Taxonomic work, conservation practice, and Red List assessments from the International Union for Conservation of Nature (IUCN) are intricately linked. The primary conservation goal for biodiversity consists of halting the factors that could lead to the local extinction of species. While many mammal surveys focused on establishing species checklists for each country, differences and changes in taxonomic names over time, compounded by a lack of research expertise and data mobilization, make it challenging to harmonize checklists and use this information in conservation practice. The objective of this article is to evaluate the role of regular taxonomic updates and data mobilization for mammals to support species conservation work. We reviewed the literature and recent field records (2009 – 2024) of the mammals of Rwanda, a country in East Africa. We compared them with the current IUCN Red List records for that country, complementing and validating species with further data from the Mammal Diversity Database (MDD). We identified 38 novel records of mammal species that need to be updated at the IUCN Red List to reflect their presence in Rwanda, including records upgraded to the species level from recent taxonomic publications. Following the gaps identified in the IUCN Red List, we highlighted how regular assessments and updates from scientists in the field of mammals can fill them, by updating scientific names and country legends. The IUCN should also strengthen collaboration with experts, duly track taxonomic changes, and ensure regular updates for the species assessment criteria and data. Such assessments will continue to provide data to rationalize timely updates and re-evaluations of species status, which will be most imperative for species tagged as Data-Deficient. We urge scientists to promptly update and disseminate similar findings on mammals, along with evidence-based records, to support conservation efforts. Our observations and recommendations should extend beyond the mammalian taxon and the country used as a case study.