The observed and expected genotype proportions at each microsatellite locus were tested for deviation from Hardy–Weinberg expectations in each population. There was no significant departure from Hardy–Weinberg equilibrium at any locus in either of the Strzelecki Ranges, Eyre Peninsula or Mt Lofty Ranges populations. However, a significant heterozygous deficit at Phc-1 (P = 0.001) and a heterozygous excess at Phc-11 (P = 0.001) in the Kangaroo Is. population were observed. Deviations from Hardy–Weinberg equilibrium were more than would be expected owing to chance alone, and may indicate non-random mating due to sampling across demes in disjunct localities throughout this large island.