The Eurasian Jay (Garrulus glandarius) has 8 racial groups (33 subspecies in total) whose characteristics vary from a streaked crown or a black crown, a white face, a reddish face, either a white forehead or not, either a white wingpatch or not, etc.
This is the eastern Europe/Middle-East race of the Eurasian Jay (the atricapillus group) which is different to the western European variety in that it has a thicker bill, a white forehead and a black crown (not streaked).
The western Balkan area, including Greece, has the subspecies Garrulus glandarius graecus while Samos has its own subspecies: Garrulus glandarius samios (3rd, 4th & 5th photo).

1st & 2nd photo: Garrulus glandarius graecus, Lesvos, Greece, 1 May 2010
3rd, 4th & 5th photo: Garrulus glandarius samios, Kokkari, Samos, Greece, 1 May 2025