Tracking a small seabird: First records of foraging behaviour in the Sooty Tern Onychoprion fuscatus
Over the last 12 years, the use of global positioning system (GPS) technology to track the movements of seabirds has revealed important information on their behaviour and ecology that has greatly aided in their conservation. To date, the main limiting factor in the tracking of seabirds has been the size of loggers, restricting their use to medium-sized or larger seabird species only. This study reports on the GPS tracking of a small seabird, the Sooty Tern Onychoprion fuscatus, from the globally important population breeding on Dog Island, Anguilla. The eight Sooty Terns tracked in this preliminary study foraged a mean maximum distance of 94 (SE 12) km from the breeding colony, with a mean trip duration of 12 h 35 min, and mean travel speed of 14.8 (SE 1.2) km/h. While our study was limited in scope, it showed that small loggers such as the ones used present new opportunities for accurately tracking the short-term movements of small seabird species, thus providing huge potential to advance our understanding of seabird behaviour and conservation. Indeed, all study birds foraged in waters outside of Anguilla’s Exclusive Economic Zone near the neighbouring islands of Saint Martin, Saint Barthelemy, Saint Eustatius, and St Kitts and Nevis, with 50% of birds commuting along the same route, thus demonstrating that the conservation of this population, with further study, will have geopolitical complexities.
Keywords: Anguilla, Caribbean, GPS tracking, Lesser Antilles, tropical seabird, Sooty Tern