Using distance sampling to understand how sea-going citizen scientists detect marine birds

Speaker: Michael Schrimpf, Cornell University 

Abstract: Ecotourists are increasingly crossing the open ocean on cruises, collecting citizen science data on seabirds as they do. These data can be useful for monitoring species distributions, but only if factors affecting the detection of birds from such ships are better understood. We partnered with the Antarctic expedition cruise industry to calibrate citizen science data from the eBird project (https://ebird.org/) by conducting concurrent distance sampling surveys aboard tour vessels. Our surveys measured factors that likely add bias to data collected by eBird volunteers, such as the observer’s vantage point and the tendency of birds to follow vessels. However, we also faced the challenge of distance sampling with fast-moving birds, and we are currently exploring simulations to help correct for this violation of distance sampling assumptions. Although this project is still ongoing, our preliminary results include several species-specific seasonal distribution patterns not previously described that are likely related to post-breeding dispersal. Our ultimate goal is for the data-rich, underused collection of at-sea eBird observations to aid in seabird monitoring and conservation efforts.