Integrating Measures of Animal Movements to Estimate the Winter Distribution of Two Penguin Species
AbstractAnimal migration is a widespread phenomenon that has both ecological and evolutionary significance. However, due to the inherent logistical challenges of tracking animals over large distances in the marine environment, remarkably little is known about migration, dispersal, and migratory connectivity of marine organisms. This lack of information presents a critical knowledge gap for managers seeking to define spatial and temporal management priorities for many wide-ranging marine animals of conservation concern. The objective of this proposal is develop and test a novel method of identifying the migration patterns and at-sea distribution of marine organisms by integrating both direct (geolocation tracking) and indirect (stable isotope analysis) measures of animal movements. We focus this proposal on two, wide-ranging marine predators, the Adélie (Pygoscelis adeliae) and chinstrap penguin (P. antarctica). We will first identify the migratory movements and winter foraging areas of 57 individual penguins using recovered archival geolocation tags. Next, we will use bulk and compound-specific SIA of penguin tail feathers to identify the isotopic signatures of geographically discreet winter foraging areas used by these tracked individuals. Last, we will “scale up” this analysis region-wide by assigning non-tracked penguins sampled from multiple breeding colonies in the Antarctic Peninsula to specific over-wintering areas based on their isotopic signatures. This study will provide a first ever, regional-scale analyses of the winter movements and distributions of the dominate avifauna species in Antarctica and allow us to develop and explore new questions about how migratory behaviors influences resiliency to recent climate change. In addition, this proposal will form the basis of an NSF proposal and serve as a template for future studies of animal migration in other ocean megafauna species.