Robins of A Different Feather
The Leucistic Pigment Condition
This strange bird is really a robin.
It has unusual coloration because it lacks some pigments. Ornithologists call this condition leucistic (loo KISS tick).
One of the pigment this bird lacks is called melanin. Melanin gives feathers a brown-gray, or black tone. That is why the parts of this robin that should be dark are almost white.
A leucistic robin
Leucistic robin

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.

Normal robin coloration
Normal robin coloration

Find out more about variation in pigment and feather colors: