DIVE BOUT ORGANIZATION IN THE CHINSTRAP-PENGUIN AT SEAL-ISLAND, ANTARCTICA

Diving behavior of 2 breeding Chinstrap penguins (Pygoscelis antarctic a) was studied focusing first and primarily on dive bouts rather than dives themselves. Analysis of dive bout organization revealed (1) thou gh there are differences between solitary dives and dive bouts in dive duration and dive depth, the first dives of dive bouts do not differ from solitary dives in the dive parameters, (2) mean dive duration dur ing bout correlates positively to both mean dive depth during bout and mean surface interval during bout, while number of dives during bout negatively correlates to both cost (consumed energy) and duration of a dive cycle during bout.:These findings suggest the following possibil ities on foraging behavior of penguins: (1) their decision to repeat d iving depends on the result of the first dive at a site, and the first dives of bouts would tend to be searching or evaluating dives though they would be also successful foraging dives, (2) they repeat diving a t a foraging patch until foraging efficiency decrease to a threshold o f diminishing returns.