Human activities are degrading ecosystems worldwide, posing existential threats for biodiversity and humankind. Slowing and reversing this degradation will require profound and widespread changes to human behaviour. Behavioural scientists are therefore well placed to contribute intellectual leadership in this area. This Perspective aims to stimulate a marked increase in the amount and breadth of behavioural research addressing this challenge. First, we describe the importance of the biodiversity crisis for human and non-human prosperity and the central role of human behaviour in reversing this decline. Next, we discuss key gaps in our understanding of how to achieve behaviour change for biodiversity conservation and suggest how to identify key behaviour changes and actors capable of improving biodiversity outcomes. Finally, we outline the core components for building a robust evidence base and suggest priority research questions for behavioural scientists to explore in opening a new frontier of behavioural science for the benefit of nature and human wellbeing.We are grateful for funding from the Cambridge Conservation Initiative Collaborative
Fund and Arcadia, RSPB, and the Gund Institute for Environment, University of Vermont. AB is supported by a Royal Society Wolfson Research Merit award. EEG was supported by a NERC studentship, grant number NE/L002507/1. We thank Paul C. Stern for helpful discussion and feedback
