Eurasian Tree Sparrow

Red ring with a white two alpha-numeric code (letter/number or number letter) (on left tarsus) and metal ring (on right tarsus).

note 1 : birds ringed in Antrim, Northern Ireland.

note 2 : 

Combination of :
* red ring with a white one numeric code (on right leg). 
* one or two c-rings above the metal ring (on left leg).

note 1 : red ring has this code : 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

note 2 : c-ring(s) : used colours are : green, blue, red, orange, pink, yellow, gray, white.

note 3 : project starts during 2026.

note 4 : 

Red ring with a white two alpha code (on left leg) and BTO-metal ring  (on right leg).

note 1 : birds ringed in Norfolk, UK.

note 2 :

Combination of :
* metal ring above 1 c-ring (on right leg).
* 2 c-rings (on left leg).

note 1 : a coloured ring with a stripe in the middle (white, black, red, dark-green, orange, blue and white) and another coloured ring (dark-green, blue, violet, red, white, yellow, pink, brown, black and orange).

note 2 : birds ringed in Catalonia, Spain.

note 3 : birds ringed since 2024.

note 4 :

Yellow ring with a black three numeric code (000 - 999) (on left leg) and metal ring  (on right leg).

note 1: birds ringed Northumberland, UK.

note 2 :

Black ring with white two alpha-numeric code (number/letter or letter/number) (on left leg) and metal ring (on right leg).

note 1 : used letters/numbers are : A, C, D, E, F, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

note 2: rings with starting letters "B" and "G" are not used.

note 3 : 2000 birds ringed between 2018-2025 in Burgenland, Austria.

note 4 : 

Yellow ring with black two alpha-numeric code (number/letter or number/letter) (on left leg) and metal ring (on right leg).

note 1 : used letters/numbers are : A, B, C, D, E, F, G, H, I, J, K, L, M, N, O, P, Q, R, S, T, U, V, W, X, Y, Z, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9.

note 2 : 2000 birds ringed between 2018-2025 in Burgenland, Austria..

note 3 : 

Brown ring with a white two alpha code.

note 1 : used codes are : letter/letter.

note 2 : birds ringed in Norfolk, England.

note 3 :

Black ring with a white two alpha code.

note 1 : codes used: B/letter or G/letter.

note 2 : birds ringed in the UK, North Yorkshire.

note 3 :

Red ring with a white three alpha-numeric code (on left tarsus) and metal ring (on right tarsus).​

note 1 : used codes are : A, B, C, D, F or H / letter / number or A, B, C, D, F or H / number / letter.

note 2 : birds ringed in Glasgow area, Scotland.

note 3 :