A tiny-bodied sunbird in which breeding males are colorful and distinctive, and females and non-breeding males quite drab. Breeding males have a green back, a yellow belly, and extremely elongated central tail feathers. Females and non-breeding males have gray-brown upperparts and pale-yellow underparts. Similar to Nile Valley Sunbird, but there is very little overlap in range; males are distinguished by their lack of purple on the back and breast, and females by being darker overall and having a less distinct pale eyebrow. Also similar to female Beautiful Sunbird, but yellower below, with a shorter bill. The most common call is a rising “sweet,” and the song is a typical sunbird jumble.