Woolly mammoths were once a common sight across the frozen landscapes of the Ice Age. Were they able to swim?
While there is no evidence of the woolly mammoth swimming, it is safe to assume that it was capable. Columbian mammoths swam several miles to reach the Channel Islands off the coast of California. Asian elephants, the closest living relatives of mammoths, are very strong swimmers.
For more on why woolly mammoths could probably swim, read on.
Regarding mammoths, the compelling question is not whether they could swim; they certainly had the physical capacity to be strong swimmers. The question is whether or not they did swim, and why they might have decided to do so.
Remains of Columbian mammoths, a close relative to the woolly mammoth but probably less hairy, were discovered on California’s Channel Islands. Scientists believe that the species could only have made its way to the islands by swimming from the North American mainland.
If true, this means that mammoths were not only swimmers but strong swimmers, given that the islands lie 12 miles from the Californian coast. Once these mammoths reached the Channel Islands, they remained there.
Across many generations, the Columbian mammoths on the islands underwent a process known as “insular dwarfism”. This occurs when a species lives in a relatively restrictive space for an extended period and adapts by evolving to become smaller.
In this example, these Columbian mammoths evolved into the “pygmy mammoth”. At just five and a half feet tall, the pygmy mammoth was less than half the height of the Columbian mammoth.
Swimming is the only explanation for the mammoths reaching the Channel Islands. There are no traces of other Ice Age animals such as sabercats or sloths on the islands.
While the Columbian mammoth would have needed to swim to reach its destination, it might not have been as long a journey as it would be today. As huge glaciers formed during the Ice Age, the sea level would have lowered and reduced the amount of water between the Californian coast and the Channel Islands.
The fact that mammoths have been discovered on islands such as those off the coast of California make their sudden decline and extinction even more puzzling.
Climate change has often been cited as the reason for mammoths dying out, but the mammoth population off the coast of California would have experienced numerous changes in climate.
It is possible that these island mammoths eventually fell victim to a lack of genetic diversity. Human hunters might not have affected mammoths in remote locations directly, but if they prevented more mammoths from making the journey to the islands, it would have been very detrimental.
Woolly mammoth remains have been found on a number of islands in the Arctic Circle, most notably off the northern coasts of Russia and Alaska. Wrangel Island, off the Russian coast, is believed to have been the last refuge of the woolly mammoth before it became extinct.
Without an influx of fresh DNA, the mammoths would have eventually suffered from the effects of inbreeding. These effects have been studied in the woolly mammoths found on Wrangel Island, which showed signs that the mammoth was in a state of “genetic meltdown” before its extinction at the hands of hunters.
It is unclear how often woolly mammoths used their ability to swim, or whether or not they would have needed to. Living in the freezing climate of Ice Age Europe, Asia, and North America meant they would have had little reason to swim except on rare occasions.
The woolly mammoth’s closest living relative, the Asian elephant, is known to be a strong swimmer. In fact, elephants are considered among the strongest swimmers of all land mammals.
Elephants can swim great distances, with documented instances of them swimming as far as 23 miles to islands that are not even visible to them. They usually follow their sense of smell in these cases, sensing fruit and other vegetation in the distance.
Elephants use their trunks to breathe while their mouths are underwater, similarly to how humans use a snorkel. There is no reason to believe that mammoths didn’t employ a similar method while crossing bodies of water.
Unfortunately, the mammoth’s ability to swim to remote islands ultimately did not save it. The last woolly mammoths died approximately 4,000 years ago and the species was rendered extinct.