Fig. 5
Historical changes δ15N in the source amino acid (phenylalanine) of feathers grown during the non-breeding season (moult) in recent and historical samples of three penguin species breeding at New Island, Falkland/Malvinas Islands. Recent and historical samples were compared using t-tests, and significance levels are marked with asterisks (* for P < 0.05, and *** for P < 0.001)