The Washington Post article

A mystery of flight is how animals keep from getting discombobulated and ankles-over-elbows as they swoosh around and interact with their environment. For example, scientists wanted to know how flying animals regain stability -- or "arrest the yaw" -- after initiating a turn.

The answer turned out to be surprisingly simple. First, the animal initiates the turn with asymmetrical flapping.

Then, rather than stopping the turn with a reverse asymmetrical flapping, the animal switches to regular symmetrical flapping. At that point, natural aerodynamics kick in.

"There's a simple rule for slowing back down: It's going back to being symmetric. You don't have to try anything special," said Hedrick. "What we have here is a shortcut rule for stability."