Supplemental Methods and Results from Stable isotopes reveal winter feeding in different habitats in blue, fin and sei whales migrating through the Azores.

Potential range and seasonal movements of whale species. Table with mean (±SD) δ15N and δ13C values of potential prey. Estimates of the mean and standard deviation (SD) δ15N and δ13C values of regions used in Bayesian stable isotope mixing models run for blue, fin and sei whales. Summary of results of one-way ANOVAs and Student's t-test assessing differences in δ15N and δ13C values among whale species (blue, fin and sei whales) and among sexes, seasons and years for fin and sei whales. Plot of Mean and standard deviation (SD) δ15N and δ13C values of potential prey items from different regions and seasons. Percentage mean and SD contribution of different regional sources to the diet of blue, fin and sei whales estimated using Bayesian isotopic mixing models.