Gray-headed Greenbul

Large, mostly white stork with black flight-feathers and conical red bill. Breeds in open farmland and wetlands, with bulky stick nests conspicuous in trees and often on buildings. In nonbreeding season forages in open areas such as grasslands and agricultural areas. Flies with neck and legs outstretched, and strong, deep wingbeats interspersed with glides. Also soars on thermals; flocks migrate during daytime, often high overhead.

Strange, long-tailed tanager-like bird with thick bill. Once thought to be a warbler, but now considered unique in its own family. Bright yellow throat and breast, contrasting white spectacles, and dull olive-green upperparts. Known for its skulking habits. Often difficult to see in dense thickets, shrubby areas, and field edges. In breeding season, however, males can sit on conspicuous perches to sing and even perform a flight display. Fairly widespread but typically uncommon across much of the U.S. and Mexico, wintering to Costa Rica. Song is variable series of slow whistles, hoots, and chatters. Feeds mainly on insects; also fruit in winter.

Males appear overall gray, with a darker back and cap and a paler belly and throat. Females are similar but with reddish tones to the head. All individuals have extremely short tails with bright white outer tail feathers. An easily overlooked, diminutive warbler of montane forests, where it is often found in shaded thickets. Calls include a typewriter-like trill and nasal “nya nya nya” calls. Birds will sometimes duet, with the female giving nasal calls and the male giving clear, often paired whistles. Birds on Bioko also give a whistled “wheet” that rises in pitch.