Setting conservation priorities within monophyletic groups: An integrative approach

Species differ in their need for conservation action and in their relative importance for conserving current and historic ecological and evolutionary diversity. Given the present biodiversity crisis and the lack of resources, threatened species must be differentiated from each other so that those presenting higher conservation priority can be attended first. Here we propose a novel approach to calculate a priority index (PI) for species within monophyletic groups, by combining life history traits, extrinsic factors, ecological singularity, and phylogenetic distinctness. To test our approach we used a group of Neotropical snakes, the pseudoboines, as our model lineage. To create the PI we combined four different indices: intrinsic vulnerability to extinction (IVE, comprised by six factors), extrinsic vulnerability to extinction (EVE, comprised by three factors), ecological oddity (EO, four factors) and phylogenetic distinctness (PD). Intrinsic vulnerability to extinction was evenly distributed across the clade and EVE was higher in species present in the Brazilian hotspots of Biodiversity, Atlantic Forest and Cerrado. As expected due to the nature of the index, a few species that differ from the average phenotype presented high EO values, whereas PD values did not vary greatly among pseudoboines. Representatives from almost all clades within the pseudoboines appear among the ten highest PI values, maximizing the phylogenetic diversity of the prioritized taxa. Although it is not possible to compare values obtained in studies to different lineages (indices are clade-specific), extending this approach to more inclusive lineages (e.g., families) might enhance the quality of future prioritization processes. The method we propose would be especially useful for taxonomically driven conservation action plans.