Gerda Steiner & Jorge Ledzlinger, Joutsenlampi (Swan Lake) 2006
"In pre-Christian times, death was perceived as a deep, healthy sleep. Hence, death did not really exist, just sleep and the waking up into a new life. Therefore one had to be on guard when going to sleep; because there was only a subtle difference between the sleep of life and the sleep of death, one had to take care to wake up in the morning. The protector of the sleep of life was a bird, and the sleeper was protected by a wooden carving of a bird next to the bed.
In many cultures, the transition from life to death is symbolised by a river. There are no upper or lower worlds like heaven and hell. Crossing the river erases all memories. It is not possible to write in water. A guard on the river ensures that no living people trespass into the realm of death. In Finland, the swan Laulujoutsen was the guardian of the other world, Tuonela. The Finnish swan – once almost extinct – has returned as the mythical national bird, struggling to defend its habitat against the invasion of its slightly larger, orange-beaked cousins from Central Europe." (http://www.steinerlenzlinger.ch/eye_joutsenlampi.html)