A group of killer whale mothers and calves were seen feasting over the course of four days last week and over the weekend on the carcasses of two dead gray whales just off the Monterey Coast. Drone footage by Monterey Bay Whale Watch captured the feast on Sunday, and a rep for the group, Nancy Black, tells NBC Bay Area that this type of group behavior so close to the coast is "pretty rare."

The killer whales have been feasting on the remains of the dead whales since Thursday, and some humpback whales also got in on the action as the killer whales swarmed in such a large number.

This is whale migration season right now, as whales of multiple species work their way up the Pacific coast toward Alaska where they'll feed for the summer, and last spring saw multiple dramatic whale sightings in and around San Francisco Bay, including several humpbacks which do not typically tend to enter the Bay at all.