Nature does more for us than simply provide tangible goods and services. In fact, if you look closely enough, it has the chance to marvel even the most sceptical of us. Scorpions can provide this wonder, not only as one of the most unique and magnificent creatures on earth but also through a hidden component seldom seen by humans – their home.
Apart from the fact that they are also among the most feared, scorpions are rather misunderstood animals but nonetheless give architects something to think about.
Scorpions are ancient arthropods that were once aquatic but became terrestrial about 420 MYA. On land they inhabited a great array of major habitats and are thus considered among the most widely distributed animals on earth. They are perfectly adapted for the dry (semi) desert conditions. Scorpions are found on all continents except Antarctica with over 1500 species worldwide.
Scorpions use one of three ways to survive in their respective environment; living in trees, wondering scorpions that shelter under logs or rocks and burrowing scorpions. A group of burrowing scorpions also referred to as fossorial scorpions create burrows in soft substrates such as sand and fine gravel although occasionally they also construct their burrows in hard substrates such as clay and calcrete soils. What looks merely like an obscured dome shaped entrance to the casual passerby in fact turns into an underground architectural master piece.
Martin Handjaba, a researcher and Masters Student based at the Gobabeb Research and Training Centre in the Namib Desert from the Namibia University of Science and Technology (NUST) is interested in how scorpions survive in their subterranean palaces. Carbon dioxide and ammonia concentration can reach lethal amounts in burrows depending on the soil type, size of the animal and local biophysical factors. Together with a group of researchers from the Ben Gurion University of the Negev, Martin used ordinary resin to make casts of the burrows; the researchers discovered the incredible 3D blueprints that make up each unique dwelling. This architecture differed with respect to soil type, but seemed to show a consistent compartmentalisation of “rooms” across all burrows.
The visible single hole shortly winds either left or right creating spirals following a very sophisticated design. The burrows then turn sharply downwards, descending further below ground to form a dead-ended chamber. Being cool and humid, this chamber provides a refuge for the scorpions to rest during the heat of the day, where evaporative water loss is minimal. As the various burrow compartments were similar to those observed in all other burrows studied worldwide, this suggests that burrow building in scorpions has evolved by natural selection to meet the animals’ physiological needs.
The discovery of this curious burrow architecture raises even more questions about the physiological adaptations of burrowing scorpions in the world, while also providing a crucial baseline for understanding the relationship between these structures and the scorpion environment – a matter especially pressing with the continued acceleration of global climate change. Future Research will seek to address if these magnificent creatures are able to cope in their burrows on an ever warming planet. (Photo credit: Oliver Halsey and Martin Handjaba)