Orcas aren’t just in the news lately for attacking boats. In May, a whale-watching tour by the Farallon Islands experienced something rare: a sighting of 20 orcas (or killer whales). Then, just last week, many of those same orcas, plus a few new ones, were spotted by Monterey in an even bigger group of over 30.
“They were socializing, playing, very playful,” said Nancy Black, founder of the California Killer Whale Project. It was like a giant family gathering: Orcas typically travel in smaller family groups of two to seven whales, but multiple families will meet up for hunting or, in this case, fun. Black, who has been studying orcas near Monterey for 30 years, said that sightings that large are incredibly rare. But it’s been oddly frequent in recent weeks.
Why are we seeing so many orcas right now?
It’s mostly luck, said Black.
“We don’t get to see them all that often,” said Michael Pierson of the Oceanic Society, who was leading the boat tour that spotted the first group of orcas out near the Farallons. He’ll see orcas near San Francisco maybe two or three times per year, he said, all out by the Farallons.
Near Monterey, it happens more frequently, because of the topography of the ocean, and whale migration and hunting patterns.
Orcas tend to stay in deeper water. Different orca families range from Baja all the way up to Alaska, but Black said the 120 orcas around Monterey and the Bay Area tend to move constantly from Southern California to British Columbia. However, they’re all mostly swimming out at the edge of the continental shelf. A quick look at a coastal ocean depth map will show that the shallow water around San Francisco extends about 26 miles, past the Farallon Islands.
But down by Monterey there’s something called the Monterey Canyon. It’s one of the deepest ocean canyons on the West Coast, starting near Moss Landing and extending out across Monterey Bay.
There are a few types of orcas. The transient orcas, which feed on mammals, tend to prey on seals, sea lions, sea otters, porpoises and also baby whales from other species. That means orcas hunt during sea lion and seal pupping season, which is happening right now at the Farallon Islands, said Pierson — and could explain some of the higher level of activity there.
They also hunt during humpback and gray whale migration season. The humpbacks and gray whales stay close to shore, in shallower water, to protect their babies. Where they need to cross the deep water channel, or get near the deep water in Monterey Bay, orcas can pick off their babies. That’s also happening right now. (Because of this, humpbacks really don’t like orcas; they have even been known to save other animals, like seals, from orcas.)

