Factors Affecting Adult Foraging and Chick Growth of Adélie Penguins ( Pygoscelis adeliae ) off the Western Antarctic Peninsula: A Modeling Study

• Main Author: Chapman, Erik W.
• Format: Text
• Language: unknown
• Published: ODU Digital Commons 2009
• Subjects: Antarctic Peninsula; Chick growth; Foraging; Pygoscelis adeliae; Biology; Ecology and Evolutionary Biology; Oceanography; Antarctic; Antarc*; Antarctic Krill; Antarctic silverfish; Euphausia superba
• Online Access: https://digitalcommons.odu.edu/oeas_etds/36; https://doi.org/10.25777/hw25-3b31; https://digitalcommons.odu.edu/context/oeas_etds/article/1034/viewcontent/Chapman_3362636.pdf

Coupled individual-based models that simulate Adélie penguin ( Pygoscelis adeliae) chick growth and adult foraging behavior during the chick growth period were developed and used to explore factors that influence chick fledging mass and adult foraging energetics off the western Antarctic Peninsula (WAP). Adélie penguin colonies in this region are undergoing changes in population size that have been correlated with climate-driven alteration of the marine and terrestrial environment. Simulations were selected to highlight possible mechanistic linkages between climate variability and chick growth and adult foraging processes. These processes were the focus of this study because chicks that fledge at a greater mass are more likely to recruit to the breeding population and Adélie penguin population dynamics can link directly with recruitment and fledging mass. Simulations using the chick-growth model tested the influence on penguin chick fledging mass of variability in (1) timing of Antarctic krill ( Euphausia superba) spawning, (2) chick diet composition [Antarctic silverfish (Pleuragramma antarcticum) combined with Antarctic krill compared to an all-Antarctic krill diet], (3) provisioning rate, and (4) the extent to which chicks become wet (from rain or melting snow). Simulations coupling the adult-foraging and chick-growth models investigated the influence on adult mass, foraging energetics, and chick growth of variability in (1) prey-availability characteristics (prey ingestion rate and distance between colony and prey), (2) the extent to which adults prioritize self-maintenance over chick provisioning, (3) adult digestion rate while foraging (a poorly studied physiological rate), and (4) adult diet composition [Antarctic krill combined with Antarctic silverfish (50% female) compared to all-Antarctic krill (50% and 100% female)]. In the chick-growth model simulations, shifting peak Antarctic krill spawning from early December to early March reduced fledging mass by 12%, enough to reduce a chick's probability of ...