Today in the Sixth Extinction

Just in case you were wondering how much the extinctions of the past few hundred years are caused by humans, the answer is nearly all of them.

Not so long ago, the northern seas were full of great auks. Every summer, millions of the two-toned, goose-sized birds would gather at different breeding grounds across the North Atlantic. The flightless birds were easy to capture, and passing sailors loved how they tasted.

“In less than half an hour we filled two boats full of them,” the French explorer Jacques Cartier wrote after encountering a throng near Newfoundland in 1534. Collecting them was as easy “as if they had been stones.”

Just three centuries later, though, the species had become famous for its scarcity instead. Museums and merchants started paying top dollar for great auk eggs and skins. In 1844, members of a small expedition found two of the birds on an Icelandic island, strangled them and crushed their only egg. That was the last confirmed sighting. In this way, the great auk went extinct.

What caused such a precipitous decline? In the past, researchers have speculated that environmental change topped off by human greed took down the great auk. After all, that’s what people think happened to woolly mammoths.

But new research points the finger more squarely at us. A paper published last month in eLife which uses genetic analysis from museum specimens to reconstruct great auk population trends, suggests “there was no reason for them to go extinct if they hadn’t been hunted,” said Jessica Thomas, a scientific officer at Swansea University in Wales and the lead author of the study. This puts great auks in the same doomed-by-humans category as the passenger pigeon and the moa.

While there are limits to how much you can learn about historic population changes from genetic data, the paper shows “how this type of reconstruction might be applied to better understand other species conservation problems,” said Tim Wootton, an ecology and evolution professorat the University of Chicago who was not involved in the research.

Humans have been hunting great auks for millenniums. But starting around the 15th century, they became a staple for sailors traveling near the American and European coasts. Crews ate their eggs, brought them onboard as mobile food sources and plucked out their feathers to sell to pillow-makers. They even burned their oil-rich bodies for fuel.

This is of course the future for the majority of species on the planet, whether by intention or through indifference, mostly in the next century.