October 3, 2017

Rationale: Stable isotope analysis (SIA) of whiskers has been used to identify temporal feeding habits, intra‐population diet variation, as well as individual dietary specialisation of marine and terrestrial carnivores. However, the potential of the method to disclose such dietary information for large wild felids is hampered by lack of information on species‐specific whisker growth rates, whisker growth patterns and whisker‐diet trophic discrimination factors (TDFs). Methods: Whisker growth rates and growth patterns were measured for four lions (Panthera leo) and one leopard (Panthera pardus) held at the National Zoological Gardens, Pretoria, South Africa. Actively growing whiskers of the felids were 'marked' four times over 185 days using 13C‐depleted, C3‐based giraffe (Giraffa camelopardalis) meat. The periods with low δ13C values, identified following serial sectioning of the regrown whiskers at 1 mm intervals and isotopic analysis, were then correlated to specific giraffe meat feeding bouts and hence growth periods. δ13C and δ15N whisker‐diet TDFs were estimated for five lions whose diet remained consistent over multiple years.