Environmental niche drives genetic and morphometric structure in a widespread bat

Abstract

AbstractAimTo explore whether environmental factors are correlated with genetic and morphometric differences in the widely distributed bat speciesTadarida brasiliensis.LocationNorth America and Central America.MethodsWe used an extensive sampling comprising 131 localities that represent heterogeneous environments across the Nearctic and Neotropical regions. Museum specimens were examined and 25 craniodental characters were recorded. Individuals were genotyped at one mitochondrial locus (mtDNA) and nine nuclear loci (nDNA). Clustering and phylogenetic analyses were used to identify differentiated groups. Environmental variables andPCA‐env approaches were used to determine the climatic niche and to measure the niche overlap, equivalence and similarity between groups. Mantel tests between genetic groupings and environmental variables, dispersal costs, Euclidean geographical distances and niche overlap were performed.ResultsWe identified six genetic groups within Central and North AmericanT. brasiliensisbased onnDNA. The most strongly differentiated group, in bothnDNAand mtDNA, was located in central Mexico. Morphometric data showed that individuals from populations in Florida are slightly larger than the others. Niche overlap was detected among Neotropical groups but not among Nearctic groups. The currently recognized subspecies were not recovered as distinct groups with either genetic or morphometric data.Main conclusionsOur approaches suggest that environmental niche variation may help shape the distribution of genetic variation across heterogeneous landscapes, particularly in widely distributed species. Environmental niche analyses suggest that genetic differences between migratory and non‐migratory groups ofT. brasiliensismay be promoted by climatic variation throughout the Nearctic and Neotropical regions. In addition, genetic and morphometric analyses do not support the current subspecies classification ofT. brasiliensisin North and Central America, which should be abandoned.