Abyssinian ground hornbill (female)

The two species of ground hornbills, Bucorvus abyssinicus and Bucorvus leadbeateri, differ from other hornbills in having an extra neck vertebra (giving them a total of 15), longer legs, thick upper eyelid lashes, and a larger body size. The longer legs adapt them well to their primarily terrestrial foraging method, while other hornbills are mainly arboreal. Northern ground hornbills are black, large-bodied birds average 4000 g in mass and 100 cm in length. They have high, rounded, grooved casques (a bony elaboration of the upper mandible covered with a thin sheath of keratin) that is abruptly truncated distally, and a long, deep, curved beak, which they use to catch and subdue prey. The primaries are white and are highly visible in flight.