Do Wind Turbines Kill Birds? A Data-Driven Answer

Short answer: yes, but the full story matters

Yes, wind turbines do kill birds. But they cause a small share of bird deaths compared with other dangers.

The bigger concern is which birds are affected and where turbines are built. Studies of land-based projects find about 3–6 bird deaths per megawatt (MW) per year—so a 100 MW wind farm may average roughly 300–600 bird deaths annually (research summary). Careful siting and smart operations can lower that number further while still providing clean power.

Context also matters. Climate change and habitat loss remain much bigger threats to birds than wind power. As one overview notes, windmills account for only about 0.01% of cat-related bird deaths (University of Michigan).

Why the “cats vs. windmills” comparison is misleading

It compares totals, not impact on species

Comparing total deaths misses which birds are harmed. Cats often kill small songbirds like finches and robins. Wind turbines more often affect large, soaring birds (eagles, vultures) and some migrating species that fly at rotor height (Yale Environment 360). These larger birds tend to fly while watching the ground for food, not looking ahead, which raises collision risk.

Conservation status matters

Some raptors have slower reproduction and smaller populations. A few losses can mean more for these species than for abundant songbirds. That’s why experts warn that saying “cats kill more” is not a good argument to dismiss wind impacts (PBS SoCal; American Bird Conservancy).

How many birds do wind farms kill? The data

• Typical range: About 3–6 birds per MW per year at onshore wind farms, after adjusting for detection and search bias (REWI/AWWI 2021 summary).
• Project example: A 200 MW wind farm might see about 600–1,200 birds per year on average. Good siting can reduce this.
• Relative share: Some estimates suggest wind accounts for less than 1 in 4,000 bird deaths overall, a very small fraction compared with other causes (Ørsted summary). Note: that figure is a rough, global share and should be read alongside independent science.

Design and siting have improved over time. Taller towers, slower-rotating blades, better layouts, and pre-construction wildlife studies have reduced impacts (U.S. Department of Energy).

Important nuance: Early projects in the 1980s, especially in a few high-raptor areas, had higher raptor deaths (The Guardian). Lessons from those sites helped shape today’s best practices.

Avian mortality sources compared (big picture)

Source	Relative scale	Species most affected	Conservation impact	Notes / sources
Outdoor cats	Very high	Mostly small songbirds	High local impacts on some species	UMich overview; Columbia Climate
Window collisions	Very high	Many migratory songbirds	Broad, widespread effects	Yale Environment 360
Habitat loss & climate change	Very high	Across many groups	Long-term population declines	UMich
Wind turbines	Small share	Some raptors; some migrants	Site- and species-specific	REWI/AWWI 2021; DOE; Yale
Offshore wind (current data)	Small share (monitored sites)	Varies by region and season	Still being studied	Ørsted; DOE

Which birds are most at risk near wind farms?

• Large soaring birds (raptors): Eagles and vultures spend time flying at heights where blades turn, often scanning the ground for food and not looking ahead (Yale Environment 360).
• Migratory songbirds: Some fly at night and may pass through rotor height during certain weather patterns. Risk varies by route and season (DOE).
• Site-specific species: When projects sit along busy flyways or near nesting/foraging areas, risk goes up. That is why local studies are key (REWI/AWWI).

“Window collisions and cats kill more birds than wind farms do, but turbine impacts must be taken seriously.” — Yale Environment 360

What makes wind safer for birds? Proven steps

1) Smarter siting

Developers now use mapping, field surveys, and tracking data to avoid high-use bird areas. Tools like radio-frequency tags and transmitters help show where birds fly and feed, guiding site choices (DOE WINDExchange).

2) Better operations (smart curtailment)

Operators can slow or stop turbines during high-risk moments—such as peak raptor activity or mass migration at night. In some places, human observers even pause single turbines when at-risk birds approach (Yale).

3) Detection technology

Camera, radar, and acoustic systems help spot birds and trigger responses. This is part of a broader toolbox to cut risk while keeping energy flowing (DOE).

4) Turbine design and layout

Modern turbines have different spacing and rotor speeds than early projects. That, plus careful layout, reduces risky areas and makes it easier to avoid key habitats (DOE).

5) Offshore monitoring

Offshore projects use tracking, radar, and tailored siting. Some sites have recorded very few bird deaths over multi-year periods, though research continues as projects scale (Ørsted summary; DOE).

A quick note on bats

Bats are often more affected than birds at some wind sites. Adjusted bat fatality rates can range from 4–7 bats per MW per year, with some ridge-top projects reporting higher numbers. Raising “cut-in” wind speeds (when blades start turning) during high bat activity can reduce fatalities (REWI/AWWI 2020).

What this means for communities and students

• If you are evaluating a project: Ask for the wildlife study, siting maps, and the bird and bat protection plan. Look for smart curtailment and monitoring commitments (DOE).
• If you are doing a school project: Explain both the quantity and the quality of impacts. Note that wind’s share of deaths is small, but certain species need special care (ABC Birds).
• If you are debating online: Share data, but also highlight solutions—better siting, detection tech, and curtailment. This shifts the conversation from blame to fixes (Yale).

FAQs

Do wind turbines kill birds at sea?

Some offshore sites report very few bird deaths so far, but monitoring continues as more projects are built. Impacts vary by region, migration paths, and season (Ørsted summary; DOE).

Are new turbines safer than old ones?

Generally, yes. Modern siting tools, layouts, and operations have reduced risk compared with early projects (DOE).

Why not just say “cats kill more” and move on?

Because conservation impact is about which species are affected and how that changes populations. Large raptors and some migrants may be more sensitive to losses. So wind projects must plan and operate with care (PBS SoCal; ABC Birds).

Bottom line

Wind turbines do kill birds, but they account for a small fraction of total bird deaths. The key is to lower risk where it matters most—protecting at-risk species and high-use habitats. With strong siting, smart tech, and responsive operations, wind energy can stay a climate solution and get safer for wildlife (DOE; REWI/AWWI).