Simultaneous extinction of Madagascar's megaherbivores correlates with late Holocene human-caused landscape transformation

Reconstructing the dynamics and drivers of late Quaternary megafaunal extinctions requires direct radiometric date series that are assessed within probabilistic statistical frameworks. Extinction chronologies poorly understood for many tropical regions, including Madagascar, which had a diverse, now-extinct Holocene large vertebrate fauna “megaherbivore” guild endemic hippopotami elephant birds. Madagascar's megaherbivores likely played vital roles in regulating ecosystem structure nutrient cycling, but few dates available megaherbivore specimens identified to species level, with uncertainty over when why different representatives this disappeared. Here, we conduct new investigation into Malagasy extinction dynamics, 30 AMS 63 audited published dates. We use Gaussian-resampled inverse-weighted McInerny (GRIWM) analysis estimate species-specific three bird (Aepyornis hildebrandti, Mullerornis modestus, Vorombe titan), eggshell representing Aepyornis or Vorombe, two hippo (Hippopotamus lemerlei, H. madagascariensis), communities biomes. Megaherbivores persisted millennia after first human arrival. estimates vary significantly between biomes, disappearance from dry deciduous forest millennium earlier than other possibly reflecting local variation population densities pressures. However, all elsewhere across Madagascar until ?1200-900 bp, they collapsed suddenly. Extinctions closely correlated time intensive conversion forests grassland at ?1100-1000 probably associated shift agro-pastoralism radical change sustainability prehistoric interactions biodiversity.