Altitudinal distribution of birds in a priority area in Sinaloa-Durango, Mexico

We document patterns of species richness and endemism in an elevational gradient (300 to 2 800 m) located in the Espinazo del Diablo region (states of Durango and Sinaloa), as well as its significance for the conservation of the avifauna, that is a global priority due to the presence of endemic and highly endangered taxa. We recorded a total of 209 species of birds in the fieldwork, and adding the records from literature and collections, the list increases to 229 bird species in the area. The 3 methods used for recognizing faunistic assemblages along the elevational gradient phenetic similarity analysis, faunal congruence curves, and TWINSPAN- recognized 3 altitudinal associations, 1 in the lowlands and 2 in the higher elevations, what represents a clear division of the avifauna. The area is a conservation priority in Mexico, because is the northernmost relict of cloud forest in Mesoamerica, and holds an extraordinary combination of species richness, endemism, and presence of endangered taxa.