Red-billed Oxpeckers, + Yellow-billed

Look on the backs of the nearest left side bullocks, 3 red-billed Oxpeckers are visible. The second picture shows a close-up.
I was looking for a better picture and when I found one I resized a section of it and saw there was also a Yellow-billed Oxpecker, see third picture, the bird with the pale bill, dark throat and pale belly. The fourth pic is a close-up of this!