Orcas have been known to pick fights with everything from sharks to yachts, but a pod in Western Australia recently learned the hard way that they should really leave sperm whales alone. Off the state's southern coast, viewers on a whale-watching tour following the orcas realized the creatures were pursuing something underwater. Marine biologist Jennah Tucker, who works for the tour company, told the Australian Broadcasting Corporation that it was a pod of sperm whales that fended off the attack by forming into a "rosette" circle. According to ScienceAlert, this is a defensive move where the whales huddle together "with their tails pointed outwards and the youngest and most vulnerable member tucked in the middle."
What came next was unexpected. As an orca dubbed Wonks dove toward the circle, one of the sperm whales released an enormous cloud of poop. Wonks "peeled away quickly," the tour company recounted on its website, and when another orca named Shredder went in, more whale poop was hurled, sending Shredder fleeing. "It's called defensive defecation," Tucker told ABC of the rarely witnessed (and quite stinky) phenomenon. And in this case, it worked out for the sperm whales, who were able to fend off the hourlong attack. "It was like the orcas said, no, not worth our time. Everyone move out," Tucker said.
Sperm whale poop is reddish due to their squid-based diets, so observers initially worried the red cloud that appeared in the water was blood from one of the smaller sperm whales they believed was a calf. It was only when they watched video footage later that they realized the cloud was definitely not blood. Tucker noted that sperm whales are an apex predator, so orca attacks against them aren't all that common. "It's actually pretty adventurous for orcas to try to take on sperm whales," she said. "They're punching above their weight." (More stories about sperm whales.)