A Cunning Australian Orca

One of the highlights of my recent summer holiday was the Eden Killer Whale Museum. Eden is located on Twofold Bay, the southeastern-most deepwater harbour on mainland Australia. Eden was the base for shore-based open-boat whaling from 1828-1928. This is the sort of whaling where, when a shore-based lookout spotted a whale, the whalers would row out in longboats, harpoon the whale, get towed around until the whale tired, and then finish it off. In the early 20th century, however, the Eden whaling operations became unique, in that humans were not the only ones hunting the whales.

My brother and I posing with the skeleton of a whale-hunting orca

The Eden whalers developed a whale-hunting relationship with a pod of killer whales, which allowed them to continue shore based whaling until the development of factory whaling in the mid-20's.

Alternatively, a pod of killer whales domesticated the Eden whalemen, in order to provide easy dinners.

According to the museum (which contains several grainy pre-war photos of orcas cruising alongside whale boats and rorqual carcasses), the killer whales would find a baleen whale, chase it into Twofold Bay, and then alert the whalers. These humans would then harpoon the whale, and the orcas would expedite the whale killing process by hanging onto the harpoon hawser to increase drag and rolling the harpooned whales to prevent them from sounding.

Once the whale was killed, the orcas would eat the tongue (Baleen whales have very large tongues), and leave the carcass for the whalers to extract blubber from.

While this story falls squarely into the “stranger than fiction” department, the cool thing for me was the paleontological evidence. Two years after the last whale was taken, the body of one of the whale-hunting orcas washed up in the bay. The remains were processed, and the skeleton is now on display in the museum, where my brother and I found it.

The coolest feature is hard to see in the photo above, but thankfully Tim Cole and Nick Hodge have a better image on Nick’s blog. As seen in some of these pictures, the first six teeth on the whale’s lower left jaw have been worn down to the gum line. The seventh tooth (and to a lesser extent, the eighth and ninth) has a clean, rounded notch, which is consistent with the expected wear from a harpoon hawser or other medium-weight rope. So the skeletal evidence actually supports the historical reports of orcas towing boats or joining in on a Nantucket sleigh ride.

If anyone else out there knows of cleverer symbiotic behavior between non-domestic species, I’d love to hear it.