Improved bile-acid thin-layer chromatography to identify feces of neotropical carnivores

A modified thin-layer chromatography was used to identify carnivore feces based on their bile-acid patterns. Our method is safer and makes the identification of bile acids more objective. We applied the technique to feces of 2 sympatric canids in the Neotropics, the culpeo (Pseudalopex culpaeus) and South American gray fox (P. griseus), and describe bile-acid profiles of 7 other species from the region. Presence of chenodeoxycholic acid and hyodeoxycholic acids in feces of culpeo foxes allowed us to distinguish them from gray-fox feces with 85% accuracy. The method is most appropriate for carnivore species that consume small amounts of fiber and occur in dry habitats.