An increasing number of prominent ethicists (McMahahn, Nussbaum) and effective altruists are advocating for 'wild animal suffering interventionism’ (WASI): that humanity has a strong duty to intervene into natural ecosystems to ameliorate wild animal suffering not caused by humans. Fulfilling this project requires intergenerational governance of all animal populations on earth and the development of powerful bio and surveillance technologies. These same technologies are also being developed for the purposes of ecological conservation. I argue that WASI and ecological conservation are fundamentally at odds as WASI must aim to eventually destroy ecosystems and wild animal populations. The nascent field of 'interspecies population ethics', posits that all moral subjects must be included in counterfactual populations, irrespective of species membership. I explore the population ethics accounts of McMahan, Parfit and O'Brien. This shows that WASI does not aim for a garden of Eden full of vast happy animal populations structured like natural ecological systems, as is claimed by WASI authors and their critics, but a world of (post)humans. This marks the encroachment of WASI into ecological conservation discourse as inherently anti-ecological. Emerging conflicts between WASI and conservationists are identified in New Zealand and Australia.
