Fecal cortisol metabolites to assess stress in wildlife: evaluation of a field method in free ranging chamois

1. Non-invasive faecal cortisol metabolite (FCM) analysis is a well-established tool to quantify stress in captive and free-ranging species. While the method has great potential, its suitability in field studies might be limited when faecal samples from unknown individuals are used. Possible factors affecting final results and thus jeopardizing correct data interpretation are individual and sex-specific variation, storage conditions and uneven distribution of metabolites in the faeces. 2. We tested these factors on a population of free-ranging Alpine chamois Rupicapra rupicapra rupicapra in the Austrian Alps. Faecal samples (n = 183) were analysed with an established enzyme immunoassay (EIA). To further validate the assay for FCM in chamois, a high-performance liquid chromatography (HPLC) was performed. Sex-specific differences in metabolite excretion were evaluated. Effects of storage length and temperature on FCM were tested with two experiments. The distribution of metabolites in the...