Abstract
Aim Understanding extinction on islands is critical for biodiversity conservation. Introduced predators are a major cause of island extinctions, but there have been few large‐scale studies of the complexity of the effects of predators on island faunas, or how predation interacts with other factors. Using a large database of island mammal populations, we describe and explain patterns of island mammal extinctions as a function of introduced predators, life history and geography. Location Three hundred and twenty‐three A ustralian islands. Methods We built a database of 934 island mammal populations, extinct and extant, including life history and ecology, island geography and the presence of introduced predators. To test predictors of extinction probability, we used generalized linear mixed models to control partially for phylogenetic non‐independence, and decision trees to more fully explore interactive effects. Results The decision trees identified large mammals (> 2.7 kg) as having higher extinction probabilities than small species ( Main conclusions Island mammal extinctions result from complex interactions of introduced predators, island geography and prey biology. One conservation implication of our results is that eradication of introduced apex predators (cats, foxes or dingoes) from islands could precipitate the expansion of black rat populations, potentially leading to extinction of native mammal species whose remaining populations are confined to islands.