A 2011 Strontium isotope study of "P. robustus" teeth from the dolomite Sterkfontein Valley found that, like other hominins, but unlike other great apes, "P. robustus" females were more likely to leave their place of birth (patrilocal). This also discounts the plausibility of a harem society, which would have resulted in a matrilocal society due to heightened male–male competition. Males did not seem to have ventured very far from the valley, which could either indicate small home ranges, or that they preferred dolomitic landscapes due to perhaps cave abundance or factors related to vegetation growth.