Fig. 4

δ15NAA results divided into trophic, intermediate, source and metabolic groupings based on established fractionation patterns35,36,38. Abbreviations: Total hydrolysable amino acids (THAA), glutamic acid (Glx), aspartic acid (Asx), alanine (Ala), leucine (Leu), isoleucine (Ile), proline (Pro), valine (Val), glycine (Gly), serine (Ser), phenylalanine (Phe), lysine (Lys), threonine (Thr). Connecting lines are shown to help visualize different patterns among species.