Anticipating endangerment

The last two decades have witnessed an explosion of national and global lists of threatened and endangered species. This article draws on interviews with prominent list managers and observations of their assessments to explore the scientific practices of list-making in the context of species conservation. Delving into the complex calculations of risk and threat that take place in the process of ranking non-human species based on their probability of extinction, the article explores the threatened species list as a biopolitical technology of catastrophe governance. My focus on two prominent lists-the IUCN Red List of Threatened Species and NatureServe's assessment system-illuminates various characteristics of futuristic governance through the threatened species list, including its properties as a list-database hybrid and as a barometer of life. I also explore the biopolitical regime of ranking life and its focus on species, its governing of direct ( human) threats and the nature-culture binary that this promotes, its status as scientific and apolitical and its aspiration for global reach, and the "species experts'' versus "threat experts'' divide that underpins its operations. The article concludes with a discussion on the effects of the lists' increasing automation and algorithmization, as seen from the perspective of the lists' managers. The lists' "threat calculator'' in particular quantifies and projects present and future threats to non-human species, using fuzzy numbers, ordinal scales, and open standards to anticipate and prevent the forthcoming Sixth Extinction.