Excerpt on abinism and other plumage abnormalities. www.birdwatchireland.ie



A number of other plumage abnormalities occur, but much less
commonly than albinism. These are:
• Melanism Melanistic birds have an abnormal amount of dark
pigmentation. Several species have very rare dark phases, e.g. Buzzard
and Woodcock and others occasionally show signs of melanism (though
beware of oil-stained seabirds!). Pheasants seem to be the most
susceptible to melanism.
Erythrism Birds with erythrism have an excess of red pigmentation,
the best known example probably being the rare ‘hepatic’ phase of the
female Cuckoo.
Xanthochroism involves the loss of darker pigments and abnormal
retention of yellow pigment, and it has been recorded in
Wood Warbler and Yellow Wagtail.

Leucism Leucistic or ‘dilute’ birds are abnormally pale or ‘washed out’
looking. This plumage aberration is perhaps more frequent than any
except albinism, though still very unusual.