impact of climate change are likely to interact with urbanization. We consequently assessed weather effects on great tit (Parus major) reproductive success in a temperate climate across an urbanization gradient. Breeding initiation advanced with warmer temperature and reproductive success seem to increase with temperature, but results were contrasted between urban and forest systems. Overall, cooling requirements, hyperthermia and dehydration risk are predicted to increase with climate change. We review, identify and highlight the need to monitor physiological markers of avian dehydration. Finally, we assess zebra finches (Taenopygia guttata), and arid-adapted bird, response to an acute exposure. Response to heat was sex-dependent, and ultimately promoted hyperthermia and dehydration. This work underscores the need for a multi-scale and integrative approach to better understand and predict climate change impacts on birds.