Occasionally
a bird doesn't produce some pigments. In the example above the
robin either doesn't produce melanin
at all,
or
produces only small amounts. What parts of the robin's coloration
are affected?
Notice: The leucistic robin does have a
reddish breast. Compared to a normal robin, the color is a bit
washed out. The beak doesn't have the
dark shadings of a normal beak. But
the
bird DOES produce the pigments responsible for the yellow bill
and red breast. This is one reason we know it is not a true albino
robin.
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