Records of the Western Australian Museum Supplement 78 A Biodiversity Survey of the Pilbara Region of Western Australia, 2002 – 2007 edited by A.S. George, N.L. McKenzie and P. Doughty Records of the Western Australian Museum, Supplement 78: 271–284 (2010). Spatial distribution patterns of scorpions (Scorpiones) in the arid Pilbara region of Western Australia Erich S. Volschenk1,3, Allan H. Burbidge2, Bradley J. Durrant1,2 and Mark S. Harvey1 1 Department of Terrestrial Zoology, Western Australian Museum, Locked Bag 49, Welshpool DC, Western Australia 6986, Australia. 2 Department of Environment and Conservation, PO Box 51, Wanneroo, Western Australia 6065, Australia. 3 Subterranean Ecology Pty Ltd, Suite 8/37 Cedric Street, Stirling, Western Australia 6021, Australia. Email:
[email protected] Abstract – We sampled scorpions in a systematic survey of 294 sites representing the major landform types across the arid Pilbara region of north-western Australia, an area of ca. 179,000 km2. We trapped two species of Isometroides, 10 of Lychas and 10 of Urodacus. All species were undescribed except one (U. megamastigus). Patterns of occurrence were similar to those found previously in arid Western Australia, in that temperature and soil characteristics seem to influence scorpion distributions; however, there were only weak correlations between species richness and sandiness of the soil, water availability, and annual temperature. In a classification of the sample sites based on occurrence of scorpion species, the major division in the dendrogram was associated with topographic and soil variables, while annual temperature, soil depth, ruggedness, total K and the presence of Acacia species were the five variables (of the 25 available) providing the best fit with the site matrix.