Common Tern

Combination of :
* dark-green ring with a white 2 numeric code (on left leg).
* red ring above metal ring (on right leg).

note 1 : used codes are 00 till 99, excluding doubles e.g. 69 & 96, 86 & 98.

note 2 : from 2015 onwards a red ring above the metal ring (on right leg) will be added.

note 3 : this is used in order to distinguish from an illegal Spanish project.

note 4 : birds ringed in Warwickshire, UK.

note 5 : 

Yellow ring with a black three alpha-numeric code, starting letter 'F' followed by two numbers (on one leg) and metal ring (on the other leg).   

note 1 : Common Terns are ringed as nestlings on a large breeding platform at Lake Starnberg, Bavaria, Germany.

note 2 : 

2 rings (without code) on right tarsus (usually on right, occasionally on left) and aluminium ring on left tarsus (usually on left, occasionally on right) (adults/juveniles).

note 1: before 1995 : only aluminum rings with code on left tarsus.

note 2: 1995 : light-green and white (both at the top as well as at the bottom) and green-yellow.

note 3: 1996 : no colourrings, only aluminium rings with code on left tarsus.

note 4 : 1997 : green at the top and yellow at the bottom (exceptional opposite).

note 5 : 1999 : some 600 juv. birds have been marked with a ring (green at the top and yellow at the bottom).

note 6: in 2000 only ad. birds have been marked with colourrings.

c-ring (without code) on one leg.

note 1 :

Combin ation of c-rings : 1 c-ring (on right tarsus) and 2 c-rings (on left tarsus).

Combination of  c-rings : 4 colours, including a metal ring.

note 1: 1 ring with two colours on either tarsus.

Combination of c-rings.

Combination of 1 colour ring and metal ring (c-ring can be either tarsus).

note 1: birds are ringed at the Starnberger See - colony, Bavaria, Germany ;

- used codes are in 1999-2003 : 1 c-ring on right tarsus and 1 steel ring (Radolfzell) on left tarsus.

- used codes are in 2004-2005 : 1 c-ring on left tarsus and 1 steel ring (Radolfzell) on right tarsus.

note 2: birds are ringed at the Ammersee - colony, Bavaria, Germany.

- used rings are in 2003 : 1 c-ring on right tarsus and 1 steel ring (Radolfzell) on left tarsus.

- used rings are in 2004-2005 : 1 c-ring on left tarsus and 1 steel ring (Radolfzell) on right tarsus.

Combination of 3 c-rings (2 c-rings on left leg).

note 1 : all birds ringed in Britain & Ireland.

note 2 : used colours are : white, yellow, red, light-green, light-blue, dark-blue.

combination of 2 c-rings : 1 c-ring (on right leg) and a black and white striped ringed above the metal ring (on left leg).

note 1 : all birds ringed in Britain & Ireland.