Terns

species: 
Common Tern
scientific name: 
Sterna hirundo
notes: 

Blue ring with a white three alpha code, starting letter "Y".

note 1 : used codes are YAA-YZZ.

note 2 : 

website sighting submit: 
Ornithological Station, Museum and Institute of Zoology of the Polish Academy of Sciences,
email sighting submit: 
colour-ring type: 
Legring : one, coded.
colour-ring colour (of the c-ring): 
Dark Blue [B]
colour-ring code (of the c-ring): 
Three alpha code (3 letters).
countries where ringed: 
Poland.
First letter/number (of the c-ring): 
Y