www.gull-research.org

Intriguing bird, reported as Caspian, but that seems highly unlikely given the very dark juvenile feathers and general state of moult. LBBG?
http://waarneming.nl/waarneming/view/61603201

Hi Ruud.

LBBG, that´s my immediate impression! However, with an rather unsusal unmarked underwing and belly. Talking unmarked belly... (viewtopic.php?f=4&t=579)

JanJ