Wooly mammoths, the prehistoric pachyderms renowned for their popularity in Ice Age-genre movies and their ability to scatter tribes of primitive man with little more than a bellowing roar – at least according to Ice Age-genre movies – died out because of lack of potable water, according to a new study.
The last group of wooly mammoths, living on St. Paul Island in the Bering Strait, fell victim to fresh water being contaminated by nearby ocean water, according to research led by Penn State University professor Dr. Russell Graham and published in this week’s edition of the journal Proceedings of the National Academy of Sciences.
According to BBC News and the Daily Mail, post-Ice Age warming of the planet caused the sea levels to rise and the mammoths’ island habitat to shrink in size.
“Furthermore, some of the freshwater lakes that they used to keep hydrated were flooded by saltwater from the ocean, leading to increased competition for the few remaining watering holes. The increasing number of mammoths using these lakes ultimately made them unusable as well, Dr. Graham said.
“As the other lakes dried up, the animals congregated around the water holes. They were milling around, which would destroy the vegetation – we see this with modern elephants,” he told BBC News. “And this allows for the erosion of sediments to go into the lake, which is creating less and less fresh water. The mammoths were contributing to their own demise.”
While most of the world’s wooly mammoth population died out by approximately 10,500 years ago, the group on St. Paul Island managed to survive for another 5,000 years before lack of fresh water brought about their extinction.
“Graham and his colleagues reached this conclusion after analyzing the remains of 14 wooly mammoths using radiocarbon dating, and collecting sediments from underneath the lake floor in order to study their contents in order to determine what the lake environment was like at various points throughout history,” according to the online science website Red Orbit.
Researchers believe the mammoths on St. Paul Island survived 5,000 years longer than other mammoths when they became trapped on the island after a land bridge was submerged by rising sea levels.
They survived until conditions worsened, and the influx of saltwater combined with the lack of freshwater from melting snow or rain caused their sources of drinking water to become increasingly limited, according to Red Orbit.
“We do know modern elephants require between 70 and 200 liters of water daily,” Dr. Graham told BBC News. “We assume mammoths did the same thing. It wouldn’t have taken long if the water hole had dried up. If it had only dried up for a month, it could have been fatal.”