But that doesn't faze the local orcas, which have become skilled at hunting and killing the whales.

For the first time, scientists have witnessed, thanks to drone video, how the predators work as a team to surround and kill a juvenile bowhead, which can be three times heavier than an adult orca. (Read how orcas work together to whip up a meal.)

“We’ve known for a long time that orcas can hunt grey and bowhead whale calves by separating them from their mothers, but it’s interesting that here they kill a bowhead aged between one and five years old," says Olga Shpak, a biologist at the Severtsov Institute of Ecology in Russia who saw the hunt firsthand. The juvenile