Symbolism of the raven:
"The Raven is the Native American bearer of magic, and a harbinger of messages from the cosmos. Messages that are beyond space and time are nestled in the midnight wings of the Raven and come to only those within the tribe who are worthy of the knowledge.
The Raven is also called upon in Native ritual for healing purposes. Specifically, the Raven is thought to provide long-distance healing.
The Raven is also a keeper of secrets, and can assist us in determining answers to our own “hidden” thoughts. Areas in our lives that we are unwilling to face, or secrets we keep that harm us – the Raven can help us expose the truth behind these (often distorted) secrets and wing us back to health and harmony."
http://www.symbolic-meanings.com/2007/11/15/symbolic-meaning-of-the-raven-in-native-american-indian-lore/