Abstract
In this report we present the results of a statistical analysis applied on data on Common Guillemots (Uria aalge) from various European offshore wind farms. Results for the Princess Amalia Wind Farm (PAWP) show that there are clear spatial patterns in the distribution of birds. However, these spatial patterns differ per survey and there is no consistent pattern in these spatial distributions. We were not able to detect a significant effect of the wind farm on these spatial distributions. Results for the Windpark Egmond aan Zee (OWEZ) are similar. Results for Robin Rigg showed that spatial patterns also differ per survey. However, there seems to be a (weak) wind farm avoidance effect in the spatial patterns for Robin Rigg. The analysis of PAWP, OWEZ and Robin Rigg data indicate that spatial patterns in abundances differ per survey. The data from the Alpha Ventus, Blighbank en Thorntonbank, Horns Rev and Sheringham Shoal Offshore wind farms do not allow for the analysis of individual surveys due to the large number of zeros for Guillemots. Analysis of combined surveys may be misleading. Given the fact that for three wind parks, spatial patterns differ per survey, and for all other wind farms considered in this report we cannot analyse data per survey, it may be an option to focus future research on a different species, or base the analyses on multiple species simultaneously.