Colour dyeing
A method of marking birds in which parts of their plumage are dyed a conspicuous colour, so that they can be recognised as belonging to a particular population and their movements can be followed. The dyed feathers will be lost at the next moult, so this is only a temporary method of marking. Colour dyeing is only suitable for relatively large birds, and has been much used on Bewick's Swans Cygnus columbianus.From Peter Weaver's Birdwatcher's Dictionary
Copyright © 1981 by Peter Weaver