Data and code for Hurtado et al. 2024 - Generalism in species interactions is more the consequence than the cause of ecological success

Generalism in species interactions is more the consequence than the cause of ecological success

Pilar Hurtado, Gregorio Aragón, Marina Vicente, Bo Dalsgaard, Boris R. Krasnov & Joaquín Calatayud

Generalism in resource use is commonly considered a critical driver of population success, species distribution, and extinction risk. This idea can be questioned, as generalism may be a result, rather than the cause, of species abundance and range size. We test these contrasting causal hypotheses focusing on host use in three databases encompassing ~44.000 mutualistic (hummingbird-plant), commensalistic (lichen-plant), and parasitic (flea-mammal) interactions in 617 ecological communities across the Americas and Eurasia. Across all interaction types, our analyses indicate that range size and abundance influence the probability of encountering hosts and set the arena for species to express generalism potentials or adapt to new hosts. Hence, our findings support the hypothesis that generalism is a consequence of species ecological success. This highlights the importance of ecological opportunity in driving species characteristics considered key for their survival and conservation.