A Desert Scorpion

15 Mar 2019

This morning, after a night’s observing, I cooled down with a cup of tea and watched Scorpius scuttling up from the eastern horizon. The Kalahari abounds in scorpions; they are an element of the summer night landscape. But they hibernate during our freezing winter nights, so it is marvelous to have our celestial scorpion grace our winter skies.

Through what has been gleaned from the remnants of cuneiform tablets and artifacts found in the valley of the Euphrates River, Scorpius goes back as far as the Akkadian and Sumerian civilisations around 3,500 B.C. It’s fitting this magnificent constellation is so ancient as scorpions are believed to have evolved from amphibious ancestors 425 to 450 million years ago in the Silurian Period – long before the dinosaurs. Clearly they were an evolutionary success story – modern scorpions are virtually unchanged since then, earning scorpions the title of ‘living fossils’. 

Some of the world’s most venomous scorpions are found in the deserts of the Middle East – how propitious it must have seemed to those ancient peoples to have that giant, fierce, menacing constellation scuttling across the night sky, as its venomous terrestrial counterpart must have scuttled across their lives. One can only assume that among those ancient desert-dwellers the fear factor of the dread scorpion with its terrible sting, some lethal to humans,  was as tremendous as it is among these present-day Kalahari desert dwellers.

There is something about that combination of grasping pincers and curved sting that sparks terror in the human brain. Indeed, scorpions have inspired fear and loathing throughout the ages. 

“Scorpions are a horrible plague,” declared Pliny, the ancient Roman naturalist and historian, “poisonous like vipers except that they inflict even worse torture by killing their victims with lingering, painful death that lasts three days.”

“Everyone detests scorpions,” chimed in Aelian, another natural historian of ancient Rome. He went on to write, “There are so many scorpions on the second stage of the road from Susa to Media that three days before he travels along it, the King of Persia commands everyone to hunt for them, and he gives rewards to the person who catches the most.”

Today, as then, scorpions are among the world’s most misunderstood and feared creatures. Even among those who should know better, there is vast misinformation and ignorance about scorpions and their venom. Scorpions are not as dangerous as many people believe. South Africa has 160 identified species and only one has venom powerful enough to be lethal to humans, although deaths are very rare.

Once people look past their fears, they can start to see scorpions as the fascinating and beneficial creatures that they are. Scorpions are extremely valuable components to natural eco-systems, as they play complex roles of both prey and predator (in fact, their importance with respect to helping control insect populations, is considerable). Scorpions also act as natural gauges for environmental degradation. When scorpions cease to turn up in habitats that should support them, it is a strong indicator that the environment has been severely degraded. In this respect, scorpions act like “the canary in the coal mine” for natural habitats.

Very strangely, scorpions fluoresce under a UV light. They have fluorescent chemicals in their hyaline layer, part of the cuticle in their exoskeleton, that cause them to glow under ultraviolet light. I wonder what evolutionary advantage that offers scorpions? After I have slid away my telescope’s sun/dust shelter, I always flash my UV torch around to check that no scorpions have moved in under the brick pad on which the telescope stands. Thus far, none, but then I don’t observe barefoot or even in slip slops here, so it wouldn’t matter if they did anyway. I learnt my lesson about walking barefoot in the dark in scorpion territory on the night following the 2001 solar eclipse which I observed from the Kruger Park in Limpopo. I obviously gave a scorpion a hell of a fright nearly standing on it because it stung me not once but twice on my ankle; it was terrifically painful!

I like terrestrial scorpions; fascinating little creatures, their stings notwithstanding. But I adore the celestial scorpion beyond all measure! So seeing Scorpius rise just before dawn, I cannot wait for it to be back in our cold winter skies!