Wooly mammoth died off due to depletion of drinking water

woolymammoth

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.”

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World’s only wild horse appears to be on the rebound

przewalski-horses-on-a

Seventy years ago the world’s only wild horse, called the Przewalski’s horse, was extinct in the wild and down to fewer than three dozen animals in captivity.

Today, that number has not only swollen to some 2,000, but hundreds have been reintroduced into the wild, including six Przewalski’s horses that were recently released into a vast, 40,000-plus-acre unbroken plot of virgin steppe in Russia, near the border with Kazakhstan.

Native to China, the stocky, tan-colored horse once inhabited the Eurasian steppe, including Mongolia, Kazakhstan, Russia and Ukraine, according to the International Union for Conservation of Nature.

These hardy creatures enjoy rolling around in the snow, scratching their backs on the crusty surface, according to Przewalski’s horse expert Tatjana Zharkikh, who heads the Russian reintroduction project.

“They are not afraid of wind, snow, cold … If the Przewalski’s horse has enough food, it is practically invincible,” she said.

The Przewalski’s horse is considered the world’s only wild horse because it has never been domesticated, unlike some equines found in the western US that, while untamed, are descendants of domesticated animals.

This winter marks the first in the wild for the half dozen Przewalski’s horses introduced into the Orenburg Reserves, a cluster of six strictly protected nature areas, according to Agence France-Presse.

Przewalskis horse.

Przewalski’s horse.

The animals were born at a reserve in the south of France.

Other horses have been released into the wild at locations in Mongolia.

The species was discovered by Russian explorer Nikolai Przhevalsky, who described it in the 19th century. After its discovery, there was a ruthless effort to capture the animals.

“Herds were chased down to exhaustion to capture the young foals,” Zharkikh told Agence France-Press, “but in the end the process secured enough animals to save the species after they had gone extinct in their natural habitat.”

The 2,000 animals alive today are descendants of just 12 wild-caught horses. Breeding a viable population from such a limited gene pool has not been without difficulties.

Also, unlike what happens when a horse and donkey reproduce, Przewalski’s horses can breed with domestic horses and produce fertile hybrids, which are a threat the species’ gene pool.

“Even a few hybrids can cancel out all conservation efforts,” Zharkikh said. “What is the point of protection if they are just cute shaggy-haired horses rather than a species?”

“Our goal is to form a reserve of genetically pure animals,” said Rafilya Bakirova, director of Orenburg Reserves, who would like to expand the project, including working with neighboring Kazakhstan.

A wild population would only work if the protected area is much larger, Zharkikh said, 250,000 acres or more.

(Top: Przewalski’s horses on a snow-covered field in the Orenburg Reserves. Photo credit: Agence France-Press via Tatjana Zharkikh.)