Abstract
In the northeastern Pacific Ocean, there are three “ecotypes” of killer whales that differ in diet, ecology, behavior, acoustics, genetics, and morphology. Previous attempts to describe the morphological differences among populations of killer whales ( Orcinus orca ) have been limited to descriptive accounts or categorical studies. We used elliptical Fourier analysis (EFA) to quantify shape differences of dorsal fins and pigmentation patterns among the ecotypes from photo‐identification data of more than 500 individuals. Variation in shapes of the dorsal fin, saddle patch, and eye patch were successfully quantified using EFA, and there were highly significant ( P