The violent hunting techniques of California killer whales, such as tail-slapping and head-butting, are revealed by scientists who studied a mysterious group of predators for 16 years.

Photo of author


  • Orcas use headbutts, tail slaps, and violent groupings against their prey.
  • Those who live in California’s Monterey Bay clearly have a favorite food: sea lions.
  • But their second favorite snack is seasonal migratory gray whale calves.
  • READ MORE: Whale watchers get Stunning close-up view of the orca hunt.

Orcas in Monterey Bay have been found to use violent hunting techniques to kill their prey, new research has revealed.

A team of scientists has been studying a specific group of these fearsome animals since 2006 and discovered that these whales feed on everything from sea lions and seabirds to elephant seals and gray whale calves, and use any method to devour their food.

Their hunting techniques included headbutting, tail strikes to stun, and even throwing their prey into the air.

Footage captured in the wild shows the top predators teaming up to separate a gray whale calf from its mother before killing and eating the calf and another captured orca by tossing a dolphin into the air like a rag doll.

The findings offer a rare glimpse into the world of this group of orcas, which primarily hunt mammals in the opening water and are not very well understood by scientists.

An orca chases a California sea lion. Sea lions made up almost half of this group of killer whales’ prey between 2006 and 2021.
A male killer whale slaps the water with his tail in an attempt to stun a young elephant seal.

Scientists found that the whales adapted their hunting behavior depending on whether they were sweeping open water or searching for prey in underwater canyons.

READ MORE: Living up to his ‘killer’ name!

Watch the “amazing” moment a killer whale individually kills and consumes a great white shark in just two minutes.

During the observed interactions of this event, at least two great white sharks died, as evidenced by the discovery of a second carcass measuring 3.55 meters (11.6 ft) nearby.

In open water, they spread out and moved erratically, possibly to cover more space and make it more difficult for their prey to predict their movements.

But in the canyon they moved stealthily and scientists suspect that they listen to the movement of the water to search for prey in this environment.

In recent years, orcas have gained enormous international attention for their coordinated attacks against other predators like sharks, and running similar attacks on ships.

Last March, for example, a terrified British couple watched helplessly as a pod of orcas rammed his sailboat again and againbreaking the rudder.

They also hunt alone, as was observed last month when a single orca killed a great white shark and they removed the liver, his favorite part of the shark, in less than two minutes.

In the new study, scientists found that orcas in Monterey Bay eat sea lions more often than any other prey, with the animals accounting for about 48 percent of their deaths.

One of the observations captured an orca stunning an elephant seal with a huge tail swipe.

Gray whale calves were the next most common prey, accounting for about 22 percent of orca deaths in Monterey Bay.

Third most common was the formidable elephant seal, which can weigh up to 9,000 pounds. This large mammal accounted for about 7 percent of their deaths.

An orca tosses a Pacific white-sided dolphin into the air. The whales often hunted these dolphins by coming in from below and pulling them out of the water.
An orca uses its teeth to grab the rostrum, or upper jaw, of an adult minke whale. Orcas often held their larger prey motionless while others attacked.

Harbor seals and common dolphins were next on the list, about six percent each. Occasional seabirds, the harbor porpoise, Pacific white-sided dolphin and Dall’s porpoise were the least common prey.

In addition to what the whales hunted, the researchers also looked for where they hunted.

They noted that Monterey Bay’s deep underwater canyon system appeared to provide a lively hunting ground for ocean predators.

The deep waters and rocky seabed make this region of the canyon ideal habitat for krill, squid, and fish, the foods their prey like to eat.

Knowing that these tasty lower organisms will bring out the sea lions, seals and other marine mammals of Monterey Bay, this group of orcas appears to have learned how to eat and find their food.

Researchers documented what happens when orcas band together to hunt a gray whale calf.
After the orcas separated the calf from its mother, an adult male rammed his head into her to stun her.

There are three main types of killer whales: transient, resident and deep-sea.

Residents tend to live in one place and hunt in groups for small to medium-sized fish, such as salmon, that do not defend themselves. Their larger family groups allow them to better locate their food and nutrition sources.

Marines tend to live in large groups nine miles or more from land and hunt sharks.

Transients live in smaller groups and hunt primarily mammals, making each excursion a potential fight to the death.

After stunning the gray whale calf, the orcas submerged the calf and drowned it by restraining it with their own bodies.
After killing the calf, the orcas fed on the calf’s lower jaw and tongue, its intestines visible above the water and its tail visible below the water surface at the bottom of the photo.
Researchers looked at how mammal-hunting killer whales (killer whales) in Monterey Bay, California, spent their time through 270 hours of behavioral observations. The findings provide insights into predator-prey interactions in this underwater canyon and deep-sea environment.

Actually, their name is inaccurate, because they tend to stay in the same areas near the coast as the residents. But decades ago scientists thought they were nomads and the name has stuck.

These groups of transients are the ones scientists observed in the latest study, carefully cataloging every sighting of them in Monterey Bay, mapping their locations and noting exactly what they were doing.

Most of their time (51 percent) was spent searching for prey, dividing that time fairly evenly between the sea canyon and open water.

Ten percent of their time was spent chasing prey, 23 percent feeding, nine percent traveling, six percent socializing, and one percent resting.

This graph shows the average number of killer whales (black solid line) and gray whales (gray dotted line) in Monterey Bay waters each month. Orca numbers increased from March to June, when gray whales migrated through Monterey Bay. In the spring, gray whales migrate from the tropics with their calves on their way back from their tropical birthing grounds to their Arctic feeding grounds.
Cookie-cutter marks on an orca indicate that it spends a lot of time in the open ocean, where the cookie-cutter shark lives.

The group of whales covered in the current study were transients and, although they hunted some in open water, they were mostly seen in and around the bay.

But recently a fourth group of killer whales has also been identified: the oceanic ones.

A previously unstudied group of 49 orcas has been hunting up to 190 miles off the coasts of California and Oregon, hunting prey as large as sperm whales, according to one study. study published last week.

Scientists might say that these whales spend much of their time in the open ocean because they have bite marks from cookie-cutter sharks, which only live there.

More than a decade ago, people had seen these distinctive wounds on orcas that live in the southern and western reaches of the Pacific, near New Zealand and Antarctica.

This deceased gray whale calf was found on the beach in 2011. The day before, scientists had seen a group of orcas attacking it in Monterey Bay. A and C show the animal’s missing jaw, and B shows the parallel cuts made by the orca’s teeth.
The “transient” orcas actually tended to hunt in the same area over the years, especially preferring the waters of the Monterey Canyon, an underwater canyon system that is ideal habitat for animals eaten by orca prey. .

But seeing them in orcas living near North America was something new.

Each of these groups of whales live extremely different lives and scientists have observed that they do not even speak the same language.

However, over time, changes in the environment are changing their habits.

Resident killer whale populations in many areas are collapsing as salmon runs become fewer and fewer.

In some cases, transients are arriving to replace them, thriving on seals and other creatures that live off the squid and smaller fish that can hold out where salmon cannot.

Over time, we will see how transient killer whales also adapt to a changing world.

He study was published today in the journal PLOS One.

Leave a comment