for National Geographic News
Scorpions are known as desert-dwellers with a venomous sting, but non- desert species may outnumber their relatives, and few species are actually dangerous.
The real animals are far more complex than the caricature. These fascinating creatures are found from the deserts of the American Southwest to the trees of Brazilian forests, as well as in British Columbia, North Carolina, and even the Himalayasand they've been around for hundreds of millions of years.
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What makes them tick is an adaptable lifestyle, a hardy metabolism, and of course their venomwhich is more complex than might meet the eye.
Scorpion populations spread slowly, but they can start a colony from a single pregnant female. That ability has allowed them to relocate to some surprising places.
"We have species of scorpions, introduced by humans, living in strange environments," said Victor Fet, a professor of biological sciences at Marshall University. He has observed a southern European species (found naturally in Italy, Greece, and Turkey) that has colonized two desert oases in Yemen and Iraqapparently by tagging along with ancient travelers.
"It has nothing to do with the desert," said Fet, "it lives in these areas, which were perhaps oases on ancient caravan routes. They are a long way away [from their range], across desert that the scorpions could not cross on their own. They were definitely delivered there by humans, so this is a kind of extreme example that shows how they can survive."
It's far from the only example. In the border area of Uzbekistan and Afghanistan, Fet encountered what he believes could be the most ancient of surviving scorpion family lines. In the high, desert-like mountains of the region, the animals appear only briefly in the spring of each year when they cling to the wet mud of temporary waterways. The rest of the year they retreat to cracks in the rock for hibernation.
"I think this creature is a remnant of times before deserts," Fet said. "Perhaps it was caught in the uplifting mountains which were once on the shores of the ancient sea. I think of this unique creature trapped in time and space, which still survives on an ancient ability to live and reproduce in an extremely narrow habitat, literally narrow, in a mountain canyon. Between the dry walls, on the mud under your feet, this relic species is sitting there."
How do scorpions thrive in such diverse places? Adaptability is the key, and it starts with food. Their diet, consisting largely of insects, is so diverse that they are seldom at a loss for something to eat. Scorpions are quite amenable to living in human habitats, like homes, where insects are plentiful.
In the desert, they employ exquisitely sensitive detectors to pick up vibration waves in the sand. These clues determine the direction and distance of preyeven when it's below the surface
Scorpions will eat lots of things, but they really don't need to eat much of anything. Their amazing ability to slow their metabolism to a third of the rate of another typical arthropod, like an insect, means they can get by eating as little as one insect a year. That in turn means they can survive in some of nature's harshest environments.
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