Rare drone footage shows 30 orcas attacking a pair of much larger gray whales, and trying to eat them alive

• Drone footage shows around 30 orcas attacking two adult gray whales in Monterey Bay, California.
• It is rare for orcas to attack adult gray whales, which are much larger animals.

Drone footage captured an extremely rare instance of 30 orca whales attacking and trying to eat two adult gray whales off the coast of Monterey Bay, California.

Monterey Bay Whale Watch, a whale-watching tour company, shared the footage on Facebook over the weekend, noting that it is the first time in more than 30 years that an "attempted predation" by orcas on adult gray whales has been documented in the area.

The whale-watching company said that it's fairly common for orcas, also known as killer whales, to hunt vulnerable gray whale calves. But, in this instance, it was two adult gray whales being attacked.

Evan Brodsky, the company's cinematographer who captured the footage, told KSBW Action News that the pod of orcas was trying to eat the gray whales alive.

The attack lasted around six hours, he said, per the news outlet.

Marine biologists with the company observed the attack, and said they were able to gain further insight into the "unique hunting strategies of the pod," as well as the "rarely seen defensive strategies of the two grays."

One video shows the orcas surrounding the two larger whales, with pools of blood visible in the water.

Orcas are significantly smaller than gray whales. An average gray whale weighs up to 78,000 lbs and is about 48 feet long. Orcas are usually under half that size, and just a fraction of the weight — around 11,000 lbs.

While the attack lasted hours, the orcas were ultimately unsuccessful. They backed down once the grey whales made it to shallow water near the beach, the whale-watching company said.

It added that the gray whales were badly hurt during the attack.

In 2017, a pod of orcas killed four gray whales near Monterey Bay in just a week, including a calf and its mother. The Guardian reported at the time that the orcas worked like "a pack of wolves" to separate the mother from her calf.