Abstract
Stable isotopes analysis (SIA) of carbon and nitrogen provides valuable information about trophic interactions and animal feeding habits.We used near-infrared reflectance spectroscopy (NIRS) and support vector machines (SVM) to develop a model for screening isotopic ratios of carbon and nitrogen (δ (13)C and δ (15)N) in samples from living animals. We applied this method on dried blood samples from birds previously analyzed for δ (13)C and δ (15)N to test whether NIRS can be applied to accurately estimate isotopic ratios.Our results show a prediction accuracy of NIRS (R (2) > 0.65, RMSEP < 0.28) for both δ (13)C and δ (15)N, representing a 12% of the measurement range in this study.Our study suggests that NIRS can provide a time- and cost-efficient method to evaluate stable isotope ratios of carbon and nitrogen when substantial differences in δ (13)C or δ (15)N are expected, such as when discriminating among different trophic levels in diet.