Kulal White-eye Zosterops kulalensis is endemic to Mt Kulal, northern Kenya. It is currently considered a Vulnerable species because of its restricted range. We investigated its habitat and microhabitat use, and flocking and foraging behaviour, with respect to seasonal and diurnal variation. In the dry season, Kulal White-eye was encountered only in montane forest, where it was more abundant in glades than in closed-canopy habitats. Here it fed frequently on fruit, as most fruiting occurred in the drier months. In the wet season population density was also higher in glades than in closed-canopy forest, but birds were mostly insectivorous. Foraging in bush outside the forest was favoured. In the wet season, Kulal White-eye inhabited both the forest and the drier bush at lower altitudes, and avoided habitats with mature trees, preferring young tree formations where vegetation was thicker. Flock size was larger in the dry season, and, in the wet season, larger flocks were encountered in the morning and in late afternoon. Our study suggests that Kulal White-eye is less restricted to mature forest than previously thought. The conservation of the species requires that both the forest and the adjoining bush habitats receive adequate protection. Although some traditional human activities could be compatible with conservation, grazing of domestic animals inside the forest and the removal of large tracts of bush to create new pastures could be detrimental to the species.