Falklands

[Louis VI the Fat]

As regards the special relationship:

A rhinoceros and an oxpecker bird have a special relationship. The Rhinoceros gets its ears cleaned, is kept free of parasites, the oxpecker helps the rhino by removing the ticks who terrorize it.
The bird gets guaranteed safety in return. Nobody challenges a rhino to get a bird. The bird is guaranteed of his supply of food in this manner too, enjoys all sorts of perks.

This relationship is intimate, mutualistic, and both animals rely on it for their very health and ultimate safety.

It does not imply a relationship of recipocitry, nor of equality. The bird does not expect the rhino to follow it, never. The rhino decides, always. The bird travels along on its back, and enjoys the perks of its free ride.