# How are bats affected by wind turbines?

Dead bats are found beneath wind turbines all over the world. It’s estimated that tens to hundreds of thousands die at wind turbines each year in North America alone.

Unfortunately, it’s not yet clear why this is happening. It’s possible that wind turbines interfere with seasonal migration and mating patterns in some species of bats. More than three quarters of the bat fatalities at wind turbines are from species known as “tree bats,” which tend to migrate long distances and roost in trees. These bats migrate and mate primarily during late summer and early autumn, which is also when the vast majority of bat fatalities at wind turbines occur. It’s also possible that bats mistake slow or stopped turbine blades for trees.

## Related Content

Filter Total Items: 7

### Where do bats live?

Bats can be found in almost all parts of the world and in most regions of the United States. In general, bats seek out a variety of daytime retreats such as caves, rock crevices, old buildings, bridges, mines, and trees. Different species require different roost sites. Some species, such as the Mexican free-tailed and gray bats live in large...

### Why is it important to know the locations of wind turbines?

No publicly-available, national database of wind turbines existed prior to the creation of the USGS Windfarm mapper, which was replaced with the U.S. Wind Turbine Database (USWTDB) in 2018. Knowing the location of individual turbines and their technical specifications creates new opportunities for research and improved siting and is important...

### Why are bats important?

By eating insects, bats save U.S. agriculture billions of dollars per year in pest control. Some studies have estimated that service to be worth over $3.7 billion per year, and possibly as much as$53 billion. This value does not, however, take into account the volume of insects eaten by bats in forest ecosystems and the degree to which that...

### Are bats dangerous?

All healthy bats try to avoid humans by taking flight and are not purposely aggressive. Most bats are about the size of a mouse and use their small teeth and weak jaws to grind up insects. You should avoid handling bats because several species, such as the hoary and big brown bats, have large teeth that can puncture skin if they are handled...

### What do bats eat?

Bats are the most significant predators of night-flying insects. There are at least 40 different kinds of bats in the U.S. that eat nothing but insects. A single little brown bat, which has a body no bigger than an adult human’s thumb, can eat 4 to 8 grams (the weight of about a grape or two) of insects each night. Although this may not sound like...

### Are bats blind?

No, bats are not blind. Bats have small eyes with very sensitive vision, which helps them see in conditions we might consider pitch black. They don’t have the sharp and colorful vision humans have, but they don’t need that. Think of bat vision as similar to a dark-adapted Mr. Magoo (a cartoon character with very poor vision). Learn more at the...

### What should I do if I find dead or dying bats, or if I observe bats with signs of White-nose Syndrome?

If you find a dead or dying bat: Contact your state wildlife agency, file an electronic report in those states that offer this service, e-mail U.S. Fish and Wildlife Service biologists in your area, or contact your nearest Fish and Wildlife Service field office to report your potential White-nose Syndrome (WNS) observations. It is important to...
Filter Total Items: 7
Date published: March 31, 2021

### New USGS Analysis of Wind Turbine Upgrades Shows No Impact on Wildlife Mortality

CORVALLIS, ORE. – Reduction in wildlife mortality rates is sometimes cited as a potential benefit to the replacement of older, smaller turbines by larger, next generation turbines. In contrast, others have expressed concern that newer, larger turbines may actually increase bird and bat deaths.

Date published: October 28, 2020

### Trick or Treat? The Frightening Threats to Bats

Date published: May 16, 2018

### Mapping the Nation's Wind Turbines

There are more than 57,000 wind turbines across the United States, and a new tool allows you to get up close and personal with each one!

Date published: April 19, 2018

### U.S. Geological Survey and U.S. Department of Energy Release Online Public Dataset and Viewer of U.S. Wind Turbine Locations and Characteristics

Today, the U.S. Geological Survey (USGS) and the U.S. Department of Energy (DOE), in partnership with DOE’s Lawrence Berkeley National Laboratory and the American Wind Energy Association, released the United States Wind Turbine Database (USWTDB) and the USWTDB Viewer to access this new public dataset.

Date published: January 17, 2017

### A Deadly Double Punch: Together, Turbines and Disease Jeopardize Endangered Bats

Date published: January 10, 2017

### Advancing Wind Energy and Avoiding Wildlife Conflicts

Our Nation works to advance renewable energy and to avoid conflicts with and conserve wildlife.

Date published: September 29, 2014

### Wind Turbine or Tree? Certain Bats Might Not Know

Certain bats may be approaching wind turbines after mistaking them for trees, according to a study published in the Proceedings of the National Academy of Sciences.

Filter Total Items: 23
September 26, 2019

### PubTalk 09/2019 — Bats in the West

Title: Bats in the West: Discoveries, Questions, and Future Research
By Gabriel A. Reyes, USGS Biologist

• Learn about bat ecology, diversity, and the role they play in our ecosystem.
• See how scientists are using a variety of methods including capture, acoustic monitoring, and tracking, to learn more about local bat species.
• Find out how
August 1, 2018

### Pallid bat with transmitter

A Pallid bat (Antrozous pallidus) is outfitted with a radio transmitter to help lead us to its roost. The transmitter is attached with a temporary adhesive that will wear off within around 2 weeks, about as long as the battery life of the transmitter lasts. By following the bat USGS researchers will be able to learn what habitat types are important for this species,

...
October 16, 2017

### Western red bat release

Like most wild animals, bats often don't appreciate being handled for research purposes. However when holding bats after handling and examination, they often appreciate the warmth and need a little push to go. This Western red bat (Lasiurus blossevillii) was captured during USGS WERC research to learn more about the ecology, distribution, and movement patterns of

...
January 26, 2017

Wind turbines

January 26, 2017

### A Bat Interacting with a Wind Turbine

Surveillance video from a temperature-imaging camera shows a bat interacting with a wind turbine. Video credit: Paul Cryan, USGS

December 15, 2016

### Spectrograph of an acoustic bat recording

Spectrograph of an acoustic recording from the western small-footed myotis (Myotis ciliolabrum) noting shape and frequency of call with photo of the western small-footed myotis and cartoon representation of this bat echolocating below.

August 19, 2016

### Wind Turbines and Rainbow

Tall wind turbines in a semi-arid shrubland with a bright rainbow

August 19, 2016

### Scanning Electron Microscopy of Pallas’ Mastiff Bat

Scanning Electron Microscopy of Pallas’ Mastiff Bat, Molossus molossus

June 10, 2016

April 11, 2016

### Thermal image of bat flying behind wind turbine

December 31, 2014

### Bat emergence, Paul Cryan, USGS photo.

Bats emerging from the trees in the early evening sky.

December 31, 2013

### A bat that was killed by a wind turbine laying in the grass.

A bat that was killed by a wind turbine laying in the grass.