Responses of Arctic marine birds to winter environmental constraints in the context of climate change
Harsh environmental conditions encountered in North Atlantic during wintertime, characterized by frequent extreme weather events, are among the most challenging constraints for endothermic animals.Seabirds, which experience this environment for many months per year, play a central role in North Atla...
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Other Authors: | , , , , , |
Format: | Doctoral or Postdoctoral Thesis |
Language: | French |
Published: |
HAL CCSD
2009
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Subjects: | |
Online Access: | https://hal.archives-ouvertes.fr/tel-01098578 https://hal.archives-ouvertes.fr/tel-01098578/document https://hal.archives-ouvertes.fr/tel-01098578/file/These_J%20Fort_final.pdf |
Summary: | Harsh environmental conditions encountered in North Atlantic during wintertime, characterized by frequent extreme weather events, are among the most challenging constraints for endothermic animals.Seabirds, which experience this environment for many months per year, play a central role in North Atlantic food webs, notably as top predators and indicators of marine ecosystems. In the current context of climate change, pronounced in North Atlantic waters, it is therefore a major objective tounderstand how seabirds respond and adapt to these environmental constraints shaping their survival and their population dynamics.We used a multidisciplinary approach (combining microelectronics, stable isotopic analyses, bioenergetics modelling and demography) focused on individual energy balance, to study the ecophysiological plasticity of the 3 main alcid species of the North Atlantic.We found that harsh winter conditions induce an energetic bottleneck for seabirds which might explain recurrent events of winter mass mortality, so called ‘seabird winter wrecks’. In response to increased energy expenditure, we showed that seabirds can adopt different strategies allowing higher energy intake. They can modulate their vertical (diving behaviour) and/or horizontal (migration) movements, as well as their trophic status, depending on the spatial and temporal availability of their prey.All together, these results constitute one of the first comprehensive studies of seabird winter ecology. These insights are essential to a better understanding of their population dynamics and constitute a firm foundation to future investigations of the impact of climate change on marine top predators. L’Atlantique Nord en hiver est un environnement rude soumis à des évènements climatiques extrêmes il fait partie des milieux les plus défavorables aux endothermes. Parmi eux, les oiseaux marins jouent un rôle majeur en temps que prédateurs supérieurs et bioindicateurs des écosystèmespélagiques. Dans le contexte actuel de changements globaux très ... |
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