Taxonomic bias towards charismatic and easy-to-find mammals shapes knowledge of parasites

Research efforts are unevenly spread across the tree of life, with cascading effects on the knowledge of the different facets of biodiversity. While taxonomic bias for vertebrates is well known, whether and how it scales down to the knowledge of their parasites is unknown. Here, we map research effort on parasites across mammals using a comprehensive search of the Web of Science database. Then, we formulate several hypotheses based on known general drivers of taxonomic bias at the host level, and test predictions concerning the amount of research across mammals using Bayesian Generalized Linear Mixed Models accounting for phylogenetic relationships. Knowledge of parasites was better for mammals with large body size, described a long time ago, occurring in captivity, having a broad niche and a large range encompassing human-dominated regions. These factors are likely proxies of: (i) preference towards charismatic hosts (e.g., body size), and: (ii) the likelihood of finding a host (e.g., range size, habitat breadth, human population density in the species’ geographic range, occurrence in captivity). Our findings suggest that specific mammal groups have been under-explored from a parasitological perspective (notably rodents and bats), providing information for targeted research and resource allocation. This study shows avenues for investigating the diversity of parasites, largely unexplored but whose knowledge is essential to preventing zoonotic disease transmission and understanding ecological systems.