Meeting Abstract

61.5  Jan. 7  To what extent does life-history affect space utilization in marine top-predators? TREMBLAY, Yann*; ROBINSON, Patrick W; SHAFFER, Scott A; KAPPES, Michelle A; MCDONALD, Birgitte I; CROCKER, Dan E; COSTA, Dan P; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Sonoma State University; Univ. of California, Santa Cruz tremblay@biology.ucsc.edu

Laysan albatrosses (Phoebastria immutabilis) and northern elephant seals (Mirounga angustirostris) are two top-predators that forage in the northern Pacific Ocean. Their diets overlap and both forage extensively within the transition zone. Tracking data from these species reveal that both exhibit area-restricted (ARS) patterns of movement, suggesting convergence in foraging strategies. However, these predators represent two extreme foraging modes. Albatrosses are fast moving, non-diving animals whereas elephant seals are slow but excellent divers. Using novel techniques for animal movement analysis, this work compares ARS behavior and spatial scale utilization between albatrosses and elephant seals to determine how space utilization is affected by fundamental life-history differences or limitations. Convergence in strategies was found for the smallest spatial scales whereas space utilization at large scales differed more. Duration and timing of the utilization of the different spatial scales were extremely different. Movements at small spatial scales are likely environment-dependant whereas movementsí patterns at large scales and time-use are most affected by the predatorís life-history.