Evidence gaps remain on the occurrence of bats in the offshore environment and their potential interactions with renewable developments.
Through a desk-based literature review, a review of existing data sets, and engagement with international projects through two online workshops this study presents cutting edge data and best practice.
Based on the data, Nathusius’ pipistrelle are the most commonly recorded species offshore and are considered a regular migrant to the British Isles. Surveys in the English Channel have recorded both common and soprano pipistrelle. There is some limited evidence to suggest that long distance migratory Nyctalus spp. such as N. noctula and N. leisleri may also migrate between the British Isles and Europe or Scandinavia.
Tagging, radio-tracking and acoustic surveys indicate that Nathusius’ movement across the Southern-North Sea peaks during the autumn (August to October) and spring (April to May) migration windows. Though exact routes are not known, migration can be linked to environmental variables such as wind speed and air temperature.
The report outlines the pros and cons of different monitoring techniques and mitigation methods, outlines existing and upcoming guidance and best practice, highlights remaining evidence gaps and includes recommendations for future work in this emerging field.