Previous research had blamed their demise on tribal hunting. But new findings “pretty much dispel the idea of any one factor, any one event, as dooming the mammoths,” said Glen MacDonald, a researcher and geographer at the University of California in Los Angeles, to LiveScience.com.
In other words, hunting didn’t help, but it was not instrumental. The ancestors didn’t do it.
So what did? After thriving for 250,000 years, the huge mammals lingered on in dwarf form in the Arctic Ocean’s Wrangel Island until 3,700 years ago. Between 20,000 and 25,000 years ago, LiveScience said, the animals declined during the worst of the last major ice age, though they started to multiply in warmer interior Siberia.
Analyzing samples from more than 1,300 woolly mammoths as well as 450 pieces of wood, 600 archeological sites and upwards of 650 bog lands in Beringia—the former land bridge under the Bering Strait, thought to be the giant mammoths’ last habitat—a team led by MacDonald discovered a host of things working against them.
The beasts were felled by a combination of declining food supply and terrain that deteriorated into peatlands, all brought on by warming climate, said the study as quoted in USA Today. Grasses and willow, mammoths’ normal food, was replaced by poisonous birch to eat, and solid ground gave way to wetlands more difficult to tread upon, USA Today said.
“Pressure from hunting was also present, as contemporary Paleolithic sites are numerous in both Siberia and now in northwestern North America,” the study said. “Modeling studies show that given the environmental stresses at the time, even limited hunting by humans could have significantly contributed to woolly mammoth extinction.”
Together these factors conspired to push the mammoth population down further, MacDonald said.
“Mammoths faced profound climate change and very profound changes in their habitat and landscape, and also faced pressure from humans,” MacDonald told LiveScience, adding that such changes have implications for current climate issues.
“Now think about the twenty-first century, where we’re seeing rapid climate change, massive changes in the landscape and certainly pressure from humans on the environment,” he said. “Species today are facing the same sorts of challenges the mammoths did, but the rate of those changes today are much greater than what mammoths faced.”