Species: a praxiographic study Eben Kirksey UNSW Australia/Princeton University Taxonomists, who describe new species, are acutely aware of how political, economic, and ecological forces bring new forms of life into being. Conducting ethnographic research among taxonomic specialists – experts who bring order to categories of animals, plants, fungi, and microbes – I found that they pay careful attention to the ebb and flow of agency in multispecies worlds. Emergent findings from genomics and information technologies are transforming existing categories and bringing new ones into being. This article argues that the concept of species remains a valuable sense-making tool despite recent attacks from cultural critics. Multispecies ethnography contains a hidden ontology lurking within: that of ‘species’ (Kirksey & Helmreich 2010: 563). John Dupr´ e(1992), a philosopher of science, suggests that the concept of a species gives rise to two principal questions: Is a species a natural kind that exists in nature independently of its discovery, or naming, by humans? Is an individual organism to be assigned to a particular species on the basis of morphological characteristics, reproductive links, evolutionary heritage, or some other features? Donna Haraway regards the idea of a species as a lovely oxymoron, ‘always both logical type and relentlessly particular’ (2008: 164). Building on this conversation, I will argue for the utility of ‘species’ as a valuable sense-making tool. Evidence in support of this argument will come from ethnographic research among taxonomic experts working in diverse branches of the tree of life. This article addresses a number of related questions: Where do species exist? How are species enacted? What practices bring species into being? Annemarie Mol has described ‘praxiography’ as a method to ‘stubbornly take notice of the techniques that make things visible, audible, tangible, knowable’ (2002: 33). Praxiography involves the practicalities of doing disease, according to Mol’s original study, The body multiple: ontology in medical practice. ‘The disease’ is never alone, by Mol’s reckoning. It does not stand by itself. ‘It depends on everything and everyone that is active while it is being practiced’ (2002: 32). Departing from Mol, I ask: Can a species ever be alone; can it stand by itself? Do species depend on other beings, things, and apparatuses that are active in producing their existence? Do biologists just make species; do they simply construct them? Or are multiple agents involved in their Journal of the Royal Anthropological Institute (N.S.) 00, 1-23 C  Royal Anthropological Institute 2015