Fin Whales (Balaenoptera physalus) Feeding on Euphausia mucronata in Nearshore Waters off North-Central Chile

This paper reports the presence and feeding activity of fin whales (Balaenoptera physalus) during the austral summers of 2004 and 2005 in coastal waters near the Reserva Nacional Pinguino de Humboldt, north of Chile. The main prey item of the species was identified as the euphausiid Euphausia mucronata. The presence of B. physalus is associated with a high concentration of potential prey probably produced by an upwelling system that is frequently detected slightly south of the study area during summer. This information is a contribution to the knowledge of distribution, feeding behavior, and diet of B. physalus. Additionally, it constitutes the first record of a direct observation of feeding activity of B. physalus along the Chilean coast.