Frosty-pale bundle of joy. Nominate northern population is white with a shadowy black outlining of the cheek, bright blue-and-white striped wings, and a clean white breast. Central Asian and Central Chinese birds have a bright yellow patch on the breast. Prefers open forested or shrubby areas, often in proximity to willow, birch, and various conifers. More common in open habitats in northern range. Forages actively, often within dense foliage, and can be surprisingly difficult to see well. Gives various high-pitched calls, including chips, trills, and rattles. Song is variable, and includes high whistles followed by a rattling stutter, as well as a series of cheery repetitive two-note calls.