"In order to quantify the effects of climate change and habitat destruction on bird migration routes, we require a reliable and non-fatal method of locating the end-points of migratory birds. There is also a vital need to accurately establish the origins of migratory birds to better monitor and control the dispersion of zoonotic diseases, such as avian flu. Traditional bird ringing methods have very low recovery rates and radio-satellite transmitters are only suitable for large-size bird species. This multi-disciplinary project is designed to test the veracity of combined state-of-the-art radiogenic (Sr-Pb) and stable (δD-δ18O- δ13C-δ15N) isotope analysis of bird feathers to monitor migration. Feathers are keratine-based tissues that are inert after growth and their isotopic signature will record a signal indicative of the environment of their production. We will study European-breeding Pied and Collared Flycatchers that migrate to Africa in winter. Feathers have been collected from 23 different sites across Europe during the breeding season and by sampling different parts of the plumage, feathers produced on both breeding and wintering grounds are collected simultaneously. To ground-truth the multi-isotope approach, we will undertake a detailed study of feathers from the island of Gotland (Sweden), which has a varied but well mapped geology. The isotopic signatures of feathers will be compared to environment indicators such as rainwater, soils, bird prey and vegetation. This will determine which environmental proxies best correlate with the bird feathers and the spatial/geographical resolution of Sr-Pb isotope ratios. Subsequently, studies of feathers from Europe will establish if the technique can distinguish breeding European locations and constrain the wintering locations in Africa. This will allow future study of the extent of climate change induced variation in migration routes by comparing the isotopic composition of new and existing feather collections."