Similar burrow architecture of three arid-zone scorpion species implies similar ecological function.
Many animals reside in burrows that may serve as refuges from predators and adverse environmental conditions. Burrow design varies widely among and within taxa, and these structures are adaptive, fulfilling physiological (and other) functions. We examined the burrow architecture of three scorpion species of the family Scorpionidae: Scorpio palmatus from the Negev desert, Israel; Opistophthalmus setifrons, from the Central Highlands, Namibia; and Opistophthalmus wahlbergii from the Kalahari desert, Namibia. We hypothesized that burrow structure maintains temperature and soil moisture conditions optimal for the behavior and physiology of the scorpion. Casts of burrows, poured in situ with molten aluminum, were scanned in 3D to quantify burrow structure. Three architectural features were common to the burrows of all species: (1) a horizontal platform near the ground surface, long enough to accommodate the scorpion, located just below the entrance, 2-5 cm under the surface, which may provide a safe place where the scorpion can monitor the presence of potential prey, predators, and mates and where the scorpion warms up before foraging; (2) at least two bends that might deter incursion by predators and may reduce convective ventilation, thereby maintaining relatively high humidity and low temperature; and (3) an enlarged terminal chamber to a depth at which temperatures are almost constant (±2-4 °C). These common features among the burrows of three different species suggest that they are important for regulating the physical environment of their inhabitants and that burrows are part of scorpions' "extended physiology" (sensu Turner, Physiol Biochem Zool 74:798-822, 2000).
Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel. amandaad@post.bgu.ac.il.|Department of Biology, Texas A&M University, College Station, TX, 77843, USA. amandaad@post.bgu.ac.il.
Amanda M
AM
Adams
Department of Entomology, National Museum of Namibia, Windhoek, Namibia.
Eugene
E
Marais
Department of Environmental and Forest Biology, College of Environmental Science and Forestry, State University of New York, Syracuse, New York, NY, 13210, USA.
J Scott
JS
Turner
Division of Invertebrate Zoology, American Museum of Natural History, New York, NY, 10024, USA.
Lorenzo
L
Prendini
Mitrani Department of Desert Ecology, Jacob Blaustein Institutes for Desert Research, Ben-Gurion University of the Negev, 84990, Midreshet Ben-Gurion, Israel.
Berry
B
Pinshow
D000818:Animals; D003889:Desert Climate; D004463:Ecology; D006813:Humidity; D007557:Israel; D009276:Namibia; D009425:Nesting Behavior / Q000502:physiology*; D012605:Scorpions / Q000502:physiology*; D013696:Temperature
Burrows; Extended organism; Scorpionidae; Temperature gradients; Three-dimensional modeling