Dying for a drink: Thirst killed last of the mammoths, study finds

Humans are believed to have hunted most of the mammoths to extinction. © Pichi Chuang
While humans hunted the woolly mammoth to extinction, an isolated island off Alaska housed a population that outlived their mainland family by 5,000 years. Thirst likely led to the eventual extinction of the St. Paul Island mammoths, however.

Baffled by what killed off the species on the island after such an extended period, a new study from the University of Alaska Fairbanks has pinned their decline 5,600 years ago to a lack of freshwater resources.

The island, situated between Russia and the US and without rivers or springs, experienced dry conditions and rising sea levels leading to the depletion of freshwater sources and salt water seeping into the little supply left, according to the study.

Scientists have been without an answer for the mammoths’ decline for years as humans did not arrive on St. Paul Island until 1787, long after they were gone. Food sources are also believed to have been plentiful with no evidence of any volcanic activity.

By examining the microbes and isotopes in sediment cores found near freshwater sources at the time, the study believes that water supplies were getting shallower and saltier as sea levels rose. St. Paul Island was part of a land bridge connecting Russia and the US until rising sea levels cut if off from land.

As the mammoths battled rising temperatures and reduced landmass, the study states that “degradation of water quality by intensified mammoth activity around the lake likely exacerbated the situation.”

The aptly-named Dr. Matthew Wooller, who was involved in the study, told the Telegraph that “it paints a dire picture of the situation for these mammoths.”

“Freshwater resources look like the smoking gun for what pushed them into this untenable situation," Wooller said.

The University of Maine’s Jacquelyn Gill worryingly warned the Atlantic that rising sea levels and reduction in space is also a “likely model for extinction in the near future.”

READ MORE: Mammoth hunt shows humans active in Arctic 45,000yrs ago – Russian scientists