Increasing evidence that bats actively forage at wind turbines

Area of Science:

• Wildlife Ecology
• Acoustic Monitoring
• Molecular Ecology

Background:

• Bat fatalities at wind farms are a significant conservation concern.
• The precise reasons for bat attraction to turbines remain unclear, with foraging being a key hypothesis.
• Understanding bat behavior around turbines is crucial for developing effective mitigation strategies.

Purpose of the Study:

• To investigate the role of foraging activity in bat fatalities at wind turbines.
• To determine if bats prey on insects found at wind turbine sites.
• To assess the diet composition of bats found at a wind farm.

Main Methods:

• Conducted acoustic monitoring to detect bat foraging activity near turbine towers.
• Performed insect surveys to quantify insect abundance and types around turbines.
• Utilized DNA barcoding of stomach contents and fecal pellets from bat carcasses and live bats to analyze diet.

Main Results:

• Acoustic monitoring confirmed foraging activity by six bat species near turbine towers.
• Insect surveys revealed consistent high proportions of Lepidoptera, Coleoptera, and Orthoptera around turbines.
• Diet analysis showed bats consumed insects abundant at turbine sites, with full stomachs indicating foraging at the time of death.

Conclusions:

• Bats actively forage around wind turbines, attracted by insect availability.
• The study provides strong evidence that foraging behavior contributes to bat fatalities.
• Mitigation measures to reduce bat mortality at wind facilities should be widely implemented.