Yellow-Billed Oxpecker

The Red-Billed Oxpecker (Buphagus africanus) is a passerine bird in the oxpecker family.
It is native to the savannah of Africa, from Senegal to Sudan. Its range overlaps that of the Red-Billed Oxpecker. 
Behavior
The yellow-billed oxpecker nests in tree holes. It lays 2–3 eggs. Outside the breeding season it forms large, chattering flocks. Non-breeding birds will roost on their host animals at night.
The yellow-billed oxpecker eats insects and ticks. It perches on large wild and domesticated mammals such as cattle.
The yellow-billed oxpecker has plain brown upperparts and head, buff underparts and a pale rump. The feet are strong. The adults' bills are yellow at the base and red at the tip, while juveniles have brown bills. Its flight is strong and direct. The call is a hissy, crackling krisss, krisss.