Photographic evidence of interchange between East Australia (BS E-1) and West Australia (BS-D) humpback whale breeding populations

Documentation of humpback whale movements between east and west Australian breeding grounds have been restricted to limited historical data from ‘Discovery’ marks, and implied from song analysis and molecular data. We report on the first inter-ocean movement of a humpback whale between the Pacific Ocean, east Australia (BS-E1) and the Indian Ocean, west Australia (BS-D) confirmed by photo-ID. A single humpback whale from BS-E1 (1987) was re-sighted to BS-D (1995) breeding grounds. The identification photographs of this single whale were then compared to fifteen fluke ID catalogues containing 15,011 fluke identifications (not reconciled for duplications between catalogues) collected from 1981 - 2011, and one catalogue containing 3,555 left and 3,572 right lateral body images collected from 1990 – 2010. Catalogues searched represent individual humpback whale fluke IDs from Breeding Stocks A, B, B1, B2, C1, C2, C3, D, E1, E2, E3, F, F2, G; New Zealand (migratory corridor); and feeding areas of Antarctic Peninsula, Areas I-VI and Chile, and lateral body IDs from BS-D. This re-sight record across breeding stocks provides further evidence of longitudinal movement of humpback whales in the southern hemisphere and highlights the value of both opportunistic data collection and the importance of comparing identified individuals among catalogue holders working in adjacent and non-adjacent breeding regions.