UNDER ATTACK BY ORCAS, SPERM WHALE EMPLOYS ‘DEFENSIVE DEFECATION’

A sperm whale has been observed employing a unique defence mechanism during an attack by orcas off the coast of Australia. The whale released its bowels during the attack, which caused the orcas to put some distance between them and their prey.

The tactic actually has a scientific name. “It’s called defensive defecation,” marine biologist Jennah Tucker told ABC News in Australia. “And it seems like it actually did work in this case.”

The journalist interviewing her seemed to be having more fun naming the strategy, referring to it as a “poo-nami” and declaring it “stinky but brutally effective.”

Tucker witnessed the attack, in which a pod of orcas, one of Earth’s more fearsome apex predators, went up against a group of young sperm whales, one of the largest creatures ever to have lived, and an apex predator in its own right. It’s a rare matchup.

“It’s actually pretty adventurous for orcas to try to take on sperm whales,” Tucker said. “They’re punching above their weight.”

The attack happened at Bremer Canyon, a marine hot spot off Western Australia’s southern coast. Tucker was aboard a tour boat and saw the dirty deed, in which the whale defecated and then swished its tail through the resulting mess to fend off, confuse, or perhaps just gross out the predators.

A blog post from Whale Watch noted that on two occasions the largest sperm whale deliberately defecated on the orcas as they approached, “which worked ... to disorientate and create a rather unpleasant experience for the orca. (One) got covered and was not very pleased as he peeled away quickly.”

Tucker said the whales were initially huddled together in a circle, with their heads together and their tails fanned out, a defensive posture known as a rosette. She said they looked exhausted from the chase. “They were sort of poking their heads out of the water and letting out these huge heaving breaths.”

Then a dark red bubble rose to the surface. Tucker said the human observers went quiet because they thought it was blood. “But then the killer whales all just moved off really suddenly.”

Only later after observing the video they took did scientists realize what they had witnessed. “Because sperm whales’ diet consists mostly of squid, they actually have this really reddish coloured poo,” she noted.

The attack, which had lasted for more than an hour, petered out as the orcas began to lose interest and withdraw from the still unharmed sperm whales. “It was like the orcas said: ‘No, not worth our time, everyone move out,’ ” said Tucker.