Background and Aims: Conservation efforts require a rational basis for taxa prioritization; it is essential to recognize the evolutionary independence of units, typically recognized as species. Because different criteria on species limits lead to different conservation assessment priorities, conceptual problems limit the possibility to accurately assess the conservation status that species are undergoing to protect them effectively.

Methods: We analyze the implications of using the phylogenetic species concept (PSC) in the risk categories determination, based on the analysis of the Mexican endemic avifauna. We modeled the potential distribution areas with the MaxEnt algorithm for those species that have had or could be susceptible to taxonomic updates based on the PSC.

Results: Of the 93 studied species, 68 were highly restricted, and 23 have high scores according to the evaluation of the Partners In Flight conservation status, so they can be considered species with high vulnerability or risk of extinction. Additionally, based on the recognition of several allopatric populations as independent phylogenetic species, 45% are susceptible to reconsideration of their risk categories due to a decrease in the extent of areas where they are potentially distributed.

Implications for Conservation: The use of a taxonomic perspective focused on the phylogenetic relationship of the different populations would directly impact the definition of risk categories, particularly for those endemic or restricted distribution evolutionary units for which there is usually very little information available and which, undoubtedly, are the ones that most need to be studied and, particularly, protected.