Evidence of spatial structuring of eastern South Pacific humpback whale feeding grounds

Abstract

The eastern South Pacific humpback whale population winters primarily off Colom- bia and Ecuador, extending northward to the coasts of Panama and Costa Rica. It migrates south to the Fueguian Archipelago and Antarctic Peninsula waters for feeding during the austral sum- mer. In recent years, however, humpback whales have also been observed feeding in the Corco- vado Gulf, in the northern Chilean Patagonian channels, during the austral summer and fall. We examine photographically identified humpback whales in order to determine interchange or iso- lation of these aggregations. The apparent absence of movements of identified humpback whales among the 3 summering areas, and the differences in the proportion of white/black coloration on the fluke, suggest that each locality corresponds to a discrete feeding area for eastern South Pacific humpback whales.