Nucifraga caryocatactes
Largely unmistakable. Chocolate brown body with small white dots. Wings and crown dark brown without spots. Tail dark with broad white edges/corners. Vent shiny white. Recognizable at long distance when in flight, by its peculiar flight pattern and profile. Fluttering, "inefficient" wing beats, short tail, long bill and often a throat bulging with seeds.
Fairly silent. Warning call a characteristic dry and rasping "karrr karrr karr" in even pitch. Song a quiet improvisation of whistling and clappering sounds, interspersed with mimicry of other birds.
Xeno-canto: map
Birdlife ecology