How do I compare the symbol of the scarlet ibis and Doodle to the real world?

Rare creatures, such as the symbolic scarlet ibis and Doodle, are those that Henry David Thoreau once described as "march[ing] to the beat of a different drummer."
Like the ibis, there is a creative and magical quality to Doodle that Aunt Nicey is first to point out when he is born in a caul. "She said caul babies should be treated with special respect since they might turn out to be saints." Indeed, Aunt Nicey has perceived a unique and creative spirit in Doodle. When the brother takes Doodle to Old Woman Swamp, declaring it the "only beauty I knew," a wide-eyed Doodle begins to cry because he is so emotionally moved by how "pretty, pretty, pretty" the area is. The brother then weaves flowers into necklaces and crowns with Doodle.
Clearly, Doodle has the creative spirit, a spirit that places him among artists, musicians, and the like. They are rare creatures who see things that others do not; they imagine things that others cannot, and they hear "the beat of a different drummer." They are the rare "beautiful birds" whose loss are mourned by many because they bring a refreshing uniqueness to the world. They are the creatures who feed the souls of others. The brother realizes his loss as Doodle dies. He cries, holding him and "sheltering [his] fallen scarlet ibis from the heresy of rain."