Activity Pattern and Correlation between Bat and Insect Abundance at Wind Turbines in South Sweden

Area of Science:

• Ecology
• Environmental Science
• Wildlife Biology

Background:

• Wind turbines can impact bat populations, with potential attraction due to foraging opportunities.
• Understanding bat activity patterns and species composition around wind turbines is crucial for conservation.

Purpose of the Study:

• To investigate bat species composition and activity at wind turbines in southern Sweden.
• To test the hypothesis that bats are attracted to wind turbines by insect availability.
• To analyze the influence of weather conditions and insect abundance on bat activity.

Main Methods:

• Bat activity was monitored over two years at three wind turbines using ultrasound recordings.
• Insect abundance was sampled at nacelle height using a suction trap.
• Meteorological data and different recording systems were compared.

Main Results:

• Bat activity showed high variation between nights and turbines.
• Unexpected bat species were recorded at nacelle height, alongside common open-air foragers.
• A weak positive correlation was found between bat activity and insect abundance.
• Bat activity was strongly correlated with weather conditions.

Conclusions:

• Insect abundance may not be the sole factor driving bat visits to wind turbines.
• Weather conditions significantly influence bat activity and pose challenges for collision mitigation strategies like curtailment.
• Further research is needed to refine mitigation measures based on a comprehensive understanding of bat behavior and environmental factors.