When it comes to generating green energy from the wind, Texas leads the way.

But in the pursuit of cleaner energy, there's also an environmental cost: Dead birds and bats killed by turbine blades.

Now a unique research project in North Texas is trying to find out how many are dying and what can be done to save them.

As Texas continues to flip the switch from dirty coal to clean wind, not all is perfectly green.

That's why Texas Christian University researchers are scanning the base of a wind turbine at Wolf Ridge, outside Muenster, Texas.

"Some of them are obvious that the turbine killed them. Other times you can't tell," said field technician Jennifer Ellis of the dead birds she finds.

Among them are raptors, vultures, yellow-billed cuckoos, said Amanda Hale, TCU researcher.

Birds killed by wind turbines pale in comparison to birds killed by cars, buildings and other animals.

"We do know that birds and bats are being affected by wind turbines," said Hale.

Hale and her team want to definitively determine how many birds and bats are killed by wind turbines.

Her peer-reviewed research project is funded by the nation's biggest renewable energy company NexTera.

"We've actually seen a huge variety of birds," Hale said.

But it turns out, dead bats are the surprise finding.

Hale did not expect to find any. Instead, her team has found five times more bats than birds.

Why is that a problem?

The bat population is smaller, more susceptible to disease, and slower to reproduce.

"If we add wind on top of it, it's enough to be a real concern," said Hale.

Back at the Hale's laborartory at TCU, they carry out tests.

"We can measure how good we are at finding these bats," said Kris Karsten.

Hale's team analyzes DNA, weather patterns and mortality trends at the Wolf Ridge Wind Farm, all for one purpose.

"If we can predict when mortality happens, we can use that information to prevent it," said Hale.

As our reliance on wind energy grows, a discovery like that may keep us from making things worse, while we're trying to make them better.