Biogeochemical evidence for targeted landscape use in ancient foragers of Malawi

The Zambezian Biome of southern-central Africa was an important environmental setting for ancient human interactions and biogeographic dispersals. Here, we assess herbivore migratory behavior and habitat selection with a ~ 2,500 km2 isoscape of bioavailable strontium (87Sr/86Sr) for the Kasitu Valley of northern Malawi, and a probabilistic spatial assignment of fossil herbivore enamel from four sites dated to the last 25,000 calibrated years BP. The results show a very large range in bioavailable 87Sr/86Sr values in the study area (0.7248-0.8521) and reveal that foragers hunted small game locally and procured most large prey in the Afromontane grasslands to the southeast of the study area and along narrow riparian corridors. We found no evidence of migratory behavior in species that exhibit this behavior today. Ancient foragers likely hunted prey that were available year-round, consistent with zooarchaeological and genetic evidence for reduced mobility at the end of the Pleistocene. Foragers hunted small game locally and procured most large prey in riparian habitats and Afromontane grasslands to the southeast of the Kasitu Valley of northern Malawi, suggesting that migratory behavior in large grazers was absent, according to strontium isotopic analysis.