Caspian Tern

White ring with a black three alpha-numeric code, starting letter "X".

note 1 : used codes are : X00-X99, XA0-XZ9 and X0A-X9Z.

note 2 :

Red ring with a white four alpha-numeric code (on onel ge) and metal ring (on other leg).

note 1 : first letters are A, C, F, H, K, M, R, T, U, Y.

note 2 : 

Red ring with white a 3 alpha-numeric code.

note 1 : first letters are : A, C, F, H, K, M, R, T, U, Y.

note 2 : 

Yellow ring with a black three alpha-numeric code (letter/number/letter).

note 1 : birds ringed by the Birdlife Alcyon project on the Ile aux Oiseaux in the Sine-Saloum National Park in Senegal.

note 2 :

Yellow ring with a black three alpha code one leg).

note 1 : used codes are Cxx, Fxx, Jxx, Kxx, Lxx and for the year 2015-2020 : Mxx, Nxx, Uxx, Pxx, Sxx, Txx.

note 2 : up to 2014, a total of 730 rings were delivered since 2008-2014.

note 3 :    

Combination of a c-ring and a coded c-ring.

note 1 : a partnership between Oregon State University, Real Time Research,
and the USGS - Oregon Cooperative Fish and Wildlife Research Unit.

Combination of c-rings (on both tarsi).

note 1 : a partnership between Oregon State University, Real Time Research,
and the USGS - Oregon Cooperative Fish and Wildlife Research Unit.

c-ring and metal ring.

note 1 :

Black ring (on left leg) with a white code KJnn : n is number. No metal ring.

note 1: birds are ringed in Russian Karelia.

Combination of c-rings.

note 1 :