Post-settlement extinction rates for the New Zealand avifauna

Post-settlement faunal extinction rates are widely cited statistics and help to understand the magnitude of recent biodiversity loss driven by human activity. However, extinction rate estimates can vary greatly depending on factors such as the geographic boundaries of the region being considered, how the faunal group is defined, completeness of fossil records, and taxonomic frameworks. Here, I combine recently described extinct bird species with the latest taxonomic revisions and well-defined geographic regions to provide an updated estimate of post-settlement extinction rates for the New Zealand avifauna. The results show that extinction rates varied regionally from 50% species extinction on the North Island to just 14.5% on offshore islands. As a whole, the New Zealand mainland and its offshore islands lost 30.9% of bird species, although this rate increases to 32.8% with the inclusion of the distinct Chatham Islands/Rēkohu avifauna.