Combination of uncoded c-rings and metal ring.
note 1 : used colours are white, black, red, yellow, green, blue, purple, violet, orange, brown and grey. Also double colour rings (white-red, white-black, white-blue, yellow-black and yellow-red).
note 2 : since 2003 in the Picos de Europa National Park (NW Spain) 484 birds were ringed.
note 3 : bird are also ringed in High Atlas Mountains, Morocco ... of course with a different code as in Spain.
note 4 :