Status, trends, and conservation priorities for the world's mammals

Mammals continue to face increasing extinction risk, largely driven by escalating human pressures. We analyzed changes in extinction risk for 4,992 mammal species assessed by the IUCN Red List of Threatened Species using an ordinal modelling framework (Cumulative Link Mixed Models) to test the correlation between biological traits, ecological characteris-tics, anthropogenic threats, and trends over time. Since 1996, most species remained sta-ble, but extinction risk increased by ~9% and decreased by <1% of the mammals. Deteriora-tions in extinction risk were most pronounced in the Indomalayan, Afrotropical and Australa-sian realms, and in several taxonomic groups, particularly Primates. Changes were strongly structured at the genus level, indicating shared trends among related taxa. Near threatened species had the highest probability of deterioration (9.3%), highlighting this category as a critical early warning stage. Exposure to a very high number of threats was the strongest pre-dictor of deterioration; conversely, species benefiting from multiple conservation actions were more likely to improve than deteriorate, suggesting that targeted interventions may con-tribute to reducing extinction risk. Habitat generalists also showed greater chances of im-provement. Most intrinsic traits showed limited influence on category change, except for trophic level, with generalist feeders less at risk. Overall, our results show that mammal ex-tinction trajectories are primarily shaped by the number of threats a species faces and its bi-ogeographic context, and further demonstrate the need for a considerable scaling up of con-servation efforts, including for species that have not yet reached the highest categories of threat.