Species limits in Antbirds (Aves: Passeriformes: Thamnophilidae): an evaluation of Plumbeous Antvireo (Dysithamnus plumbeus) based on vocalizations
Through most of the 20th Century, Dysithamnus plumbeus was considered to comprise three geographically remote subspecies based on plumage: D. p. plumbeus of the lowlands of southeastern Brazil; D. p. leucostictus of the east slope of the Andes from central Colombia to extreme northern Peru; and D .p tucuyensis endemic to the mountains of northern Venezuela. Some recent authors have elevated these taxa to species status without providing additional evidence. We analyzed vocal differences among these taxa and compared the extent of diagnostic differences to a benchmark for species status under the Biological Species Concept (BSC). Vocalizations of D. plumbeus differed sufficiently from the others for D. plumbeus to be considered specifically distinct. Although both calls and loudsongs of the two remaining taxa differed from each other in some aspects, the differences did not meet our benchmark for species separation. We therefore recommend that they be designated as D. leucostictus leucostictus and D. leucostictus tucuyensis pending the acquisition of additional vocal recordings or other contrary evidence.