This proposal will continue a comparative study of the population biology and ecology of Adelie, Gentoo, and Chinstrap penguins at Admiralty Bay, King George Island, South shetland Islands, Antarctica (62 10'S, 58 30'W). The primary objective is to determine age-specific demographic parameters for sympatric populations of Pygoscelis penguins, and to compare these parameters between Adelie populations in different environments. Another objective is to compare the foraging behavior/ecology of the three species, and within each, to compare the feeding proficiency of young, inexperienced, firts-time breeders with older, established breeders. Results from the latter effort should help to explain patterns observed in the demographic data. Pygoscelis penguins are major predators of krill (Euphausia superba); these predators and their prey are major components of the antarctic marine food web. To thoroughly understand the structure and function of the Antarctic ecosystem, important information not yet available would be the factors that drive age structure and regulate population size of key trophic-level predators (penguins). Such information will result from the proposed study.
