Saturday, December 26, 2015

Xenophobic Orcas

I was reading this, and was blown away:
An equally odd aspect of killer whale culture concerns food taboos and ways that whales observe them. In this they offer an extraordinary parallel with some human cultures. One clan of killer whales eats only a single species of salmon. Another kills only one species of seal. When members of a mammal-eating clan were captured for the aquarium trade in the 1970s, they starved themselves for seventy-eight days before eating the salmon being proffered, and then they ate the fish only after they had performed a strange ceremony. The two whales held gently onto either end of a dead salmon, and swam a single lap around their pool with it in their mouths, before dividing the fish between themselves and consuming it.

Killer whales are strongly xenophobic. Clans of salmon eaters never mix with mammal eaters, for example. Genetic studies show that clans with different food taboos don’t interbreed, leading to slightly different appearances and genetic makeup. Each clan has a distinctive dialect of vocalizations (perhaps we should call them languages), which facilitates coordination of their work, division of their labor, and care of one another.

At times, killer whales have developed special relationships with people. During the nineteenth and early twentieth centuries, at Twofold Bay south of Sydney, Australia, killer whales and humans set up a mutually profitable whaling enterprise. The killer whales would notify the whalers of the presence of humpback whales by performing a ritual in the waters of the bay fronting the whaler’s cottagers. The men would harpoon the humpbacks, and the killer whales would hold on to the harpoon ropes to tire the prey.

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. Remarkable proof of this partnership persists, in the form of the skeleton of “Old Tom”—a killer whale whose teeth were worn flat on one side while holding onto harpoon ropes—which can be seen in the killer whale museum in the town of Eden, Australia.

With the exception of our species, killer whales are earth’s most capable predators. When they evolved ten million years ago, half of earth’s whales, seals, and dugong species became extinct. Because they specialize in a particular food type and are so intelligent, killer whales continue to have a huge impact on their prey. As a result of global warming, killer whales have appeared in Arctic waters. Horrified Inuit describe them as voracious and wasteful killers that have reduced populations of some Arctic mammals by a third.

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