The ability of low‐status protected areas under community management to achieve a conservation objective is frequently questioned, particularly in developing countries. The lack of sound, scientific‐based biodiversity monitoring frequently undermines attempts to evaluate the extent to which these areas are contributing to biodiversity conservation. Based on data collected between 2008 and 2010 in a Forest Reserve under community management in western Tanzania, our study tested fives methods: camera trapping, walking line transects, vehicle transects, opportunistic encounters and indirect signs, to find the most appropriate for future monitoring. Method comparisons confirmed a higher performance of camera trapping compared to other methods for the ability to detect species. However, our results identified the need of a better survey design to ensure a sound monitoring in the future. Besides method comparisons, our study provides the first fine‐scale data on mammal communities in such a low‐status protected area. Combined methods allow the identification of 49 species of medium and large mammals, a surprisingly high diversity for such area. These findings outline the potential conservation value of this type of protected area and call for better biodiversity monitoring throughout complexes of protected areas of different statuses and management regimes.