Red-billed oxpeckers squabble over prime seating on the back of an African buffalo. These birds are famous for travelling on tolerant buffalo and other mammals, feeding on various insects on their hosts or nearby.
When the time comes, these birds build nests in tree cavities, which makes this photo all the more interesting. This group of birds seem to be using a rudimentary nest made out of mud and hair plucked from the back of this buffalo. This is the first time I have seen this and I haven’t been able to find any reports elsewhere, so if anyone has some insights into this behaviour, please share!
Owen Slater Photography 
Very cool, it looks as though that is where they are going to nest. Nice and cosy for the chicks if that is where they are hatched. Wouldnt you just love to follow that buffalo for a few weeks to see what would happen?
It did look like they were going to try, but I doubt the nest would have lasted very long. One roll by the buffalo or a heavy rain and that would have been the end of that!
Wonderful photo.