Ecological Character Displacement in a Lizard

Two species of subterranean skinks (Typhlosaurus) are sympatric in part of the southern Kalahari Desert. The geographic range of the smaller species (T. gariepensis) is entirely included within that of the larger one (T. lineatus). Snout-vent lengths, head dimensions, proportional head lengths, and prey size of T. lineatus are larger in sympatry than in allopatry. Morphological and dietary evidence support the hypothesis that behavioral and morphological character displacement has occurred in female and immature T. lineatus, which reduces dietary overlap with T. gariepensis. Dietary data for male T. lineatus may be conflicting.