The beautiful band of the Milky Way is now passing nearly directly overhead in the hour before midnight each night (it can be seen earlier than that as well, but it will be further to the east, still rising towards the center of the sky).  It is a spectacular sight and well worth walking out to see during the dark midnight hour, especially now when the moon is still very young and following close behind the setting sun, leaving the rest of the night very dark and very conducive to stargazing.

Two of the most distinctive constellations in the band of the Milky Way are the important celestial birds of Aquila the Eagle and Cygnus the Swan.  They are very easy to locate, especially since each contains one of the bright stars that make up the Summer Triangle (Altair in the Eagle and Deneb in the Swan).  

The diagram above shows the Swan and the Eagle in the Milky Way: the Swan is depicted at the top of the image and is "flying" towards the bottom (which is also towards the southern horizon, for northern hemisphere viewers), and the Eagle is depicted at the bottom of the image and is "flying" towards the top of the image.  This previous post (from which the above image is taken) discusses the importance of these two constellations in greater detail, and shows the Summer Triangle as well.

These constellations feature prominently in shamanic tradition and practice in the parts of the world in which shamanism survived into the nineteenth and twentieth centuries.  One of the most distinctive capabilities of the shaman is his or her ability to fly, possibly indicating the ability to deliberately undertake an out-of-body experience, often by transformation into a bird such as an eagle.  The fringed garments worn by shamans around the world (an example from North America is shown in this previous post) very likely indicates this ability to transform into a bird, and the celestial aspects of the shaman's journey are very evident in the traditions that have been recorded around the world, and are discussed by the authors of Hamlet's Mill.

It is my belief that it is the spirits of the constellations of the Eagle and the Swan which bring back the Goldi (or Nanai) shaman from his journey into the other world, as described in various accounts by those who witnessed their ceremonies.  In his landmark work Shamanism: Archaic Techniques of Ecstasy (1964), Mircea Eliade describes the nimgan ceremony of the Nanai of north-east Asia, during which the shaman guides the departed soul of a deceased person to the other world:
At sunset preparations for the departure are made.  The shaman sings, dances and daubs his face with soot.  He invokes his helping spirits and begs them to guide him and the dead man to the beyond.  He leaves the yurt for a few minutes and climbs a notched tree that has been set up in readiness; from here he sees the road to the underworld.  (He has, in fact, climbed the World Tree and is at the summit of the world.)  At the same time he sees many other things: plentiful snow, successful hunting and fishing, and so on.
Returning to the yurt, he summons two powerful tutelary spirits to help him: butchu, a kind of one-legged monster with a  human face and feathers, and koori, a long-necked bird.  Without the help of these two spirits, the shaman could not come back from the underworld; he makes the most difficult part of the return journey sitting on the koori's back.  211.
Here is another mention of these two important spirits, from Shamanism in Eurasia by Vilmos Diśzegi and Mihály Hoppál.  On page 209 of volume 4, again recording the shamanic practices of the Goldi or Nanai, we read:
on your chest and on your back, you will hang the toli  that will protect your body from the arrows of the shamans’ enemies.
Then you will make a belt out of rattles : ... and
the drum will take you to the buni any time you want; you will be helped by the spirit Butchu and by the bird Koori, who will always bring you back from the buni.
To support the theory that the spirit Butchu and the bird Koori are connected to the Eagle and the Swan, we can first note that the Milky Way was seen as the road that the departed spirits traveled after leaving this world, as well as the road down which spirits traveled before entering a new baby being born.  The evidence for this assertion is discussed at length in Hamlet's Mill.  Some of this evidence is discussed in this previous post.  This fact reveals the significance of the description from Mircea Eliade, in which the shaman "sees the road to the underworld."  

If this road is the Milky Way, then that fact sheds light on the tradition in which two beings associated with the stars we know as the Eagle and the Swan are the beings essential to bringing the shaman back to this world.

As for the identification of Butchu and Koori with the Eagle and the Swan, look again at the description recorded by Mircea Eliade.  The spirit Butchu is described as being "one-legged" -- look again at the diagram of the constellations at the top of this post, and you will see that this description is quite apt for the arrangement of stars in Aquila the Eagle.  

The bird Koori is described as "a long-necked bird" -- and again, if you look at the diagram of the stars in the constellation Cygnus the Swan you will see that it indeed does have a very long neck.

One other detail, this time recorded in the passage above cited from Shamanism in Eurasia, provides a further clue that this identification for Butchu and Koori is on the mark, and that is the mention of arrows ("the arrow's of the shamans' enemies").  Right between the constellations of the Eagle and the Swan is the small but distinctive constellation known as Sagitta, the Arrow.  It is diagrammed and discussed in this previous post.  Its shape is such that it can hardly be viewed as anything but an arrow when you find it in the sky.  The mention of the arrows in conjunction with the safe passage given by the spirit Butchu and the bird Koori may be further evidence that these aspects of the shamanic ritual indicate the travel of the shaman guiding the departed soul is a journey to the macrocosm of the celestial realm, and that the portion of the Milky Way containing the Eagle, the Arrow, and the Swan is being indicated by that part of the ceremony.

The image below, from Wikimedia commons, of the ceremonial dress of a Nanai shaman is significant to the themes discussed above.  Note that it has tassels on its fringes, very similar to the example from North America linked above.  It also depicts, in its lower half, the World Tree mentioned by Eliade.  And, at the base of that World Tree, we see a distinctive image of a Swan drawn on the clothes.

I believe the connection between the shamanic journey and the celestial realm is very important, especially in light of the connection between the shamanic journey and the ancient Egyptian Pyramid Texts alleged by Dr. Jeremy Naydler.  The possibility that the Butchu and the Koori are associated with the constellations of the Eagle and the Swan in the Milky Way should be explored further.