Gulls

Blue ring with a white 4 alpha code and metal ring.

note 1 : The rings are dark blue with white letters. The codes contain a dot in between the letters. The position of the dot is changing troughout the series.
The M-series have no dot !

note 2 : Used codes are : AAAA up to ZZAZ, and AAOA up to ZZOZ, AAEA up to ZZEZ, always with the letter “A” or “O” or “E” at the third position. For example: F.YAK, KAO.G, AL.OF or CS.EB

note 3 : The letter E, I, J, O, Q, V, W, and X have not been used as FIRST letter.

note 4 : In most cases the ring must be read upwards. Typically, the blue rings were placed at the right tarsus and the metal rings at the left tarsus, but there are exceptions.

note 5 : A few look-alikes with yellowish legs (hybrids as well as pure Yellow-legged Gulls) were cr-ringed as well.