About 6,000 years ago, St. Paul Island, a tiny spot of land in the middle of the Bering Sea, must have been a strange place. Hundreds of miles away from the mainland, it was uninhabited except for a few species of small mammals, like arctic foxes, and one big one: woolly mammoths.
This population of woolly mammoths, one of the world’s last, had been comfortably living there for a few thousand years — they had no predators (humans didn’t arrive until the 18th century), a good amount of fresh water and plenty of food. But environmental changes, strikingly similar to those in our time, caused the mammoth population on this island to die out.
At the time, a changing climate caused sea levels to rise, shrinking both the island’s size and the mammoth herd. A drier climate meant less rainfall and lower lake levels, and the lack of freshwater may have been a driver of the mammoth’s extinction, according to a new study published Monday inProceedings of the National Academy of Sciences. The authors argue that this extinction offers important lessons about freshwater availability and island populations in a changing climate.
The study, led by scientists from Pennsylvania State University along with scientists from elsewhere in the United States and Canada, analyzed a variety of indicators to show that these woolly mammoths became extinct about 5,600 years ago. According to Russell W. Graham, a professor of geosciences at Pennsylvania State and the study’s lead author, this may be the most precisely dated prehistoric extinction.