Gulls

species: 
Black-headed Gull
scientific name: 
Chroicocephalus ridibundus
notes: 

Orange ring with a black four alpha-numeric code (starting number "2")

note 1 : several ringers participate(d) on the project : for details and direct contact information for the project leader, please, click on the following link: 

https://app.bto.org/static/files/euring/Black-headed_Gull_UK.pdf

colour-ring type: 
Legring : one, coded.
colour-ring colour (of the c-ring): 
Orange [O]
colour-ring code (of the c-ring): 
Four alpha-numeric code (4 letters/numbers).
First letter/number (of the c-ring): 
2