Alkonost

Sources present Alkonost as an individual legendary bird-woman within East Slavic lore rather than a generic species. Folkloric accounts place her in the underworld with the Sirin; this pairing and the narratives about her actions link her to seasonal and cosmological functions in Slavic folk worldview. The name Alkonost is reported by the available sources to derive from the Greek name Alcyone, a classical figure transformed into a kingfisher, suggesting cross-cultural influence on the bird's name and certain conceptual parallels (Wikipedia).

In the supplied materials Alkonost is consistently described as a woman-headed bird: an avian body bearing a female human head. The sources provide no standardized details of size, exact plumage color, or the precise species of bird she resembles; descriptions in summaries and encyclopedia entries maintain the core motif of the human-headed bird-form as the defining visual feature (Wikipedia).

Folklore sources attribute several distinct powers and behaviors to the Alkonost. Her song is famed as extraordinarily beautiful and enchantingly dangerous: those who hear it 'forget everything they know and want nothing more ever again,' a motif repeated across sources (Wikipedia; supplemental blog summary). Narratives tie her reproductive behavior to weather phenomena: she lays eggs on a beach and rolls them into the sea, and when those eggs hatch a thunderstorm arises and the sea becomes impassably rough (Wikipedia). In a calendrical/ritual context, tales say that on the Apple Feast of the Saviour day Sirin cries in the morning while the Alkonost appears in the afternoon to rejoice; by brushing dew from her wings she grants healing powers to the fruits on the tree where she alights, connecting her action to blessing and fertility of harvest (Wikipedia). She is also named as a sister-figure to other Slavic mythic birds such as Rarog and Stratim (Wikipedia).