Thirsty, Lonely Woolly: Earth's Last Mammoth Went Extinct Due to Water Scarcity

An international team of scientists has revealed that 5,600 years ago, the world's last woolly mammoths on St. Paul Island, Alaska, were literally dying for a drink.

According to a study published in the journal Proceedings of the National Academy of Sciences, the scientists tried to determine the exact date of the woolly mammoths' extinction on the island.

They did this by analyzing three different spores from fungi present in large animal dung. The spores were found in a lake core near a cave where the woolly mammoths previously thrived.

Professor Russel Graham from Pennsylvania University explained that the three spores, which were from large animals such as mammoths, served as markers to determine the time that the animals were alive.

"We see a reduction in the three species of fungus, all of which are associated with the dung of large animals," Graham revealed via EurekAlert.

The study also showed that mammoth DNA was present in the lake cores of the island until 5,650 years -- give or take 100 years -- but suddenly disappeared after that period.

Apart from pinpointing the woolly mammoth's time of extinction, the team also unlocked the reason behind it by studying 14 remains of the said species recovered from the island and investigated the environmental changes during that period.

The results showed that St. Paul Island, which was formerly a part of the Bering Land Bridge, experienced drastic shrinkage in land area due to climate change. Decrease in land size meant that there would be smaller resources such as fresh water and vegetation available for the mammoths.

The findings revealed that not only did the amount of freshwater decrease, there was also a possibility of contamination. As sea levels rose, sea water slowly entered the lake systems, making the island's water sources not fit for consumption, the New York Times reported.

The study sheds light to the future of small, low-lying islands and the species living in it, showing their vulnerability to natural changes in the environment.