Supplementary methods and results from Artificial selection for predatory behaviour results in dietary niche differentiation in an omnivorous mammal

The diet of an individual is a result of the availability of dietary items and the individual's foraging skills and preferences. Behavioural differences may thus influence diet variation, but the evolvability of diet choice through behavioural evolution has not been studied. We used experimental evolution combined with a field enclosure experiment to test whether behavioural selection leads to dietary divergence. We analysed the individual dietary niche via stable isotope ratios of nitrogen (��15N) and carbon (��13C) in the hair of an omnivorous mammal, bank vole, from four lines selected for predatory behaviour and four unselected control lines. Predatory voles had higher hair ��15N values…