Tibetan sacred mountains, the unique landforms influenced by the Buddhist religion in many Himalayan regions, are suggested to have great potential for preserving animal diversity. Yet, a bias might lie in evaluating the effectiveness of such areas, given the local culture of respect for, and protection of, wildlife, resulting in many animals that are relatively tame and, thus, easier to be detected visually compared with other regions. Here, we provide the first assessment of this issue, using Galliformes as a representative taxon on a typical Tibetan sacred mountain in western China. We estimated diversity of Galliformes relying on direct sightings versus an indirect technique of counting feathers, which avoids detectability issues associated with habitat and tameness of species. The data from direct sightings showed a higher relative abundance on the sacred mountain compared with its surrounding matrix, whereas the indirect technique of counting feathers suggested no considerable gains in species richness and abundance on the sacred mountain. Given the bias, we suggest that the biodiversity effects of Tibetan sacred mountains should be revisited. For management practices, we suggest that care will be needed to link Tibetan sacred mountains with conservation efforts. © 2019