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Résumé :
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The use of mass spectrometry to analyse the stable-isotope ratios of bird tissues has become an important new tool for research ornithologists in the last 20 years. Because stable isotopes vary geographically and according to specific biological processes in the environment, they provide a unique forensic means of understanding more about avian biology and ecology than we can learn using conventional techniques alone. The stable-isotope ratios present in different tissues of birds reflect the ratios in the environment at the time those tissues were constructed. However, because of the rapid turnover of some tissues compared with others, an individual bird will bear within its body constituents a record of its present and past exposure to different isotopic environments. Because the stable-isotope ratios of specific elements vary geographically (e.g. hydrogen along oceanic to continental gradients) and between habitats (e.g. nitrogen and carbon in marine versus terrestrial ecosystems), they offer a unique means of studying the ways migratory birds move between different parts of the planet and of understanding the habitats they exploit. This review looks at some of the innovative ways in which the technique has been used in a variety of recent studies of birds. The technique is not restricted to breaking new ground in high science; in terms of understanding migration strategies, the importance of breeding, migratory and wintering habitat and the feeding ecology of birds, the study of stable-isotope ratios is becoming ever more important in supporting conservation actions.
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