Size of a Eurasian Jay, with a long and heavy bill, spotted body, and black cap. During its undulating, woodpecker-like flight, the short tail with white vent and white tail tips noticeable. Breeds almost invariably in spruce forests. Feeds on nuts, especially hazel and arolla pine, storing large amount of nuts for winter. During summer also feeds on invertebrates. Mostly resident but large numbers may irrupt periodically out of the normal range when pine seed crops fail.