An experimental study of the at-sea movement of a small diving seabird and the biological and ethical implications of wildlife tracking research

Abstract

Year-round ecology and behaviour of seabirds is poorly understood due to difficulties associated with measuring at-sea activity during the non-breeding season. Lightweight biologging devices permit the tracking of individual movement across seasons and periods of the breeding cycle. To examine at-sea distribution of small diving seabirds, I deployed tarsus-mounted geolocators (<1.1 % body mass) on 31 Crested Auklets (Aethia cristatella) in 2011, at a breeding site at Buldir Island, Alaska. I recovered ten of these geolocators in 2012 (three provided usable data), revealing for the first time, an unexpected long-distance migration with substantial habitat overlap among individuals. I also experimentally quantified effects of devices on individuals’ behaviour to evaluate biological and ethical relevance of research. Deleterious effects were detected on chick condition, provisioning rates and social activity, with greatest impacts on return rates. To maintain the rigor required by basic scientific principles, wildlife tracking studies must quantify effects of attached devices and consider the biological relevance of the resulting measurement data concerning the behaviour of interest.