In recent years I’ve seen reports of some unusual trans-species friendships. There are Tarra and Bella, an elephant and a dog who became best friends. Several years ago, there were Owen and Mzee, a young hippo and an old tortoise. A search of the internet turns up a variety of less well-publicized odd animal pairings (the hamster and snake have to be the most surprising, as Gohan was initially intended as a meal for Aochan, not as a companion).
But a deer standing guard over a goose’s nest differs from the above, as the relationship is not one of two companions but of protector and protected. How does the buck even know that the goose needs protection? A male deer will fight other stags to protect his herd of female deer. Does this one know that the goose is female?
I wonder if anyone has ever encountered a real-life friendship between a meerkat and a warthog.