This is Bird Note.

Looking out at the ocean, we might just see a chaos of waves and troughs.

But, like an expert angler, a turn can read the surface of the water to find where to catch its next fish.

Researchers studying the feeding habits of turns piloted a drone to learn how the birds zero in on good fishing spots.

By flying the drone at an altitude of 100 meters, well above the feeding turns, the scientists got a detailed

look at the bird's flight pads without disturbing them from the hunt. The flight paths showed

that the turns seek out turbulent water. They tend to dive for fish where colliding currents

form a vortex. The swirling water traps small fish near the surface, the perfect place for turns

to snatch him up. When the turn spot new bubbly upwelling at a distance, they fly to them

as the rising currents can bring other prey animals along for the ride. Using drones to observe

airborne birds from a safe distance

is helping reveal how they see the world.

For the turns, the water's surface isn't just nice to look at.

It's a map to their next meal.

For Bird Note, I'm Mary McCann.