Can Charismatic Megafauna Be Surrogate Species for Biodiversity Conservation? Mechanisms and a Test Using Citizen Data and a Hierarchical Community Model

Charismatic megafauna are a conservation concern and a flagship of conservation for many other species in the practice of biodiversity conservation. However, some studies support the roles of charismatic megafauna while others do not. In this chapter, we review the ecological mechanisms of why charismatic megafauna can be surrogate species. Based on the niche theory, specialist charismatic species, such as umbrella species, are likely to be surrogate species for richness or abundance of specialist species sharing the same niche axis. Citizen data are promising for testing this hypothesis; however, they are usually collected in a spatially biased manner, which hampers their usage. Here we analyzed citizen data with a hierarchical community model accounting for sampling processes and mapped Hokkaido bird species richness at different resolutions. By overlaying these maps with the distributions of Blakistons fish owl and red-crowned crane breeding sites, we show that these sites had higher forest or grassland/wetland bird species richness. Furthermore, the surrogacy was scale-dependent. Conservation practices entail social costs, and continued focus on the role of surrogate species would be due to public understanding and support being prerequisites for their implementation. We advocate selecting species with charismatic features and umbrella roles or flagship-umbrella species, given the strengths and limitations of surrogate schemes, as they play prominent roles linking biodiversity conservation and society.