Molecular phylogeny and systematics of Neotropical toucanets in the genus Aulacorhynchus (Aves, Ramphastidae)

We studied the phylogenetic relationships in the genus Aulacorhynchus, an assemblage of Neotropical toucanets distributed from Mexico south to Bolivia. Based on mitochondrial and nuclear DNA characters, we obtained a robust hypothesis of relationships for all recognized species, including good representation of distinct geographic populations. Our results support the monophyly of the genus Aulacorhynchus, but contradict previous taxonomic arrangements. The genus is made up of three major clades: the Aulacorhynchus prasinus complex, Aulacorhynchus huallagae+Aulacorhynchus coeruleicinctis, and Aulacorhynchus haematopygus+Aulacorhynchus sulcatus+Aulacorhynchus derbianus. Andean populations of A.derbianus are more closely related to A.sulcatus than to Pantepuian populations of A.derbianus, rendering A.derbianus paraphyletic. Based on the molecular phylogeny, and information on geographic distributions and morphological and behavioural characters, we review the specific status of these taxa and propose a new taxonomic arrangement within Aulacorhynchus.