Gulls

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

Yellow ring with a black four alpha-numeric code (first letter H and three alpha-numerics). 

note 1 : project starts during 2019.

note 2 :  

email sighting submit: 
colour-ring type: 
Legring : one, coded.
colour-ring colour (of the c-ring): 
Yellow [Y]
colour-ring code (of the c-ring): 
Four alpha-numeric code (4 letters/numbers).
countries where ringed: 
Hungary.
First letter/number (of the c-ring): 
H