Effects of nutritional restriction on nitrogen and carbon stable isotopes in growing seabirds

When using stable isotopes as dietary tracers it is essential to consider eVects of nutritional state on isoto- pic fractionation. While starvation is known to induce enrichment of 15 N in body tissues, eVects of moderate food restriction on isotope signatures have rarely been tested. We conducted two experiments to investigate eVects of a 50-55% reduction in food intake on 15 N and 13 C values in blood cells and whole blood of tufted puYn...