Meeting Abstract
Many animals spend much of their time underground in burrows that serve as refuges from predators and adverse environmental conditions. The intimate association between animal and burrow leads to the question ‒ how has burrow architecture been shaped by natural selection on the builder? We used the burrows of scorpions to test the idea that burrow structure is an extension of the organism’s physiology, regulating the temperature and moisture levels of its surroundings. Specifically, we predicted that scorpion burrows are built to minimize convective ventilation of the burrow air space. This may maintain high relative humidity in the burrow, thereby reducing the scorpion’s evaporative water loss. We made aluminum casts of natural burrows of two species, one from Israel, Scorpio maurus palmatus (N = 20), and one from Namibia, Opistophthalmus setifrons (N = 4). We quantified burrow shapes and dimensions with 3D scans of the casts. Opistophthalmus setifrons had more tortuous (p = 0.001) burrows, but burrow depths were not significantly different between species. All burrows had in common a horizontal platform just below the surface, apparently for the scorpion to warm before emerging to hunt after dark. All burrows descend with at least two bends, to a depth where there is little diurnal temperature fluctuation, and terminate in a humid chamber. Our findings demonstrate how an ectothermic arthropod may modify its environment to serve its behavioral and physiological needs.
