Black-throated Flowerpiercer (Diglossa brunneiventris) - HBW 16, p. 274

Taxonomy: Diglossa brunneiventris Lafresnaye, 1846, Peru.
Genus has sometimes been placed in Coerebidae or Parulidae or even, because of an apparent close relationship to Acanthidops, in Emberizidae. Molecular phylogenies indicate that it is most closely related to Xenodacnis and to Acanthidops, Haplospiza and Catamenia (the last three genera currently placed in Emberizidae), and that all clearly belong in present family. Members of this clade may also be closely related to the Oreomanes–Conirostrum clade. Present species forms a monophyletic group with D. gloriosa, D. humeralis and D. carbonaria, and all were previously regarded as conspecific; known to hybridize, to limited extent, with D. carbonaria in small area of range overlap in Bolivia (La Paz). Isolated N race vuilleumieri, two populations of which are separated by c. 1500 km from larger nominate race in S, occurs in very humid zones, whereas nominate mainly in dry to arid zones, and song of at least W population of vuilleumieri (on Páramo Frontino) differs markedly from that of nominate (though specimens of the two are so similar that many, if not most, are racially inseparable); further taxonomic investigation required. Two subspecies recognized.