Seabird and dolphin associations: do seabirds benefit from feeding in association with dusky dolphins in Patagonia?

DEGRATI M; DANS SL; GARAFFO GV; CRESPO EA

JOURNAL OF THE MARINE BIOLOGICAL ASSOCIATION OF THE UNITED KINGDOM

CAMBRIDGE UNIV PRESS

Año: 2014 vol. 94 p. 1147 - 1153

0025-3154

The objective of this study was to describe the association between several species of seabirds and dusky dolphins. We investigated in what dolphins? activity the seabirds were most commonly associated and how the flock?s size change in relation with the number of dolphins in a group. Since both seabirds and dolphins may display different feeding strategies, we also investigated if benefits differ among seabird species. Data were collected in Golfo Nuevo (42º20´S, 65º00´W) onboard of a research vessel from 2001 to 2008. A total of 224 mixed groups of seabirds were encountered during this study. The seabirds-dolphins associations were mainly observed during dusky dolphins surface feeding. Shearwaters and kelp gulls were mainly observed in flocks related with dolphins, while Magellan penguins and cormorants generally appeared without dolphins. Seabirds could be conditioned to the foraging strategy of dolphins, since birds are associated with dolphins only during surface feeding strategy. This association probably helped seabirds in finding prey but no gave obvious benefit to dolphins.