Described on Ebird as "A small bird of forest and edge from the lowlands to low elevations in the mountains on Luzon and Catanduanes. Has a fairly long, curved bill, olive upperparts, and a yellowish upper belly. Male has a blackish tail, face, throat, and chest, with green iridescence on the forecrown and purple on the throat. Similar to Olive-backed Sunbird, but has a red chest spot, an orange wash on the upper belly, and no white outer tail feathers. Female has a gray throat and lacks the yellow brow. Voice includes a high-pitched double-noted call, “chik-chik!”[2]
It was previously conspecific with the Maroon-naped sunbird but it differs in molecular genetics, a less glossy crown, the a greenih instead of maroon nape and duller yellow belly.
Subspecies
This species is now monotypic but two subspecies were formerly recognized:
A. f. flagrans – Found on Northeast Luzon
A. f. decolor – Found South Luzon and Catanduanes;
Subspecies weakly differentiated and have been synonymized.[3]
Ecology and behavior
Not much is directly known about its diet but often seen feeding on nectar of the non-native Hibiscus and pressumed to feed on insects and even seeds. Typically seen alone or in pairs but also joins mixed-species flocks [3]
