Generating evidence from both successes and failures of conservation interventions is critical for improving our capacity to learn how to design, deliver, evaluate and improve such initiatives. This is particularly imperative for highly-threatened and highly-valued species such as Critically Endangered black rhinoceros, which attract large investments of resources and present a high risk of extinction. The systematic generation and assessment of evidence on what methods and mechanisms work, which do not, and under what circumstances is often poorly described and implemented. We present a synthesis of learnings from more than a decade of designing, delivering, evaluating and improving community-based ranger programs in north-west Namibia. We illustrate how adopting an iterative process tracing methodology to generate evidence that enables teams to track and improve their performance over time can provide a foundation for a collective knowledge bank, an enhanced learning process, and tangible conservation outcomes. We illustrate how harnessing the values of key local participant groups in program design can lead to delivering measurable intermediate results along pathways for engaging local leadership, empowering rangers, and creating income-generating opportunities that, in our case, contributed to a more than 90% reduction in illegal hunting of black rhinoceros. These results manifest with minimal use of conventional militarized law enforcement anti-poaching mechanisms suggesting that, at least in our situation, investing resources into improving the alignment between the value local people attach to protecting rhinoceros and the ways in, and degree to, which a protection programme manifests these values, is an effective, ethical, cost-efficient and socially just strategy. We offer lessons learned synthesized as a mnemonic to "LIVEN" up ranger program to be more locally inclusive and collaborative. Employing fit-for-purpose evaluation methodologies that are focused first and foremost upon internal team learning has become our guiding principle.