Quirks and Quarks

Penguin-like Great Auk extinction has human signature all over it

The last Great Auk died in the mid-19th century, and new research shows they weren't in natural decline, so their extinction was entirely a result of human over-exploitation.

They once teemed in their millions in the North Atlantic, but humans wiped them out

Great auks, buy John James Audubon (Audubon, The Birds of America)

New work using ancient DNA to study museum specimens supports the conclusion that the exclusive responsibility for the extinction of the Great Auk belongs to human hunters.

Great Auks once thrived across the north Atlantic in the millions, breeding on islands from Iceland to North America. There were huge colonies on islands off eastern Canada, like Funk Island off Newfoundland. 

The birds were large, flightless, and aquatic, with a strong resemblance to the penguins of the southern hemisphere, though they weren't part of the penguin family.

The last two known birds were killed by fishermen on Eldey Island, off Iceland in 1844.

University of Swansea biologist Jessica Thomas, who did her research at Bangor University in Wales, wanted to understand if human hunting merely contributed to the demise of the auk, or if the species might have been experiencing a natural decline before humans tipped it over the edge.

Great auks were found throughout the North Atlantic (BirdLife International, 2016)

A flightless bird is easy picking

Auks were common museum specimens, so Thomas had little difficulty finding bone and tissue samples from 41 specimens in museums across Europe, the UK and the US. The specimens cover the period from about 15,000 years ago, up to the extinction date.

DNA analysis of these specimens show no signs that the Great Auk was suffering any kind of natural decline due to climate change or other environmental challenges. They did not suffer from a lack of genetic diversity as had previously been speculated as a possible risk factor in their decline.

This leaves human over-harvesting as the only logical culprit in their disappearance.

The hearts from the last two great auks known. They were killed in 1844 for the purpose of study and collection (Natural History Museum of Denmark)

In the late 1400's, European fishing fleets discovered the rich fishing grounds off Newfoundland. where there were several important breeding islands. Auks were harvested for meat, for use as bait for fishing, and for their feathers. The harvesting was easy as the birds had no natural fear of humans, and no practical way to escape.

Thomas came across one account that described two fishing vessels catching 1000 auks in about half an hour. 

The Great Auk population went from an estimate of as many as 6 million birds to extinction in 350 years.

Great auk humeri collected from Funk Island used for DNA analysis (American Museum of Natural History/J. Thomas)

Great auk, great lesson

Thomas says the Great Auk provides a lesson about the vulnerability of a species even if it is abundant, which adds extra caution in the modern era when seabird populations are also challenged by habitat loss, climate change or even by-catch from fishing.

She points to the puffin as a species we should be cautious about, particular as recently it's become more popular as a 'trophy' hunted species.