South-western Colombia (western slope of western Andes in upper Anchicayá Valley, in Valle del Cauca; Nariño) and Ecuador (in eastern Esmeraldas; Pichincha).
 
Population
Estimated population is 2,500 - 9,999 (2010) and decreasing.
Status VU
Habitat destruction and degradation through logging, small-scale agriculture and gold mining is the main threat.
For more information see BirdLife International Species Factsheet.
Habits
Usually in pairs or groups of 3-6 individuals, often associated with mixed-species flocks.
Food
Primarily fruit. Also flowers and insects.
Voice
A hoarse, rasping rasping 'chut' and 'chip-chut' or 'chut-chip' notes repeated frequently.
Yellow-green Tanager (Bangsia flavovirens) [XC242382]
by Jerome Fischer from Pichincha: Milpe road, Ecuador (call)
Yellow-green Tanager (Bangsia flavovirens) [XC85092]
by Andrew Spencer from La Union Road, 6.5 km NW of Alto Tambo, Esmeraldas, Ecuador (call, song)
Subspecies
No subspecies.
Recent molecular-genetic studies indicate that this genus and Nesospingus, Spindalis and Phaenicophilus form a monophyletic clade that is sister to several New World warbler (Parulidae) genera (including Dendroica, Basileuterus and Vermivora), and are not closely related to other genera of present family. More recent evidence suggests that Chlorospingus is closest to genus Arremonops in family Emberizidae.
Similar Species
Yellow-throated Bush-Tanager (Chlorospingus flavigularis) (which typically forages in lower forest strata) has greyish underparts contrasting with yellow throat and white irides.
References
See References.