Fairy-bluebirds are small, vibrant, fruit-eating birds found in tropical southern Asia and the Philippines, belonging to the genus Irena and the monotypic family Irenidae, closely related to ioras and leafbirds. They flaunt sexually dimorphic colors, with males sporting dark blue plumage and females in a duller green. They primarily feed on fruits like figs, and may consume some insects, laying two to three eggs in tree nests. Their calls are distinct, and species are regionally distributed, with the Asian fairy-bluebird, Philippine fairy-bluebird, and Palawan fairy-bluebird inhabiting different locations. Initially, scientists debated their classification, but molecular studies confirmed their close relationship with leafbirds. In terms of morphology, fairy-bluebirds have robust bodies, with sexual and geographic variations in size, and exhibit plumage that's exceptionally vivid in sunlight but more camouflaged in shade. They inhabit fruit-producing forests, from evergreen to semi-evergreen, typically in the canopy. Observations show that they forage in pairs or small groups for fruit and nectar, rarely alone, and that their diet shifts to insects for nestlings. During courtship, males display intricate vocalizations leading to cooperative nest building and rearing of chicks in trees or tall bushes by both sexes.