he rarity of an organism is widely accepted as a good predictor of vulnerability, but rarity has been interpreted in a variety of ways. Rabinowitz et al. (1986) defined three dimensions of rarity for an analysis of the flora of the British Isles geographic distribution, habitat specificity, and local population size. They found the three factors to be independent, that is, each factor provides information not provided by the other two. In this paper, the method of Rabinowitz et al. is used to analyze the vulnerability of the cloud forest avifauna of the Cordillera Central of Colombia The method is extended by assigning a vulnerability index to each form of rarity and analyzing its taxonomic and ecological correlates.