The price of path: do snake roadkills in Colombia reflect phylogenetic trends and relate to functional traits?

Roads are essential infrastructure for human development. However, they generate strong ecological impacts and represent a growing threat to wildlife populations by causing the death of millions of wild animals each year. Snake mortality from roadkill is of particular concern because snakes play fundamental ecological roles and yet remain poorly studied from both ecological and evolutionary perspectives, especially in Neotropical countries. In this study, we evaluated the association between snake roadkill records in Colombia and certain functional traits, while accounting for their phylogenetic relationships. To do so, we compiled records from databases, collections, and literature, calculated values of evolutionary distinctiveness (ED) at both global and national scales, estimated the potential loss of phylogenetic diversity (PD), and assessed the presence of phylogenetic signal in the incidence and occurrence of roadkill. We employed Phylogenetic Generalized Least Squares (PGLS) and Phylogenetic Generalized Linear Models (PGLM) to evaluate the relationship between functional traits (e.g., body length, coloration, microhabitat, activity pattern, and distribution range) at two levels: species recorded as roadkilled and the entire set of snake species present in the country. We found 1,301 roadkill records for 94 species, mainly from the families Colubridae and Boidae, representing a PD = 2.007 Ma (41% of the national PD = 4.865 Ma). At the level of species recorded as roadkilled, no phylogenetic signal or association with the evaluated functional traits was detected, although the number of records increased with broader distribution ranges. On the other hand, considering all snake species present in the country, roadkill incidence was higher in those with conspicuous coloration, larger body size, and broader distribution ranges.