Molecular phylogenetics and biogeography of tanagers in the genus Ramphocelus (Aves).

Ramphocelus tanagers are distributed throughout the Neotropical lowlands. In this paper, mitochondrial DNA (mtDNA) sequence data from cytochrome b and ND2 genes are used to estimate relationships among seven of nine species of the avian genus Ramphocelus. Genetic differentiation is high between Ramphocelus passerinii passerinii and Ramphocelus passerinii costaricensis, and the two subspecies are diagnosable and distinct from one another both morphologically and genetically. Thus, elevation to species status is recommended. Three clades are supported by both gene sequences; one clade contains R. passerinii, R. costaricensis, and R. icteronotus; the second clade contains Ramphocelus carbo, Ramphocelus bresilius, and Ramphocelus nigrogularis; the third clade contains Ramphocelus sanguinolentus. The degree of saturation was assessed for both genes and saturation of third position of codons occurs by 10-12% uncorrected pairwise sequence divergence. The general area cladogram suggests the following area relationships: Pacific and Caribbean Central America are sister areas, Chocó is the sister to the Central American area, and Amazonia/southeastern Brazil is the outgroup area to the Chocó/Central American clade.