The gray whales have been migrating from Mexico to Alaska. The area near Monterey Bay in Northern California is ideal for a killer whale ambush, according to wildlife biologist Bernardo Alps.
"There's a very deep canyon that crosses the bay and comes really close to shore so the migrating gray whales have to cross deep water, which killer whales prefer for an attack," Alps explained.
In the video player above, Alps details how the gray whales attempt to protect their calves from the killer whales.