Figure 5

Principal components analysis of 60 fatty acids in Illinois river otters ( Lontra canadensis ) and several of its candidate prey species. Of the candidate prey species considered here, the river otter fatty acid signatures are most similar to those of fish species as indicated by their proximity in the graph. This suggests that fish are the predominant component of the otter diet, though a better understanding of how river otters metabolize different fatty acids is necessary for a fuller inference of the PCA results for diet.