It's not an unusual sight out in the ocean: blue whales ​slurping up clouds of krill. But researchers most often have a boat's eye view for this event. Now new drone footage from Oregon State University is giving them a whole new perspective on how these massive creatures, the largest animals on the planet, catch their dinner.

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It takes a lot of energy for the 100-foot animal, which can weigh up to 200 tons, to get up to cruising speed, Leigh Torres, a marine spatial ecologist at Oregon State, explains in the video. Opening its mouth can slow it down significantly, so the creature has to decide on the fly whether a krill cloud is substantial enough to be worth the effort.

Whales filters the krill through its baleen plates while plowing through a large krill cloud. And the video shows one whale doing just that. “Here we see the animal recognize that there’s a big krill patch," Torres says in the video. "He ... turns on his side, pumps his flukes, opens his mouth and lunges right for it. It’s just an amazing sequence of events.” But later, when it encounters a smaller cloud, the creature turns its head as if he was beginning the process again before deciding it wasn't worth it.

As Nick Visser reports for the Huffington Post, blue whales have been on the endangered species list since 1964, after generations of whaling depleted their numbers by 70 to 90 percent. The whale populations have been on the rise since then, reaching 97 percent of their historic levels in California. But they still face many threats—especially oil and gas development, ship strikes and pollution.

“Amongst all of that activity, these animals need to be able to find their food and feed efficiently,” Torres says. “So the more we know about how they’re finding food and what makes good food for them, it will help us be able to manage their population and make sure that human activities aren’t impacting them too much.”

This isn’t the first time researchers have used drones to study blue whales. Scientists with the Ocean Alliance began have previously used drones dubbed SnotBots to capture mucus from the spray that spurts from the whale’s blowhole, giving them a nice photo of the whale along with DNA, microbe samples as well as stress and pregnancy hormones.