Understanding the interplay between rarity and vulnerability in the decline and extinction of species is a major challenge for modern conservation biology. In addition to traditional approaches, answering this question necessarily requires integrating new methodologies and information on species' life-history traits and responses to environmental stressors. Here we use data for over 4000 mammal species to: (1) assess which forms and levels of rarity are most represented across current IUCN threat categories; (2) test whether interspecific variation in vulnerability is more closely linked to intrinsic traits related to their rarity, or to extrinsic factors related to anthropogenic pressures; and (3) identify geographical areas where species with high potential vulnerability are particularly common and assess their overlap with forecasts of land cover change. To achieve these goals, we model the directional influence of life-history traits related with rarity and extrinsic correlates on vulnerability. Our results confirm the strong link between rarity and vulnerability within mammalian orders. A model encompassing the three main rarity traits (i.e. range size, population density, and habitat breadth) correlates with vulnerability, despite not being directly correlated with population density. Recent habitat changes (within the past 35 years) did not show a direct relationship with vulnerability, but the contractions in range size reveal a more complex long-term effect on species vulnerability. Given the current scenario of limited conservation resources, we anticipate that knowledge about the characteristics most associated with vulnerability, coupled with mapping species possessing these traits and facing potential future land changes, can facilitate the development of more precise and effective conservation strategies aimed at preventing species extinctions.