Feeding grounds of the eastern South Pacific humpback whale population include the South Orkney Islands

Abstract

This paper reports on two photo-identified humpback whales (Megaptera novaeangliae) that were sighted in different years in the proximity of the South Orkney Islands, at the boundary between the Scotia and Weddell seas (60^o54.5’S – 46^o40.4’W and 60^o42.6’S – 45^o33’W). One of the whales had been previously sighted off Ecuador, a breeding ground for the eastern South Pacific population. The other whale was subsequently resighted in Bransfield Strait, off the western Antarctic Peninsula, a well-documented feeding ground for the same population. These matches give support to a hypothesis that the area south of the South Orkney Islands is occupied by whales from the eastern South Pacific breeding stock. Consequently, we propose 40^oW as a new longitudinal boundary between the feeding grounds associated with the eastern South Pacific and western South Atlantic breeding stocks.

Keywords: Humpback whale; photo-identification; breeding stocks; migration; South Orkney Islands; Southern Ocean

(Published: 20 March 2012)

Citation: Polar Research 2012, 31, 17324, DOI: 10.3402/polar.v31i0.17324