Towards integrating interaction networks into global parasite conservation: insights from bats, bat flies and their fungal associates

Jonathan CAZABONNE , Danny Haelewaters, Aimée Blondelle, Melissa Ingala de Waal

Parasites are a key conservation blind spot. Even though parasitism is a widespread ecological lifestyle, most parasite diversity remains unknown, as do the interactions in which they are involved. Some parasite species are involved in multitrophic interactions, meaning they span multiple trophic levels. These complex interactions are generally understudied, and conservation frameworks fail to integrate them. The interaction network involving bats, bat flies, and bat fly-associated fungal parasites of the order Laboulbeniales provides a case study for identifying knowledge and conservation gaps in multitrophic interaction systems. In this chapter, we review the role of parasites and species interactions in conservation frameworks, as well as our current understanding of this tripartite parasitic and hyperparasitic system. We discuss gaps in species diversity and distribution (Linnean and Wallacean shortfalls), responses to abiotic environments (Hutchinsonian shortfall), ecological interactions across and within trophic levels (Eltonian shortfall), and the cascading consequences of host extinction on other partners in the interaction (Scarian and Ostromian shortfalls). We also discuss how species interactions, especially obligate ones, could be integrated into conservation schemes such as Red Listing, and we propose a simple conceptual framework to support this. Finally, we present outstanding questions and future directions, with the hope that they will foster collaborations and research in the field of multitrophic interactions, and contribute to a better understanding and protection of complex interaction networks in the face of global change.