A woolly mammoth that lived 14,000 years ago travelled more than 1,000km across North America, before encountering humans.
Analysis of the female mammoth’s tusk, which was found in Alaska, US, in 2009, has shown she ventured into areas where humans had recently established camps.
“She wandered around the densest region of archaeological sites in Alaska,” says lead author Audrey Rowe, a PhD student at the University of Alaska Fairbanks.
“It looks like these early people were establishing hunting camps in areas that were frequented by mammoths.”
The mammoth was named Élmayųujey’eh, or Elma, by the Healy Lake Village Council (the local tribe where the tusk was found).
Elma’s tusk was found with two juvenile mammoth tusks at a site that also had evidence of campfires, stone tools, and the remains of other game. This, say the researchers, adds further evidence to the theory that humans hunted mammoths.
The researchers examined the isotopes to learn where the mammoth had been and what she had eaten. Isotopes are atoms of the same element that vary slightly, giving researchers a chemical signature.
Different places around the globe, and different food sources, can have different isotopic signatures that end up in the bones of animals. Mammoth tusks are particularly good isotope records because they keep growing throughout the creature’s life.
In this case, the researchers found that Elma had moved from northwestern Canada, 1,000 km away, to the Alaskan site where she was found. She covered the distance in 3 years.
They also show she was about 20 years old.
“She was a young adult in the prime of life,” says senior author Matthew Wooller, director of the Alaska Stable Isotope Facility and a professor at the University of Alaska Fairbanks. “Her isotopes show she was not malnourished and that she died in the same season as the seasonal hunting camp at Swan Point where her tusk was found.”
The ancient DNA analysis shows that Elma was closely related to the two other tusks found at the site, and distantly related to mammoths found at a nearby site.
Elma’s travels mark a similar journey to one taken by a male woolly mammoth 3,000 years prior. But Elma lived in the roughly 1,000-year period of overlap between woolly mammoths and humans in North America.
By 13,000 years ago, the population of woolly mammoths was declining rapidly. Human hunting is a cause of this, but the researchers also point out that the receding ice age would have compounded the problem.
“Climate change at the end of the ice age fragmented mammoths’ preferred open habitat, potentially decreasing movement and making them more vulnerable to human predation,” says co-author Ben Potter, an archaeologist and professor of anthropology at University of Alaska Fairbanks.
“This is a fascinating story that shows the complexity of life and behaviour of mammoths, for which we have very little insight,” says co-author Hendrik Poinar, evolutionary geneticist and director of the McMaster Ancient DNA Centre, Canada.