Astral projection was the original ability of the Quileute tribe, before the time of shape-shifters.
The Quileute tribe settled in La Push and became efficient fishermen and shipbuilders. As time passed, other people coveted their land and moved against them for it. The tribe was small and could not defend themselves, so they took their ships and left the land. At sea, Kaheleha used the magic in their blood to defend it. He was the first Spirit Chief in Quileute history. He and all of the men left the ships in spirit only, leaving their bodies behind under the care of the women. Though they could not physically hurt the enemy, the warriors had other ways. They blew fierce winds into enemy camps; they could make great screaming in the wind and could manipulate animals to do their bidding. Animals were the only ones that could see them and help. The invading tribe had packs of thick-furred dogs to pull their sleds in the north, and which were set against them. Bats were brought out of the cliff caverns. As a result, the dogs and bats won and the survivors of the invaders scattered thinking the harbor cursed. The Quileutes released the dogs, who ran wild, and returned to their bodies victorious.
The astral projection ability of the Quileute tribe allowed them to leave their body in spirit form, and they were referred to as Spirit Warriors. In spirit form, they cannot physically touch things, but are able to manipulate wind and animals. In this form, possession is also possible. When in Spirit form, the minds of the individuals are connected similar to a shape-shifter.
Being in spirit form for too long is taxing on the body, which means making long journies in spirit form is difficult, if not impossible. In the case of Taha Aki, who was deprived of his body, and the case of Utlapa, who took Taha Aki's body, possession is possible. Taha Aki was able to possess a wolf, figuring even a wolf's body was better than none at all.