Бюльбюль цитриновий Microtarsus nieuwenhuisii

Very rare and little-known species known from two sites in Borneo and one in Sumatra. Olive-yellow with a dark head and namesake blue eye-rings. Somewhat resembles a duller Black-headed Bulbul; potentially of hybrid origin. Ecology, behavior, and vocalizations essentially unknown, though has been known to associate with Black-headed Bulbuls at fruiting trees.