The lack of wildlife health (WH) surveillance systems leaves critical gaps in biodiversity conservation and One Health protection. Integrating rangers patrolling protected areas (PAs) into WH monitoring represents a cost-effective and scalable opportunity to address these gaps at key human–wildlife interfaces and nature strongholds. For the past 2.5 years, organizations across 4 countries have collaborated to pilot this integration. The approach involved establishing a practical definition of health event for rangers patrolling PAs, developing a referential form tailored for rangers to document these events, training key country actors to identify and record health events on this form, merging this form with local forms used by rangers to record other events of interest observed during their patrols (e.g., illegal logging), and training rangers to identify and document health events with the modified local form. We examined 4 case studies involving dozens of PAs in different countries with different languages and local partners. The recording of health events was supported by the Spatial Monitoring And Reporting Tool, SMART, which provides the modified form for rangers on mobile devices and enabled standardized recording of events. Currently, over 200 rangers across more than 50 PAs have been trained, and more than 1000 health events have been recorded. This provides early evidence that rangers could enhance WH monitoring and strengthen biodiversity conservation, ultimately fostering One Health. This initiative lays important groundwork for overcoming key barriers (e.g., lack of personnel and funding) to establishing functional WH surveillance systems in PAs. Still, specific data infrastructure, human resources, and institutional support are needed. It will be important to evaluate the limitations of ranger-collected data and align monitoring goals with the capabilities of rangers and data managers. Expansion to additional PAs is planned, alongside efforts to integrate ranger-collected data into multisectoral One Health frameworks.
