Figure. A field of wind turbines.
Alberta's strong and steady winds provide an ideal opportunity for harnessing wind energy through the installation of wind turbines. Currently, one-third of Alberta's land base is utilized for wind turbines, positioning Alberta as a leading province in wind power, alongside Quebec and Ontario. The province has a rich history in wind energy development, with the first wind turbine established in 1933 as part of the Cowley North project near Pincher Creek. Today, the Whitla Wind project stands as the largest wind turbine farm in Alberta, contributing significantly to the province's renewable energy portfolio. Despite the benefits of clean, renewable, and green energy, wind turbines pose a significant challenge to wildlife, particularly bats.
Wind turbines have a considerable impact on bat populations, especially migratory bats. Many bat species are endangered or threatened, and one of the reasons is due to interactions with wind turbines. During their autumn migration to find warmer regions, bats often fly past wind turbine fields. Contrary to common misconceptions, it is not the turbine blades that injure the bats but a different factor. Wind turbines create pockets of negative air pressure, which suck in air. When bats fly near these turbines, the negative air pressure can injure their lungs due to rapid decompression, leading to their death either from the fall or from asphyxiation. This phenomenon, known as barotrauma, is particularly devastating because it is invisible and often goes unnoticed until the bats are found dead on the ground. In Canada and the US, it's estimated that tens to hundreds of thousands of bats die each year due to this phenomenon (Florent & Bennett, 2024). Thus, the impact of wind turbines on bats is a pressing concern for conservationists and scientists.
On September 7th, 2023, an injured adult male silver-haired bat was found in Medicine Hat, having been harmed by a wind turbine. Upon examination, our team found the bat had a left-wing tear and traces of blood in its urine. The team applied a clear medical dressing to facilitate healing and administered anti-inflammatory medication. The chest and shoulder area were wrinkled and crusty and his belly was bald. After regular treatments in our bat hospital, including the use of humidifiers and moisturizing, new fur growth occurred. Unfortunately, his condition started to declined and he died in our care. This case highlights the severe impact of wind turbines on bats and underscores the need for effective mitigation strategies.
Figure 2. Adult male silver-haired bat wing injury.
Migrating bats start their journeys from late August to September. However, the journey through wind turbine fields poses a significant risk, especially to weaker, independent young bats. Both adults and juveniles migrate together. Migration is a critical period for bats, as they rely on stored energy reserves to complete their journey. The additional stress of avoiding wind turbines can deplete these reserves, making survival even more challenging.
The factor of landscape homogenization and wind turbines negatively impact bat activity (Sotillo et al., 2024). Additionally, bats often chase high-flying insects around turbines, making them vulnerable to rotor speed, pitch, and noise. Factors such as body size, flight behaviour, visual acuity, and prey availability also play a role in bat-turbine interactions (Garvin et al., 2024). The placement of wind turbines in key migratory routes and habitats can disrupt feeding and roosting patterns, further endangering bat populations. Planners are seeking ways to promote the use of green renewable energy with wind turbines while minimizing disruptions to the ecosystem (Florent & Bennett, 2024). Scientists continue to study these interactions and their long-term effects on bat populations. Research is focused on developing technologies and strategies to reduce bat mortality, such as ultrasonic deterrents, curtailing turbine operations during peak migration times, and designing bat-friendly wind farm layouts.
Public awareness and education are crucial in addressing the impact of wind turbines on bats. Understanding the ecological importance of bats and the threats they face can drive support for conservation efforts. Bats play a vital role in controlling insect populations and pollinating plants, contributing to ecosystem health and agricultural productivity. Protecting bat populations from wind turbine-related mortality is essential for maintaining these ecological functions.
If you come across a bat that has fallen after passing a wind turbine and is still alive, please contact the us at (403) 214-1312 or your nearest certified wildlife rehabilitation centre . By working together, we can find solutions that balance the need for renewable energy and the preservation of wildlife.
References
Florent, S. N., & Bennett, E. M. (2024). Wind turbines kill bats, but they don't have to. Austral Ecology, 49(2), e13495.
Garvin, J. C., Simonis, J. L., & Taylor, J. L. (2024). Does size matter? Investigation of the effect of wind turbine size on bird and bat mortality. Biological Conservation, 291, 110474.
Sotillo, A., le Viol, I., Barré, K., Bas, Y., & Kerbiriou, C. (2024). Context-dependent effects of wind turbines on bats in rural landscapes. Biological Conservation, 295, 110647.
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