Gulls

species: 
Black-headed Gull
scientific name: 
Chroicocephalus ridibundus
EURING code: 
05820
notes: 

Yellow ring with a black four alpha-numeric code, starting letter 'T'.

note 1 :

Images: 
snailmail sighting submit: 
Polish Ringing Scheme, Stacja Ornitologiczna MiIZ PAN, ul. Nadwislanska 108, 80-680 Gdansk, Poland.
colour-ring type: 
Legring : one, coded.
colour-ring colour: 
Yellow [Y]
colour-ring code: 
Four alpha-numeric code (4 letters/numbers).
countries where ringed: 
Poland.
First letter/number: 
T