Tuesday, 6 July 2010

Nut? What Nut? The Squirrel Outwits to Survive...

Who'd have thought that squirrels are such clever guys?!?! :)

I have to admit, I love the gray squirrel which I had first seen during my first trip to visit my Aunt in New Jersey, years and years ago. They are fatter and less shy than the red squirrels that live here in our country.

Actually, they are both dead cute and I found this very interesting article in the New York Times about squirrels and how they have managed to adapt so successfully and to survive as a species for million of years...

Nut? What Nut? The Squirrel Outwits to Survive

(by Natalie Angier)

I was walking through the neighborhood one afternoon when, on turning a corner, I nearly tripped over a gray squirrel that was sitting in the middle of the sidewalk, eating a nut. Startled by my sudden appearance, the squirrel dashed out to the road — right in front of an oncoming car.

Before I had time to scream, the squirrel had gotten caught in the car’s front hubcap, had spun around once like a cartoon character in a clothes dryer, and was spat back off. When the car drove away, the squirrel picked itself up, wobbled for a moment or two, and then resolutely hopped across the street.

You don’t get to be one of the most widely disseminated mammals in the world — equally at home in the woods, a suburban backyard or any city “green space” bigger than a mousepad — if you’re crushed by every Acme anvil that happens to drop your way.

The Eastern gray tree squirrel, or Sciurus carolinensis, has been so spectacularly successful that it is often considered a pest. The International Union for Conservation of Nature includes the squirrel on its list of the top 100 invasive species. The British and Italians hate gray squirrels for outcompeting their beloved native red squirrels. Manhattanites hate gray squirrels for reminding them of pigeons, and that goes for the black, brown and latte squirrel morphs, too.

Yet researchers who study gray squirrels argue that their subject is far more compelling than most people realize, and that behind the squirrel’s success lies a phenomenal elasticity of body, brain and behavior. Squirrels can leap a span 10 times the length of their body, roughly double what the best human long jumper can manage. They can rotate their ankles 180 degrees, and so keep a grip while climbing no matter which way they’re facing. Squirrels can learn by watching others — cross-phyletically, if need be. In their book “Squirrels: The Animal Answer Guide,” Richard W. Thorington Jr. and Katie Ferrell of the Smithsonian Institution described the safe-pedestrian approach of a gray squirrel eager to traverse a busy avenue near the White House. The squirrel waited on the grass near a crosswalk until people began to cross the street, said the authors, “and then it crossed the street behind them.”

The Eastern gray is one of about 278 squirrelly species alive today, a lineage that split off from other rodents about 40 million years ago and that includes chipmunks, marmots, woodchucks —  a k a groundhogs — and prairie dogs. Squirrels are found on all continents save Antarctica and Australia, and in some of the harshest settings: the Himalayan marmot, found at up to 18,000 feet above sea level, is among the highest-living mammals of the world.

Gray squirrels use their sharp, shaded vision to keep an eye on each other. Michael A. Steele of Wilkes University in Pennsylvania and his colleagues have studied the squirrels’ hoarding behavior, which turns out to be remarkably calculated and rococo. Squirrels may be opportunistic feeders, able to make a meal of a discarded cheeseburger, crickets or a baby sparrow if need be, but in the main they are granivores and seed hoarders.

But the squirrels don’t just bury an acorn and come back in winter. They bury the seed, dig it up shortly afterward, rebury it elsewhere, dig it up again. “We’ve seen seeds that were recached as many as five times,” said Dr. Steele. The squirrels recache to deter theft, lest another squirrel spied the burial the first X times. Reporting in the journal Animal Behaviour, the Steele team showed that when squirrels are certain that they are being watched, they will actively seek to deceive the would-be thieves. They’ll dig a hole, pretend to push an acorn in, and then cover it over, all the while keeping the prized seed hidden in their mouth. “

For the complete article go here.

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