Humpbacks trying to fight off killer whale feeding frenzy

A pod of killer whales have killed seven whales in 12 days in Monterey Bay, but the humpback whales in the area appear to be doing just about everything they can to stop the feeding frenzy.

SFGATE reported last week on the killer whales' unprecedented string of attacks on gray whales, which are migrating through the Monterey Bay on their way from Mexico to Alaska. The back-to-back killings have certainly drawn attention. But as San Francisco Chronicle outdoors writer Tom Stienstra pointed out in his most recent column, the involvement of humpback whales in these interactions has been largely overlooked.

Nancy Black, a marine biologist with Monterey Bay Whale Watch, explained that humpback whales have come to Monterey Bay a few weeks earlier than usual this year. Black estimates there are about 60 or 70 in the area right now. Their early arrival means they're around to witness the orcas' hunting season.

And the humpbacks don't seem content to eat anchovies and mind their own business.

"Humpbacks like to interfere with the killer whales for some strange reason," Black told SFGATE. "They seem to want to protect the prey."

Photographers snapped some amazing pictures of killer whales and humpbacks while watching off the coast of Monterey, Calif. in April 2017. Photographers snapped some amazing pictures of killer whales and humpbacks while watching off the coast of Monterey, Calif. in April 2017. Photo: Daniel Bianchetta/Monterey Bay Whale Watch Photo: Daniel Bianchetta/Monterey Bay Whale Watch Image 1 of / 44 Caption Close Humpbacks trying to fight off killer whale feeding frenzy 1 / 44 Back to Gallery

In recent weeks, humpback whales have repeatedly charged over to the site of the kill and tried to deter killer whales from either hunting or feeding. Black said she has seen the humpbacks approach in groups of two or three and trumpet loudly to try and disperse the orcas.

Monday, a pair of humpbacks tried to use their flukes to push a pod of killer whales away from a feeding site (as seen in the drone video above).

"Every time the killer whales have been feeding, the humpbacks have been charging in," said Black. "Every single time."

Humpback whales have a long history of interfering with killer whales' hunting habits, but researchers still aren't exactly sure why they do it. Humpback whales don't have many natural predators. In fact, killer whales are some of the only animals who prey on young humpbacks. Black thinks the humpbacks may be fighting back against the orcas out of instinct, even though in these cases, they're not the ones being hunted.

As for those who think the humpbacks are behaving altruistically out of a desire to help gray whales, Black said, "It would be hard to believe they're doing it for that reason, but we don't know for sure."

While Black hasn't seen the humpbacks successfully prevent a killer whale attack in Monterey Bay over the past few weeks, a mother gray whale was able to save her calf from predation Sunday. Monterey Bay Whale Watch caught the encounter on drone video.

MORE VIDEO: Mother gray whale protects calf from killer whales

"The mother took her calf, held her breath and made a run for the beach," Black told SFGATE. The mother held her breath for seven minutes and the pair escaped the pod of predators, albeit a little bloody and battered.

The heightened activity in recent weeks has translated into amazing whale watching for those in Monterey Bay.

"This has never happened in my 30 years," Black said. "Just to witness that out in nature when you usually see that kind of thing on television is really spectacular."