Wind turbines are spreading across Europe’s farmland as one of the most visible answers to climate change. But a new study from Germany suggests they may be quietly undermining one of nature’s own defenses against a warming world.
In the flat agricultural plains of Brandenburg, hundreds of small glacial ponds have long served as lifelines for bats — places to drink and hunt through the heat of summer. Now researchers are finding that something is keeping certain species away from the water’s edge. And the culprit may be the very machines built to cool the planet.
A solution with an unexpected side effect
Wind energy is one of the fastest-growing tools in the global fight against climate change. Governments across Europe and beyond are accelerating turbine construction to cut greenhouse gas emissions and move away from fossil fuels. The logic is straightforward: more turbines, cleaner electricity, a cooler future.
Researchers at the Leibniz Institute for Zoo and Wildlife Research (IZW) in Berlin wanted to know what that expansion means for wildlife — specifically for bats living in agricultural landscapes. Their study, published in Biological Conservation, focused on Brandenburg, a flat farming region in eastern Germany dotted with more than a thousand small glacial ponds known as kettle holes. What they found was a paradox few had anticipated: a climate solution that may quietly reduce certain species’ ability to cope with climate change itself.
Why water matters so much for bats
Bats are not the animals most people picture when they think about drought stress. But open bodies of water are essential to them — for drinking, and for hunting the insects that gather above the surface. Small, permanently filled ponds are especially valuable because they hold water even when surrounding wetlands go dry.
That reliability matters most in summer. Female bats are either pregnant or nursing during these months, placing enormous energy demands on their bodies, and heat stress compounds the challenge considerably. As climate change pushes summers hotter and drier, many seasonal waterholes are disappearing. Permanent ponds become refuges — not just useful, but critical.
July — the month the IZW team chose to study — sits at the tail end of the lactation period. Researcher Dr. Carolin Scholz describes it as “an energetically strenuous phase for female bats.” Losing reliable access to water at precisely this moment carries real consequences for survival and reproduction.
How the study was conducted
The research team placed acoustic detectors at 59 small ponds across northern Brandenburg — ponds selected because they hold water year-round, a key trait in a landscape where many summer waterholes go dry. Distances from the nearest wind turbine ranged from roughly 50 meters to 5,000 meters, allowing the team to map how bat behavior shifted across that gradient.
Data was collected only under similar weather conditions — no rain and moderate winds — to keep comparisons clean. Nearly 8,400 bat calls were recorded in total, then sorted into three functional categories: open space foragers, which hunt above fields and forest canopies; narrow space foragers, which hunt within dense vegetation; and edge space foragers, which prefer transition zones like forest margins.
Species recorded included noctule bats and house bats as open space hunters, mouse-eared bats and long-eared bats as narrow space hunters, and common pipistrelles, soprano pipistrelles, and western barbastelles as edge space foragers.
The numbers: how far bats stay away
The results were clear. As ponds moved closer to wind turbines, activity among open space foraging bats dropped by 53 percent. Narrow space foragers fell even further — down 63 percent. These were not minor fluctuations. They represented a substantial withdrawal from water sources those animals depend on.
Foraging behavior told a sharper story still. The acoustic signatures indicating active hunting — rapid, repetitive call sequences — declined by 87 percent for open space bats and 76 percent for narrow space bats as distance to a turbine shrank toward zero.
The avoidance did not stop at the turbine’s base. It extended across several kilometers, meaning turbines cast a behavioral shadow far beyond their physical footprint. Edge space foragers, including the common pipistrelle and western barbastelle, were the notable exception, showing no significant avoidance of turbine-adjacent ponds.
Navigating the ‘green-green conflict’
Prof. Christian Voigt, who led the research, describes the situation plainly: “There is a certain tragedy in these results, because a measure to mitigate climate change has the unfortunate side effect that certain bats are less able to cope with hot and dry summers.”
His team has spent years studying what they call the “green-green conflict” — the tension between expanding renewable energy and protecting wildlife. Bats are shielded under both German conservation law and EU legislation, yet they face direct deaths at turbine blades and now, as this study shows, indirect harm through habitat displacement. Two layers of legal protection, and still the pressure mounts.
Voigt’s recommendation is not to stop building turbines. It is to build them more carefully. Ecologically critical habitats — like the kettle hole landscapes of Brandenburg — should be given low priority as turbine sites, or excluded entirely.
That call for nuance points to something worth sitting with. The energy transition is necessary. But if the infrastructure designed to protect the planet ends up severing wildlife from the resources they need to survive a hotter world, then carbon accounting alone is not enough. Where we build matters just as much as how much we build — and answering that question requires looking well beyond the grid.
Carlos is an engineer with strong expertise in technical and industrial topics. He previously worked at international companies such as Siemens and speaks Spanish, German, English, and Italian.
