Heuglin's White-eye

With its features, yellow plumage and white-ringed eye, Heuglin's White-eye is instantly recognizable to the genus Zosterops. There is no sexual dimorphism in Heuglin's white-eye and the immature looks like the adult. The nominate subspecies of adult Heuglin's White-eye have a bright yellow forehead, chin and throat. The rest of the head, upperparts, wing coverts and rump fringes are olive-green, tinged with yellow. The brown eyes are surrounded by a white ocular ring, 1 to 2 mm wide. The black lores extend as a half-moon below the eyes. The thin and pointed beak is black, slightly bluish at the base. The underparts vary according to subspecies. The upperparts and sides of the chest are light grey. The flanks have a grey tinge of tawny. The belly is white, sometimes tinged with yellow. The undertail coverts are yellow. The legs are slate-grey.
The subspecies differ in the colour of the upper parts, from yellow-green to more intense green, and in the colour of the lower parts. In kaffensis subspecies, the middle of the body is yellow from the chest to the undertail coverts, while the sides of the chest and flanks are dark green. In kulalensis, there is a strong contrast between dark grey flanks and sides and a pale mid-ventral band, tinged with yellow. The perception of colours of the upper parts is often distorted by ambient light, making this criterion less useful.