Systematics

Chlorospingus tacarcunae is considered to be monotypic (Wetmore et al. 1984, Hilty 2011). Although plumage or morphometric variation has not been detected, potential genetic variation should be the focus of future research given its patchy distribution across several mountain ranges in central Panamá, and the Serranías de San Blas and Darién.

Described as Chlorospingus tacarcunae Griscom 1924; type locality Mt. Tacarcuna, east slope, 4600 feet [1499 m], eastern Panama

Tacarcuna Chlorospingus was considered to be a subspecies of Yellow-throated Chlorospingus (C. flavigularis) (Hellmayr 1936), but both are sympatric in central Panamá and Cerro Tacarcuna, with no evidence of hybridization (Blake 1989, Weir et al. 2008, Renjifo et al. unpublished data). Alternatively, Zimmer (1947) treated tacarcunae as a subspecies of Common Chlorospingus (C. flavopectus), a classification that was followed by Meyer de Schauensee (1966, 1970). Sibley and Monroe (1990) considered C. tacarcunae to form a superspecies with C. flavopectus and Pirre Chlorospingus (C. inornatus). However, most classifications have followed AOU (1983) and Wetmore et al. (1984) in treating it as a separate species (Remsen et al. 2015). Molecular phylogenetics have recovered the genus Chlorospingus as monophyletic, with the exception of Yellow-green Chlorospingus (C. flavovirens), which is a member of Thraupidae (Klicka et al. 2014, Avendaño et al. 2016). Within Chlorospingus, C. tacarcunae was found to be nested in a clade containing South American subspecies of C. flavopectus, as well as C. inornatus and Dusky Chlorospingus (C. semifuscus), but sister relationships within this clade were not well supported (Weir et al. 2008). Klicka et al. (2014) corroborated these results, but found good support for C. tacarcunae as sister of the clade composed of C. inornatus and C. semifuscus. The geographic and phylogenetic position of C. tacarcunae suggest a South American origin possibly as a result of a single colonization event to the Darién during the last 3.3-3.0 Ma (Weir et al. 2008).