Trophic discrimination factors of stable carbon and nitrogen isotopes in hair of corn fed wild boar

Abstract

Stable isotope measurements are increasingly being used to gain insights into the nutritional ecology ofmany wildlife species and their role in ecosystem structure and function. Such studies require estimations of trophic discrimination factors (i.e. differences in the isotopic ratio between the consumer and its diet). Although trophic discrimination factors are tissue- and species- specific, researchers often rely on generalized, and fixed trophic discrimination factors that have not been experimentally derived. In this experimental study, captive wild boar (Sus scrofa) were fed a controlled diet of corn (Zea mays), a popular and increasingly dominant food source for wild boar in the Czech Republic and elsewhere in Europe, and trophic discrimination factors for stable carbon (Δ 13 C) and nitrogen (Δ 15 N) isotopes were determined from hair samples. The mean Δ 13 C and Δ 15 N in wild boar hair were -2.3 ‰ and +3.5 ‰, respectively. Also, in order to facilitate future derivations of isotopicmeasurements along wild boar hair, we calculated the average hair growth rate to be 1.1 mm d -1. Our results serve as a baseline for interpreting isotopic patterns of free-ranging wild boar in current European agricultural landscapes. However, future research is needed in order to provide a broader understanding of the processes underlying the variation in trophic discrimination factors of carbon and nitrogen across of variety of diet types.