Meeting Abstract

1.2  Friday, Jan. 4  A Bioenergetics Approach to Understanding the Population Consequences of Natural and Anthropogenic Disturbance COSTA, D.P.*; SCHWARZ, L.K.; MARESH, J.; ROBINSON, P.W.; CROCKER, D.E.; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Univ. of California, Santa Cruz; Sonoma State University costa@ucsc.edu

A major hurdle with marine mammal conservation and management is to know if and when measurable short term responses result in biologically meaningful changes in populations. We have been measuring the behavioral and energetic response of pinnipeds to environmental variations such as ENSO events, which cause reductions in prey availability, to assess their ability to accommodate to changing conditions. The ability of animals to respond to natural perturbations can be used to estimate their response to anthropogenic disturbance. Pinnipeds offer a unique system to study this question; there are extensive data on their reproductive and foraging energetics that can be coupled with their reproductive success. Long term demographic data exist that can be used to infer population consequences. Finally, they exhibit a diverse range of life history patterns from income breeders to capital breeders. First we consider whether there is a difference in the ability of capital and income breeders to accommodate to environmental perturbation. Second using northern elephant seals we integrate these bioenergetic measures to examine the coupling between short term reductions in foraging success to reproductive success and whether and when this results in a population level effect.