Diversity and extinction in Aepyornithidae

• Main Author: Hansford, James
• Other Authors: Trueman, Clive
• Published: University of Southampton 2018
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.759275

The Aepyornithidae are an insular radiation of giant birds from the late Quaternary of Madagascar which have been extinct for c. 1000 years. Complex and conflicting historical taxonomic hypotheses have limited study into these charismatic megafauna and they have been subject to little modern study in comparison to other avian megafauna and the mammalian megafauna of Madagascar. This thesis is the first modern study of Aepyornithidae to quantify the diversity and biogeography of skeletal remains in comparison to putative taxonomic hypotheses. Clarifying the convoluted history of historically proposed taxa underpins a modern framework for studying these enigmatic birds. A novel chronological sequence of high-quality radiocarbon dates provides the most reliable evidence for their species-specific extinction timings. Late survival of these birds contrasts markedly with rapid extinction processes observed in avian megafauna and presents an extended period of co-occurrence with human colonists suggesting complex and poorly understood interactions. Recording and dating evidence of butchery to modern osteological standards has provided unique and extraordinary evidence of human settlement 6000 years earlier than any other evidence suggests, and is the first verifiable information on direct impacts of butchery and hunting of Aepyornithidae. Dietary analysis demonstrates that these morphologically diverse species fulfilled different ecological niches, including extensive grazing behaviour in the central highlands. This promotes the need for new discussions into the pristine landscape of Madagascar, including more expansive investigations into aepyornithid ecosystem functions and the pre-human distribution of grassland savannah versus forested regions. It is hoped that this thesis will lead to novel research into Aepyornithidae and develop understanding of their role in defining the natural state of one of the worlds most threatened ecosystems.