Arctic fox likely evolved
from a Himalayan
ancestor, study says
yereth@alaskadispatch.comJune 17, 2014
The cold Himalayan region is sometimes referred to as Earth's "third pole," and the study title -- "From 'third pole' to north pole" -- invokes that reference.
The newly-discovered fox species has been named
Today's Arctic foxes are likely descendants of foxes that acclimated to cold and extreme conditions millions of years ago in the Himalayas, claims a new study that examined fossilized remains found in Tibet.
The study, published in the academic journal Proceedings of the Royal Society B: Biological Sciences, challenges the theory that the Arctic fox evolved in Europe, and spread its range as the last series of Ice Age cycles hit about 2.6 million years ago.
The study is based on the remains of a newly-discovered species of fox, between 3 million and 5 million years old, that researchers say appears to be the first evolutionary link to modern Arctic foxes. The fossilized fox has dental features that are "highly hypercarnivorous," suitable for the mostly meat diet that is common for Arctic predators, including Arctic foxes, said the study, led by Xiaoming Wang of the Natural History Museum of Los Angeles County.
The fossilized fox remains were found in the Zanda Basin in southern Tibet during a 2010 expedition led by Wang, the museum said.
Also found during the expedition were remains of other extinct species, including woolly rhinos and types of horses, snow leopards and other cold-weather mammals.
The discoveries support the theory that several modern Arctic animals are descendants of animals from ancient Tibet that were already adapted to cold and extreme conditions before the Ice Age. The discovery site is at an elevation higher than 14,000 feet, and the ancient animals' remains have been found at lake margins. It is a difficult working environment, said Wang.
"There are a lot of challenges," Wang said in a statement issued by the museum, "but in paleontological terms, it is a relatively unexplored environment. Our efforts are rewriting a significant chapter of our planet's recent geological history." Vulpes qiuzhudgingi, in honor of Qiu Zhuding, a paleontologist at the Chinese Academy of Sciences in Beijing
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Basic Facts About Arctic Foxes
To live in such cold places, have several adaptations that allow them to survive. Their round, compact bodies minimize surface area that is exposed to the cold air. Their muzzle, ears, and legs are short, which also conserves heat.
Of course, the defining feature of fox is their deep, thick fur which allows them to maintain a consistent body temperature. Arctic foxes also have thick fur on their paws, which allows them to walk on both snow and ice.
© Jeffrey Kerby
Diet
Lemmings are the staple food for Arctic foxes. However, they are quite opportunistic, and will eat whatever is available out on the frozen tundra, even if it means scavenging leftovers from other predators, such as polar bears!Population
Arctic fox populations range in the hundred thousands, but fluctuate with the available lemming population.Range
Did You Know?
Arctic foxes change the color of their fur with the seasons. In winter they are white to blend in with the snow, while in the summer they change to brown!
The Arctic fox is found throughout the entire Arctic tundra, through , Canada, , Russia, , , and even , where it is the only native land mammal.Arctic foxes change the color of their fur with the seasons. In winter they are white to blend in with the snow, while in the summer they change to brown!
Behavior
The tundra is not an easy place to live. It is barren, rocky, and without much vegetation. Arctic foxes are extremely well adapted to their frigid homes, and have secured a niche where they make the best out of almost any situation.One of the most unique and interesting behaviors of Arctic foxes is how they hunt. They have incredible hearing, aided by their wide, front-facing ears, which allow them to locate the precise position of their prey beneath the snow.
When fox hears its next meal under the snow-pack, it leaps into the air and pounces, breaking through the layer of snow right onto the prey beneath.
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