Stable isotope profile of autumnal migratory bird feathers on Italian Alps

In the study of migration of birds, there are many aspects to be deepened to comprehend both ecology of the species and their geographical connectivity between breeding and wintering grounds. In the last decades, stable isotopes of light elements such as hydrogen, oxygen, nitrogen, carbon and sulphur measured in cheratinous tissues such feathers are increasingly used in order to delineate origin of migrants and to define ecological aspects of birds. Here we present a complete isotopic profile of several passerine species migrating through Italian Alps during post-breeding season. Stable isotope ratios of hydrogen, oxygen, carbon, nitrogen and sulphur were measured in juvenile feathers of 807 individuals of 48 different specie ringed in central Italian Alps during post-breeding migration in the years 2010, 2011, 2012, and 2013. Birds were ringed in two ringing and monitoring stations of Progetto Alpi (http://progetto-alpi.muse.it/). No birds were mistreated, and the sampling took place in compliance with the national and international laws in force at the time of the study.