Systematics

Dacnis albiventris is monotypic (Dickinson and Christidis 2014, Clements et al. 2015). However, there have been descriptions of regional differences in vocalizations (Hilty 2011). Further, Peruvian birds have been described as having a more slender bill (Hellmayr 1935, Zimmer 1942).

White-bellied Dacnis is one of nine species in the genus Dacnis (Dickinson and Christidis 2014, Clements et al. 2015). The relationships within Dacnis have not been resolved. A recent phylogenetic analysis of mitochondrial and nuclear loci recovered White-bellied Dacnis as sister to Black-legged Dacnis (D. nigripes), though this relationship was not statistically significant (Burns et al. 2014). Dacnis is a member of the subfamily Dacninae, which includes a monophyletic and strongly supported Dacnis, a monophyletic and strongly supported Cyanerpes, and the monotypic Tersina. The relationships of these genera within Dacninae to each other is not resolved, with alternative hypotheses not supported (Burns et al. 2003, Burns et al. 2014). The Daninae are very sexually dichromatic with blue males and green females, and are the most dichromatic when plumage is quantified and studied using an avian visual model (Burns and Shultz 2012, Burns et al. 2014). Although their plumage patterns are similar, the shape of the bills between these genera are very different, with Dacnis having a particularly shorter and slender bill (Burns et al. 2003, Burns et al. 2014).

Dacnis albiventris (Sclater, 1852) originally was described as Pipridea albiventris with a type locality of Nouvelle-Grenade, now known as Bogotá, Colombia (Sclater 1852a). Other synonyms include Hemidacnis albiventris (e.g., Sclater 1852b, Cassin 1864; Storer 1970). Historically, White-bellied Dacnis was placed in the monotypic genus Hemidacnis because of the small bill length (Hellmayr 1935, Zimmer 1942), but they previously were included in Dacnis (e.g., Cassin 1864) and formally moved back to Dacnis by Zimmer (1942). The genus Dacnis historically was a member of the "nectar-feeding family" family Coerebidae (e.g., Sclater 1886, Hellmayr 1935). Early researchers noticed that some coerebids shared similar morphological features with tanagers, such as horny palletes, skull morphology, jaw muscles, and plumage similarities (Beecher 1951, Tordoff 1954, Storer 1969). Molecular data has confirmed these early hypotheses, and the Coerebidae has been largely rejected, with Dacnis now placed in the Thraupidae (Storer 1970, Isler and Isler 1987, Burns et al. 2003).