Bat Populations – Stewards of Texas

Impacts to Texas Bat Populations

Texas has the largest bat colony in the world in San Antonio’s Bracken Cave Preserve with nearly 20 million bats. Other famous sites such as Austin’s Congress Avenue Bridge and Fredericksburg Old Tunnel State Park draw tourists from across the world. 32 of the 47 bat species found in the United States call Texas home as well.

Bats are an important part of our ecosystem, pollinating our plants and controlling mosquito populations. A study by leading bat researchers showed that bats save farmers $12 to $172 per acre in pest control costs nationally each year. In Texas alone, they estimate that bats saved $1.4 billion by eating crop pests.

Wind turbines are negatively impacting Texas’ native bat populations, but data is limited and mostly exists only in national studies or other areas around the world.

Collision Fatalities

According to Bat Conservation International, collisions with wind energy turbines are one of the leading causes of bat mortality in North America and Europe. In one year alone, it was estimated 600,000-900,000 bat fatalities occurred from wind turbines in the United States. Here in Texas, wind turbines kill about 200,000 bats each year.

Habitat Displacement

The construction and operation of wind turbines result in habitat loss and changes in bat activity. Research found that when wind turbines were placed close to existing roosts, bats hunted around the turbines and suffered casualties. When wind turbines were placed further from roosts, the bats avoided the area, leading to a loss of habitat.

Limited Populations

Bats are slow to reproduce, so population decline is difficult to recover from. The cumulative effects of increased mortality from wind turbines could lead to significant declines in bat populations over time.