there yellow-billed oxpeckers on a hippo head, one pecking parasites, two with open bill, closeup shot showing ear and eye of hippopotamus

oxpecker yellowbilled southern africa hippopotamus amphibius tanzania hippopotamus birds wildlife zambia zimbabwe hippo conservation africa fauna pachyderm environment ear africanus safari symbiosis protection mammal unspoiled herbivore big wilderness mud nature buphagus wild dangerous parasite pinworm eye massive lazy maggot pick water outdoors