Identification of Cougar and Jaguar Feces through Bile Acid Chromatography

The use of feces for population size assessment and diet analysis of carnivore species depends on accurate feces identification. Fecal bile acid composition appears to be species specific among carnivores and therefore a useful method to identify fecal samples. To help identify 194 field-collected feces of cougars (Puma concolor) and jaguars (Felis onca), 2 sympatric carnivore species of the Chaco Region (Paraguay), we developed a method to determine feces origin using thin layer chromatography (TLC) bile acid patterns. Bile acids were extracted from 11 fecal samples from cougars and 10 from jaguars from different zoological gardens. Although cougar and jaguar feces contain the same identifiable bile acids, feces can be distinguished by the presence of a single unknown bile acid present consistently only among jaguar feces. The use of this bile acid as an indicator of feces origin, evaluated by means of 2 blind tests of 10 samples each, reached 80%. We also compared our results with a previous identification of the field collected feces based on physical characteristics. We suggest that TLC analysis of fecal bile acids is the best identification technique of cougar and jaguar feces technique available.