Molecular systematic and biogeography of the Synallaxis rutilans species complex (Aves: Passeriformes: Furnariidae)

The Amazon has some of the highest levels of bird diversity of the world; however, phylogeographic studies show that this diversity is underestimated. The Synallaxis rutilans Temminck, 1823, species complex deserves attention for presenting a restricted distribution in the Amazon basin, and does not have a satisfying taxonomic resolution. The most recent taxonomic review for this species complex used morphological characters and recognized three taxons: rutilans, amazonica and omissa, and proposed the validation of S. omissa as a species, because of plumage differences and restrict geographic distribution to the Belém endemism area. For a better understanding of the evolution process in this complex we did phylogeographic and population analysis, sequencing two mitochondrial markers for 86 individuals, consisting of all taxons in this complex. The phylogenetic analysis recovered a well-supported topology by Bayesian inference with seven evolutionary lineages, whose distribution is delimited by the Amazon river’s main tributaries. The diversification of these lineages started at about 1.5 Ma at the Pleistocene. The population structure analysis recovered six populations. The populations of Belem and Xingu endemism area were grouped in the same population. The haplotype network showed that the lineages of the north Amazon river do not share haplotypes with the lineages of the south, the lineages of the opposite sides of the Negro River also do not share haplotypes. The historical demographic reconstruction of this complex showed that there was no population expansion or retraction over time. The molecular results corroborate the underestimated diversity of this group according to the current taxonomy.