Dodging the blades: new insights into three-dimensional space use of offshore wind farms by lesser black-backed gulls Larus fuscus

Abstract

GPS telemetry is improving our understanding of the way animals interact with their environment. Recent research has used this technology to assess the impact of offshore wind farms (OWFs) on seabirds, but few studies have collected fine-scale data from birds flying within OWFs. We use GPS telemetry to investigate movements of lesser black-backed gulls Larus fuscus in relation to OWFs from a protected site with an active breeding colony. Individual birds varied considerably in their use of OWFs; 15 out of 24 birds visited them, and time spent in these areas was 1.3% of time budgets across all birds. Two birds, for which the most data was collected, frequently entered OWFs and flew at turbine blade height; however, their overlap with the spherical 3-dimensional rotor swept volume was significantly lower than a random distribution. Although preliminary, these tracking data suggest a lack of a macro-scale (wind farm-scale) avoidance for L. fuscus but a potential meso-scale (within wind farm-scale) avoidance of turbines. Such data are therefore important in improving our understanding of the implications of OWFs for seabirds.