Orcas are highly social, complex animals. They take care of each other’s young and live with their mothers for their entire lives. The females go through menopause, and live for decades after. Different pods use distinct dialects in their calls. All of this makes them one of the animal world's most exceptional species, and one that has long fascinated humankind. 

In some cases, people have taken advantage of orcas’ unique intelligence to form cooperative working arrangements—to the detriment of other whale species. 

In New South Wales, Australia, the port town of Eden was once the epicenter of the country’s whaling industry. For almost a century, killer whales worked with human whalers to take down humpbacks in a mutually beneficial hunting arrangement. 

Starting in the 1840s and continuing until the 1930s, pods of orcas in the area were known to assist hunters by herding other whales, leading the whalers to humpbacks and allowing whalers to harpoon them. In exchange, the hunters would allow the orcas the first shot at the body. 

In reviewing a new book about sperm whales and orcas, The Cultural Lives of Whales and Dolphins, New York Review of Books writer Tim Flannery describes the practice:  

After a humpback was lanced and killed by the men, they observed the ‘law of the tongue.’ The whalers would leave the humpback body for twenty-four hours so that the killers could feast on the lips and tongue.

A 2004 documentary from the Australian Broadcasting Corporation tells their story through eye-witness accounts:

The working relationship between the whalers and orcas was so fine-tuned, the whales would swim right up to the shore, alerting the whalers to their presence in the bay. The whalers would sometimes go out hunting at night, following the orcas to their prey in the darkness. If the people lost track of their orca guides, they would slap the surface of the water with their oars, and the orcas would double back. One eyewitness to the hunts, in his 80s when he was interviewed by the documentarians, compares the orcas' herding skills to "a cattledog [working] the sheep."

There were as many as 36 whales in the pod of hunting assistants; 21 of them had names and were well-known to the townspeople of Eden. The skeleton of the most famous hunting orca, Old Tom, is now housed in the Eden Killer Whale Museum. His teeth show a distinctive groove from one of his favorite antics, clinging to the rope attached to a harpooned whale so that the boat would tow him around. Tom's death signaled the end of the whaling industry in Eden.