DIVING AND FORAGING BEHAVIOR OF ADELIE PENGUINS IN AREAS WITH AND WITHOUT FAST SEA-ICE

The diving and foraging behaviours of Adelie penguins, Pygoscelis adel iae, rearing chicks at Hukuro Cove. Lutzow-Holm Bay, where the fast se a-ice remained throughout summer, were compared to those of penguins a t Magnetic Island, Prydz Bay, where the fast sea-ice disappeared in ea rly January. Parent penguins at Hukuro Cove made shallower (7.1-11.3 m ) but longer (90-111 s) dives than those at Magnetic Island (22.9 m an d 62 s). Dive duration correlated with dive depth at both colonies (r( 2) = 0.01 similar to 0.90), but the penguins at Hukuro Cove made longe r dives for a given depth. Parents at Hukuro Cove made shorter foragin g trips (8.1-14.4 h) with proportionally longer walking/swimming (divi ng <1 m) travel time (27-40% of trip duration) and returned with small er meals (253-293 g) than those at Magnetic Island, which foraged on a verage for 57.2 h, spent 2% of time walking/swimming <1 m) travel, and with meals averaging 525 g. Trip duration at both colonies correlated to the total time spent diving. Trip duration at Hukuro Covet but not at Magnetic Island, increased as walking/swimming <1 m) travel time i ncreased. These differences in foraging behaviour between colonies pro bably reflected differences in sea-ice cover and the availability of f oraging sites.