Eagles are one of the many sacred animals of Zeus and when concerning Zeus, it is one of the most important to me, next to the ram. I feel like you can learn some things about a god when you contemplate the symbolism of a sacred animal. Porphyry explains why the eagle is sacred to Zeus “because he is master of the gods who traverse the air, as the eagle is master of the birds that fly aloft”.
The eagle symbolises strength, far sightedness and authority, these are also a few of the qualities Zeus is described to have. He is described as the strongest of gods (Zeus Sthenios), a god who orders (Zeus Kosmetes) and a god who protects (Zeus Apemios).
In mythology, Zeus transformed into an eagle, or sent one, to abduct the young Trojan prince, Ganymedes. Afterwards, Ganymedes became the cupbearer of the gods and a lover of Zeus. The myth itself reflects the norm of pederasty in Ancient Greek society and indeed, Ganymedes is associated with homosexual love in some way.
The myth of Zeus and Ganymedes also represents something else to me. I also see it as somewhat of an allegory of the devotional relationship between man and the divine. When we pour a libation, we are essentially acting as a ‘cupbearer’. While it’s highly unlikely we will become immortal, we become ‘elevated’, in a way, when glorifying the gods.
Of course, this is just one perspective I have on the myth and a personal one at that.