In this paper we document current research into new forms of public engagement presently taking place in UK biodiversity policy. This involves locating the main participants in such patterns of engagement; namely nature, amateur naturalists, and professional biologists and conservationists. Two interwoven and mutually interdependent perspectives or ‘imaginaries’—the ‘cartographic’ and the ‘ethnographic’—are presented in the paper to explore the shaping and interpretation of such new forms of engagement. However, in this context the interest lies in the ways in which either perspective is foregrounded or backgrounded by the different parties involved. The described shifts and movements of a range of actors and processes being studied demonstrate the fluidity and instability of networks of ‘knowing nature well’, whose stability is often assumed. The tracing of two constants—expertise and exchange—within networks inhabited by nature and by amateur and professional naturalists allows for an exploration of ways in which social/natural inclusions and exclusions occur in new participatory practices designed as part of biodiversity action planning.