Foraging ecology Niche overlap

• Main Authors: Ari S. Friedlaender A, David W. Johnston A, William R. Fraser C, Jennifer Burns D, Patrick N. Halpina, Daniel P. Costa E
• Other Authors: The Pennsylvania State University CiteSeerX Archives
• Format: Text
• Language: English
• Published: 2010
• Subjects: Antarctic; Antarctic Peninsula; Marguerite; Marguerite Bay; The Antarctic; Antarc*; Antarctic Krill; Crabeater Seals; Euphausia superba; Lobodon carcinophagus; Megaptera novaeangliae; Pygoscelis adeliae
• Online Access: http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.467.9477; http://pal.lternet.edu/docs/bibliography/Public/401lterc.pdf

a b s t r a c t Adélie penguins (Pygoscelis adeliae), carabeater seals (Lobodon carcinophagus), humpback (Megaptera novaeangliae), and minke whales (Balaenoptera bonaernsis) are found in the waters surrounding the Western Antarctic Peninsula. Each species relies primarily on Antarctic krill (Euphausia superba) and has physiological constraints and foraging behaviors that dictate their ecological niches. Understanding the degree of ecological overlap between sympatric krill predators is critical to understanding and predicting the impacts on climate-driven changes to the Antarctic marine ecosystem. To explore ecological relationships amongst sympatric krill predators,we developed ecological nichemodels using amaximum entropy modeling approach (Maxent) that allows the integration of data collected by a variety of means (e.g. satellite-based locations and visual observations). We created spatially explicit probability distributions for the four krill predators in fall 2001 and 2002 in conjunctionwith a suite of environmental variables. We find areas within Marguerite Bay with high krill predator occurrence rates or biological hot spots. We find the modeled ecological niches for Adélie penguins and crabeater seals may be affected by their physiological needs to haul-out on substrate. Thus, their distributions may be less dictated by proximity to prey and more so by physical features that over time provide adequate access to prey.