"What killed the great beasts of North America?" Topic

"Until about 11,000 years ago, mammoths, giant beavers, and other massive mammals roamed North America. Many researchers have blamed their demise on incoming Paleoindians, the first Americans, who allegedly hunted them to extinction. But a new study fingers climate and environmental changes instead. The findings could have implications for conservation strategies, including controversial proposals for "rewilding" lions and elephants into North America.

The idea that humans wiped out North America's giant mammals, or megafauna, is known as the "overkill hypothesis." First proposed by geoscientist Paul Martin more than 40 years ago, it was inspired in part by advances in radiocarbon dating, which seemed to indicate an overlap between the arrival of the first humans in North America and the demise of the great mammals. But over the years, a number of archaeologists have challenged the idea on several grounds. For example, some researchers have argued that out of 36 animals that went extinct, only two—the mammoth and the mastodon—show clear signs of having been hunted, such as cuts on their bones made by stone tools. Others have pointed to correlations between the timing of the extinctions and dramatic fluctuations in temperatures as the last ice age came to a halting close.

To get a higher resolution picture of what may have happened, archaeologists Matthew Boulanger and R. Lee Lyman of the University of Missouri, Columbia, decided to look at a region that had not been well studied in the past: the northeast of North America, including the states of New York, New Jersey, Pennsylvania, Massachusetts, Maine, and the Canadian province of Ontario. "This is a region that has been virtually absent from discussions" about megafaunal extinctions, Boulanger says, which have mostly focused on the Great Plains and the American Southwest. "Yet it is also a region with an incredibly rich record" of prehistoric animal remains. For example, the bones of at least 140 mastodons and 18 mammoths have been found in New York state alone…"

Full article here
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Amicalement
Armand

Interesting article, Tango! It always seemed like it would be more dangerous to hunt megafauna than, say, mule deer, so I assumed there must have been a compelling reason to go after the big guys. The possibility that humans didn't hunt them to death provides at least a partial answer to the question

Gelber

Glad you enjoyed the article my friend.

Amicalement
Armand

Given the number of skeletons pulled from the La Brea tar pits, I'd say "tar pits".

Seriously, it's crazy.

Reading this article (I'd read the contrary view in "Guns, Germs and Steel") inspired me to google "did humans cause the extinction of north american megafauna". I hadn't realized that this was all such a sensitive political issue.

Interesting article and theory, though, I'll take it with a grain of salt since the sampling was so small (82 samples): "57 megafauna dates from 47 different sites and 25 Paleoindian dates from 22 sites." And all of these sites were in the Northeast (thought the authors admit that the results only applied to the Northeast.)

I'm also not so sure I about the overkill theory. It just doesn't seem possible that a small human population could extinct that many fauna -- Of course this thought is based only on opinion and not any scientific investigation :)

It always seemed like it would be more dangerous to hunt megafauna than, say, mule deer, so I assumed there must have been a compelling reason to go after the big guys.

Paleo-Indians definitely hunted mammoths. The Burning Tree mammoth, for one example, was butchered into four 'meat packages', then cached in a pond. They got enough meat from that one kill to feed the band for a month, and they never even bothered to retrieve it. Paleo-Indians were very capable hunters.

I saw a recent BBC series on megafauna, hosted by the lovely Dr Alice Roberts:

She interviewed an American palaeontologist who said signs of hunting overwhelmingly appear on the bones of large male mammoths. It seems these were targeted by human hunters.

He then went on to say that many mature females seem to have multiple injuries caused, he supposed,by juvenile males who would, in the natural order of things, be kept in their place by the lead male (he cited African elephants for this behaviour). Females would die early/lose their calves from these violent attacks by their own kind.

This he saw as a tipping point: lowered numbers breeding, that when climate change is factored in lead to extinction.