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

Abstract

The eastern South Pacific humpback whale population winters primarily off Colombia 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 summer. In recent years, however, humpback whales have also been observed feeding in the Corcovado 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 isolation 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.