Yellow-billed oxpeckers
Two yellow-billed oxpeckers (Buphagus africanus africanus) perched atop a zebra in Senegal. This bird is native to the savannah of Sub-Saharan Africa, where it feeds on insects and ticks, including the arthropod parasites found on large mammals, as well as blood. The species nests in tree holes lined with hair plucked from livestock, where it lays 2–3 eggs.Photograph: Charles J. Sharp