2003-2004 USAP Field Season

Biology & Medicine

Dr. Polly Penhale Program Manager

B-040-E	NSF/OPP 01-25985
Station: Special Project
RPSC POC: John Evans
Research Site(s): Copacabana Field Camp on St. George Island
Dates in Antarctica: Early January to mid February

Foraging behavior and demography of Pygoscelis penguins

	Dr. Wayne Z. Trivelpiece National Oceanic and Atmospheric Administration, Southwest Fisheries waynezt@aol.com

Foraging behavior and demography of Pygoscelis penguins

Deploying Team Members:

Stacey Buckelew . Simonetta Corsolini . David B. McWethy . Michael Polito . Susan G. Trivelpiece . Wayne Z. Trivelpiece

Research Objectives: Seabird research conducted at Admiralty Bay, King George Island, in the Antarctic Peninsula region has documented annual variability in the life history parameters of the population biology of three related penguin species: the Adélie, the gentoo, and the chinstrap (Pygoscelis adeliae, P. papua, and P. antarctica, respectively). This long-term study has collected 25 years of data on these three related species, including survival and recruitment, population size and breeding success, and diets and foraging ecology. We will extend the research linking penguin demography and foraging ecology to variability in the antarctic marine ecosystem. A major focus will be on the population biology data for the Adélie and gentoo penguins and the distribution and trophic interactions among the three species during the breeding season and the nonbreeding, winter period. Recent studies using satellite tags and time-depth recorders to examine postfledging foraging have provided the first detailed data on the wintering distributions of Adélie and chinstrap penguins in the Antarctic Peninsula. Specific topics include an examination of the size and sex of krill captured by penguins feeding chicks and krill collected concurrently by net hauls in the adjacent marine environment and the length-frequency distribution of krill collected from penguin diet samples. The winter survival of breeding adults and the recruitment of young (2- to 4-year-old) prebreeding penguins to their natal colony will be compared to the extent of sea ice in the winter before the breeding season. These variables are expected to be positively correlated for the Adélie but negatively correlated for the chinstrap penguin. Detailed studies of adult gentoo penguins, which do not disperse widely from their natal colony, will be conducted using satellite tags. The data we gather on the impact of environmental variation on the structure of upper-trophic-level predators such as the Pygoscelis penguins will improve our understanding of the structure and function of the Antarctic.