McKay’s Bunting is an irregular species and a very sporadic breeder in the Pribilofs. The identification pitfalls are legion, as the species hybridizes extensively with the Pribilof’s local Snow Buntings. The general theory is that during the fall exodus, when McKay’s Buntings leave their breeding grounds of Saint Mattew and Hall Islands (Roughly 300 miles north of the Pribilofs) a few individuals wander south to the Pribilofs instead of east to their main wintering grounds of the Y-K Delta. These wayward individuals remain on the island through the winter, joining the roving flocks of Snow Buntings that are reported by the locals. When spring comes to the island these birds sometimes stay, setting up territories and pairing with (usually) Snow Buntings. These breeders can return for a few successive years. The progeny of these birds are hybrids, and appear to be fully fertile. Close inspection of Plectrophenax Buntings on the island will reveal that a large number of the “Snow’s” appear to have some “McKay’s” Bunting genes. Finding a pure McKay’s is further complicated because the full range of variation within McKay’s Bunting is not known. It is likely that there are birds breeding on Saint Matthew and Hall Islands that do not resemble “classic” McKay’s as shown in fieldguides. Potential McKay’s Buntings should show pure white backs, white alulas, and black on the tips of only the central tail feathers. Black on the tertials, and even some black on the scapulars is probably also ok. Look for this species in amongst the rocky volcanic flows or isolated peaks of the island’s western half.