Datasets associated with: Late Holocene spread of pastoralism coincides with endemic megafaunal extinction on Madagascar

Recently expanded estimates for when humans arrived on Madagascar (up to
~10,000 years ago) highlight questions about the causes of the island’s
relatively late megafaunal extinctions (~2000-500 years ago). Introduced
domesticated animals could have contributed to extinctions, but the
arrival times and past diets of exotic animals are poorly known. To
conduct the first explicit test of the potential for competition between
introduced livestock and extinct endemic megafauna in southern and western
Madagascar, we generated new radiocarbon and stable carbon and nitrogen
isotope data from the bone collagen of introduced ungulates (zebu cattle,
ovicaprids, and bushpigs, n=66) and endemic megafauna (pygmy
hippopotamuses, giant tortoises, and elephant birds, n=68) and combined
these data with existing data from endemic megafauna (n=282, including
giant lemurs). Radiocarbon dates confirm that introduced and endemic
herbivores briefly overlapped chronologically in this region between 1000
and 800 calibrated years before present (cal BP). Moreover, stable isotope
data suggest that goats, tortoises, and hippos had broadly similar diets
or exploited similar habitats. These data support the potential for both
direct and indirect forms of competition between introduced and endemic
herbivores. We argue that competition with introduced herbivores, mediated
by opportunistic hunting by humans and exacerbated by environmental
change, contributed to the late extinction of endemic megafauna on
Madagascar.