My friend Dimiter Georgiev, from Bulgaria, is sending this set of photos at Varna Lake.
This gull shows features both from michahellis and cachinnans, so I cannot rule out a hybrid.
Important features supporting michahellis:
* Pale iris
* P10 pattern
And those supporting cachinnans:
* Half rear neck collar
* Long legs
* Jizz on the first photo
Bill is somewhat confusing, showing no hints towards micha or cachi IMO.
Opinions would be appreciated.