Assessing Dual Hair Sampling for Isotopic Studies of Grizzly Bears

Résumé du livre

RATIONALE: The stable isotope ratios of carbon (?13C values), nitrogen (?15N values) and sulfur (?34S values) in bear hair can be used to obtain information on dietary history. Sample protocols often require hair sampling from multiple anatomical locations; however, there remains a question as to whether this is necessary for isotopic studies of hair. The purpose of this study was to determine whether significant differences can be observed for the ?13C, ?15N and ?34S values between paired hair samples taken from the rump and shoulder of grizzly bears (Ursus arctos). METHODS: Paired hair samples were collected from the rump and the shoulder of 81 grizzly bears in the Yukon, Canada. Hair samples were analyzed using a thermal combustion elemental analyzer coupled with a continuous flow isotope ratio mass spectrometer. RESULTS: Statistical comparisons of paired hair samples for both males and females showed no meaningful differences in ?13C, ?15N and ?34S values in hair taken from the rump and shoulder, and any observed differences fell within the instrumental error. CONCLUSIONS: Based on these results, hair may be safely sampled on either the rump or the shoulder without loss of isotopic information and thus this finding allows for refinement of sampling.