Biodiversity across the world is significantly threatened, with tropical regions especially impacted. Over the past 30 years, over 40% of mammalian habitats have been lost due to human activity. Protecting biodiversity is a primary goal for conservationists but surveying entire ecological communities to evaluate the impact of human activities and conservation efforts requires significant resources, which are often scarce. In order to simplify community monitoring and maximize limited resources, conservationists use umbrella species.

Umbrella species are animals whose protection is believed to indirectly protect other species sharing their same habitat. Animals requiring expansive, diverse habitats are chosen as their territory overlaps with many other species. They serve as proxies for experts to measure the entire ecosystem’s health without having to track every single species. Substantial funding is then directed towards these prominent species rather than broader ecosystem conservation.

Despite its appeal and worldwide use, the umbrella species approach is considered imperfect and its effectiveness is uncertain. Monitoring even a single species in a community is expensive and difficult, especially for elusive animals like tigers. Often, there is inadequate data to support the assumption that an umbrella species’ needs and presence accurately reflect the health of the entire ecosystem and the needs of other species. Single-species monitoring risks ignoring key players in an ecosystem’s network and the specific threats faced by diverse species, leading to incomplete and sometimes misguided conservation programs.

Another flaw of the umbrella species concept is the lack of objective criteria for choosing a species. Large, charismatic mammals are often selected for their ability to attract public and political support, rather than for their ecological significance. This can overlook animals that have crucial ecological roles but less notoriety. 

Another challenge in identifying strong umbrella species is that most evaluations focus only on a single measure of biodiversity, which can lead to inaccurate conclusions about an ecosystem’s functioning. This not only misinforms us, but can also misdirect conservation goals. For example, species richness counts the number of species in an area but doesn’t distinguish between native and non-native species. High species richness might hide serious threats like invasive species or low functional diversity. Multiple parameters are fundamental as they also help predict how resilient an ecosystem is to change. Functional diversity, which examines the specific roles animals have in their environments, shows how well it can maintain its functions under stress. Phylogenetic diversity, which explores the evolutionary relationships between species, reveals an ecosystem’s potential for adaptation. 

The authors evaluated umbrella species candidates to identify the best representatives for mammal biodiversity in Sumatra, Indonesia. To gather information, the authors deployed 212 camera traps across several forest types and elevations in the Leuser Ecosystem, a 25,000 km² tropical forest in northern Sumatra. While 75% of the area is designated for conservation, much of it is still negatively affected by agriculture, roads, and settlements. The cameras collected data on medium to large mammals from May 2016 to March 2018, each active for an average of 85 nights, totaling 18,102 nights of recording.

The analysis focused on eight candidate species that were selected based five criteria: well-known natural history, large home range, management needs, moderate sensitivity to human disturbance, and ease of sampling. These species included: 

• Sumatran tiger 
• Sumatran rhinoceros
• Sambar deer
• Clouded leopard 
• Sun bear
• Dhole
• Mountain serow
• Sumatran hog badger

Of these, only the Sumatran tiger and rhinoceros were actively umbrella species at the time of this study. 

The researchers measured and ranked each candidate’s performance across four biodiversity parameters: community-level occupancy, species richness, functional diversity, and phylogenetic diversity. Community-level occupancy refers to how many species from the community were present across multiple locations. 

The study revealed that the Sumatran tiger and rhinoceros poorly represent the broader mammal community in Sumatran forests. This is despite these species receiving substantial funding because they were believed to be strong umbrella species. It’s possible that their ability to perform in the analysis was hindered because their populations have been decimated by hunting. Among the eight candidate species evaluated, the sambar deer, clouded leopard, and sun bear emerged as the highest-performing umbrella species. 

The sambar deer was the best indicator of community occupancy and functional diversity, with the clouded leopard ranked second in these parameters. Of the species in the study, only the sambar deer and clouded leopard had a significant positive impact on community phylogenetic diversity. The sun bear best indicated an area’s species richness. 

It’s important to note that while this was a vast survey, the cameras struggled to detect small and arboreal mammals, like squirrels. These species, and the roles they play in the Leuser Ecosystem, may have been underrepresented in the study. 

Overall, these results demonstrate that no single animal can represent all aspects of biodiversity, or the needs of all other animals in an area. The authors recommend using multiple species — an “umbrella fleet” — as a practical alternative to full community studies. This not only preserves precious conservation resources, but ensures that a wider area is monitored to meet the needs of as many species as possible. Advocates are encouraged to support and promote conservation programs that focus on preserving entire ecosystems rather than single, charismatic species.