Drought Coincided with, but Does Not Explain, Late Holocene Megafauna Extinctions in SW Madagascar

Climate drying could have transformed ecosystems in southern Madagascar during recent millennia by contributing to the extinction of endemic megafauna. However, extent regional aridification past 2000 years is poorly known, as are responses animals and economically important livestock drying. We inferred ~1600 climate change around Lake Ranobe, SW Madagascar, using oxygen isotope analyses monospecific freshwater ostracods (Bradleystrandesia cf. fuscata) elemental lake core sediment. changes habitat diet introduced extinct megaherbivores bone collagen stable 14C datasets (n = 63). Extinct pygmy hippos multiple giant lemur species disappeared from vicinity Ranobe a dry interval ~1000–700 cal yr BP, but simultaneous appearance cattle, high charcoal concentrations, other evidence human activity confound inference drought-driven extirpations. Unlike megafauna, relatively low nitrogen values among cattle suggest they survived intervals exploiting patches wet habitat. Although megafaunal extirpations coincided with drought coupled data sediments do not support hypothesis that megafauna populations collapsed solely because drought. Given reliance on mesic will become more face projected drying, we argue sustainable conservation spiny forests should local livelihoods ensuring zebu access Additionally, current interactions between pastoralism riparian habitats be studied help conserve island’s biodiversity.