This paper reviews empirical data and hypotheses from demographic, optimal foraging, life-history, community, and biogeographic theories to predict species sensitivity to habitat fragmentation. Twelve traits or trait groups are identified as potential predictors: population size; population fluctuation and storage effect; dispersal power; reproductive potential; annual survival; sociality; body size; trophic position; ecological specialization, microhabitat and matrix use; disturbance and competition sensitive traits; rarity; and biogeographic position. For each trait, the theoretical justification for its sensitivity to fragmentation and empirical evidence for its suitability as a predictor are discussed. Six of the twelve traits have strong empirical support as predictors: population size; population fluctuation and storage effects; competitive and disturbance sensitive traits in plants; microhabitat specialization and matrix use; rarity in the form of low abundance within a habitat; and relative biogeographic position. The remaining traits show few clear patterns when examined in isolation. Therefore, interactions between species traits and environmental conditions must be considered to predict species sensitivity to fragmentation. A classification of fragmentation sensitivity based on specific trait combinations is developed, and the implications of the results for ecological theory are discussed. The study highlights the importance of understanding species characteristics in relation to fragmentation and extinction, as species with similar realized niches and traits may behave similarly in response to environmental change. Functional types, based on these traits, can help reduce species diversity to operational entities for prediction and modeling. The paper aims to review hypotheses on predictors of species sensitivity to fragmentation, their theoretical basis, and empirical evidence.This paper reviews empirical data and hypotheses from demographic, optimal foraging, life-history, community, and biogeographic theories to predict species sensitivity to habitat fragmentation. Twelve traits or trait groups are identified as potential predictors: population size; population fluctuation and storage effect; dispersal power; reproductive potential; annual survival; sociality; body size; trophic position; ecological specialization, microhabitat and matrix use; disturbance and competition sensitive traits; rarity; and biogeographic position. For each trait, the theoretical justification for its sensitivity to fragmentation and empirical evidence for its suitability as a predictor are discussed. Six of the twelve traits have strong empirical support as predictors: population size; population fluctuation and storage effects; competitive and disturbance sensitive traits in plants; microhabitat specialization and matrix use; rarity in the form of low abundance within a habitat; and relative biogeographic position. The remaining traits show few clear patterns when examined in isolation. Therefore, interactions between species traits and environmental conditions must be considered to predict species sensitivity to fragmentation. A classification of fragmentation sensitivity based on specific trait combinations is developed, and the implications of the results for ecological theory are discussed. The study highlights the importance of understanding species characteristics in relation to fragmentation and extinction, as species with similar realized niches and traits may behave similarly in response to environmental change. Functional types, based on these traits, can help reduce species diversity to operational entities for prediction and modeling. The paper aims to review hypotheses on predictors of species sensitivity to fragmentation, their theoretical basis, and empirical evidence.