Reevaluation of the taxonomic positions of members of the Epinecrophylla fjeldsaai (Aves: Passeriformes: Thamnophilidae) antwren complex including E. fjeldsaai based on vocalizations

The northwestern populations in the dead-leaf-foraging Epinecrophylla haematonota complex of thamnophilid antwrens includes E. pyrrhonota, E. fjeldsaai, and E. haematonota. Their taxonomic position has been the subject of recent debate. Divergence in homologous vocalizations provides a principal measure of reproductive isolation and species status for thamnophilid antbirds under the biological species concept, but until recently their evaluation as species has been hampered by the paucity of recordings of E. fjeldsaai. That insufficiency has been remedied, enabling an analytic comparison of vocalizations of the 3 taxa. The results of this analysis led to the recommendation that the 3 taxa be ranked as subspecies of Epinecrophylla haematonota.