A story from When Elephants Weep:
John Teal, a researcher whose work involved raising musk oxen (an endangered species), described that one time, he was sealed within the oxen pen when some dogs ran toward the outside of the pen. Immediately, the musk oxen snorted, stamped, and charged at John. He was afraid for his life but, to his astonishment, the oxen did not attack him. Rather, they formed a defensive circle around him, horns facing out, pointing at the dogs—exactly the same as they do when protecting their calves!