Areal distribution of the motif: the white square with black dot indicates where the sky-maiden appears as migratory birds (swans, geese, ducks, cranes or herons) the black circle with white dot, where she appears as a dove the dark blue full circle, where the sky-maiden is either a non-migratory bird, star or sky nymph. Also in the southernmost regions, differently from the North ones, the sky-maiden stories generally have anthropogonic or ethiological value, explaining the origin of humans, cultures, gods, celestial phenomena.
Thus, all the versions where the sky-maiden is a migratory bird are mostly found in northernmost regions, whereas more to the South, the women of the tale are more commonly non-migratory birds, and may also be stars or celestial nymphs. Myths are adapted with the elements found in the local context of each culture, frequently undergoing subtle changes, while preserving most of the original structure or main prototypical elements.
There are also many parallels involving creatures other than swans. There are parallels around the world, notably the Völundarkviða and Grimms' Fairy Tales KHM 193 " The Drummer". In folktales of this type, the male character spies the maiden, typically by some body of water (usually bathing), then snatches away the feather garment (or some other article of clothing), which prevents her from flying away (or swimming away, or renders her helpless in some other manner), forcing her to become his wife. The key to the transformation is usually a swan skin, or a garment with swan feathers attached. The literal swan maiden character in particular is a mythical creature who shapeshifts from human form to swan form. The sky-maiden may also appear in other stories as doves, non-migratory birds, and also as stars or celestial nymphs. More generally, it is also called the bird-maiden or sky-maiden motif, since not always they are swans: the properly called swan maiden appear in stories of the northernmost regions, in which they are part of a group where the bird-maidens are migratory birds, among other variants, such as the goose, duck, crane and heron. This category is one of the most interconnected and centrally referred to among all the other stories, for instance along with the Dragonslayer motif. It also belongs to the larger motif of the "Magic Wife", pertaining to the index category ATU 400, "The Man on a Quest for His Lost Wife", where the man makes a pact with a supernatural female creature, which later departs. It is one of the most widely distributed motifs in the world, most probably being many millennia old, and the best known supernatural wife figure in narratives. Later, the maiden recovers the robe and flies away, returning to the sky, and the man may seek her again. The " swan maiden" story is a name in folkloristics used to refer to three kinds of stories: those where one of the characters is a bird-maiden, in which she can appear either as a bird or as a woman those in which one of the elements of the narrative is the theft of the feather-robe belonging to a bird-maiden, though it is not the most important theme in the story and finally the most commonly referred to motif, and also the most archaic in origin: those stories in which the main theme, among several mixed motifs, is that of a man who finds the bird-maiden bathing and steals her feathered robe, which leads to him becoming married to the bird-maiden. In the Völundarkviða, Wayland Smith and his brothers marry valkyries who dress in swan skins. Please discuss this issue on the article's talk page. Please consider splitting content into sub-articles, condensing it, or adding subheadings. This article may be too long to read and navigate comfortably.