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.