| Aerial imagery obtained from manned aircraft surveys is commonly used for monitoring colonial nesting waterbirds. Recent technological advances have spurred interest in the use of unmanned aircraft systems (UAS) for wildlife monitoring. UAS offer the ability to collect data at both high spatial and temporal resolutions while minimizing wildlife disturbance and observer safety risks. The potential advantages that UAS present depend on a number of factors including mission objectives, flight duration, sensor payload capacity, data processing workflows, and current regulatory requirements. In May 2015, we, in collaboration with the Pyramid Lake Paiute Tribe, set out to conduct UAS flights at Anaho Island National Wildlife Refuge in Nevada. We targeted American white pelicans (Pelecanus erythrorhynchos), double-crested cormorants (Phalacrocorax auritus), and California gulls (Larus californicus) to evaluate the utility of UAS for monitoring and informing the reproductive biology of colonial nesting waterbirds. By using fine-scale change detection with a multi-temporal nearest neighbor analysis, we were able to develop a rapid, accurate method to differentiate nesting from non-nesting individuals. Here, I will present the results of our work and discuss recommendations for planning and conducting colonial nesting waterbird surveys, and processing and evaluating the resulting imagery. |