Recognizing chorotypes for terrestrial Mexican mammals: contrasting datasets and units of analysis, and ecological implications

Abstract

Chorotypes are groups of species that share a similar distribution within a study area. Their identification depends on the geographic units and the taxa analyzed. For the terrestrial Mexican mammals, identification of chorotypes has not been explored yet. Our objectives are (1) to identify chorotypes for the species of terrestrial Mexican mammals using two different datasets (Map of Life [MOL] and International Union for Conservation of Nature [IUCN]), (2) to compare the results using biogeographic provinces, and (3) to discuss the relevance of the chorotypes for ecological regionalization. More than 400 species of mammals were used to identify 33 chorotypes in four different analyses: MOL and IUCN with the whole Chihuahuan province, and MOL and IUCN splitting it into Northern and Southern Chihuahuan. For the 33 chorotypes, one was recovered in all analyses, one was shared by three analyses, seven were shared by two, and 24 were unique for one. We demonstrate the importance of the use of different datasets of geographic distribution of mammals, as well as pre-defined units of analyses, and their influence on the results of a chorotype analysis. Most of the chorotypes identified the mixture of Nearctic and Neotropical biotas in the Mexican territory, but more interestingly, the affinity of ecological patterns of lowland and highland areas.