Match between soaring modes of black kites and fine-scale distribution on updrafts

摘要

Understanding how soaring birds use updrafts at small spatial scales is important to identify ecologicalconstraints of movement, and may help to prevent conflicts between wind-energy development andthe conservation of wildlife. We combined high-frequency GPS animal tracking and fine-spatial-scaleuplift modelling to establish a link between flight behaviour of soaring birds and the distributionof updrafts. We caught 21 black kites (Milvus migrans) and GPS-tracked them while flying over theTarifa region, on the Spanish side of the Strait of Gibraltar. This region has a diverse topography andland cover, favouring a heterogeneous updraft spatial distribution. Bird tracks were segmented andclassified into flight modes from motion parameters. Thermal and orographic uplift velocities weremodelled from publically available remote-sensing and meteorological data. We found that birdsperform circular soaring in areas of higher predicted thermal uplift and linear soaring in areas of higherpredicted orographic uplift velocity. We show that updraft maps produced from publically available datacan be used to predict where soaring birds will concentrate their flight paths and how they will behavein flight. We recommend the use of this methodological approach to improve environmental impactassessments of new wind-energy installations