Decision science and the conservation of biological diversity

Despite major advances in the conservation of biological diversity, a persistent implementation gap remains: robust scientific evidence often fails to translate into effective management action. In this keynote, I will explore how decision science can help bridge that gap by providing a transparent framework for turning knowledge into action. I will present decision science as a formalization of common sense—an iterative, values-driven approach that breaks complex conservation challenges into clear objectives, alternative actions, and explicit predictions about outcomes.

Drawing on two case studies, I will illustrate how decision science improves conservation outcomes by clarifying objectives, evaluating trade-offs, and reducing uncertainty. The first example, the Mauritius echo parakeet (Psittacula eques), highlights the crucial distinction between fundamental and means objectives. Intensive nest biosecurity successfully reduced disease prevalence, yet unexpectedly diminished fledging success, demonstrating how management can become fixated on intermediate targets while losing sight of fundamental goals. In the second case study, the recovery project for the Mauritius olive white-eye (Zosterops chloronothos) illustrates how decision science can support strategic learning and overcome risk aversion. By combining experimental management with cost-effectiveness and stochastic dominance analysis, managers demonstrated that a less expensive supplementary diet not only reduced costs but also represented the lower-risk option when uncertainty was fully considered.

Together, these examples demonstrate how decision science provides a rational, transparent, and defensible process for allocating scarce conservation resources. In an era of accelerating biodiversity loss and growing resource constraints, integrating decision science into conservation practice offers a powerful pathway for closing the implementation gap and improving the effectiveness of biodiversity conservation worldwide.