Selecting umbrella species as mammal biodiversity indicators in tropical forest

Conservation managers often monitor umbrella species as indicators of broader biodiversity patterns, but this assumption is seldom evaluated due to lack of survey data and objective umbrella criteria. We evaluated the performance of eight candidate umbrella species in representing broader patterns of mammal biodiversity in Sumatra, Indonesia, using a comprehensive camera trap dataset from the island's largest remaining tropical rainforest. We employed an occupancy modeling framework to quantify the association between species-level occupancy and four community-level biodiversity parameters while accounting for imperfect detection. Sambar deer and clouded leopard were consistently ranked the top umbrellas. Areas where these species were prevalent were associated with higher levels of community occupancy, species richness, functional and phylogenetic diversity. Sumatran tiger and rhino were among the lower ranked umbrellas, and inadequately represented other biodiversity parameters despite being the main subjects of monitoring. Our results demonstrate that the occurrence status of charismatic species commonly regarded as umbrellas does not necessarily represent broader patterns of biodiversity. Species that are frequently overlooked by conservation decision-making may better represent overall mammal diversity. We advocate utilizing umbrella fleets with multiple species monitored to better represent biodiversity patterns, and encourage broader application of our data-driven framework to assess umbrella species performance.