A beautiful amelanic Common Chaffinch on the winter feeders of the Urretxindorra school in Muxika

Amelanic male Common Chaffinch (Fringilla coelebs)

During the ringing session at the school of Muxika within the project of the monitoring of wintering passerine populations at the countryside, we had a fantastic surprise when we ringed this amelanic specimen of a male common chaffinch covered by such a spectacular feathers.

Male Common Chaffinch (Fringilla coelebs) with feathers of common color.

The natural coloring of the feathers is caused by a deposition of diverse pigments like melanin, carotenes and porphyrins. These substances and its combinations made up the variety of colors of the feathers. Furthermore, they have an important role in the coloring of the keratin microstructures that are created meanwhile the feathers are growing.

Details of the colouring of the common kingfisher (Alcedo atthis) and the common teal (Anas crecca)

The melanin is the principal pigment in the feathers and is responsible of the production of black and brown colors as well as the mixtures of both. Melanin in excess, can cause an abnormal black coloring of some specimens and in the same way, a lack of melanin can make the plumage turn totally white.

The partial amelanism is one of the most common anomalies of the plumage among the birds, and is caused by the absence of all the melanin in one part of the plumage. Therefore, it's often heard about a common blackbird with partial white plumage, or about a white tailed sparrow...

Wing coloration comparison

This should not be confused with albinism, since the albino specimens have lack of melanin not only in the feathers but throughout the body causing completely white specimens, with rosy parts, specially the eyes. However, the amelanic specimens have a normal eye color.

For all this, although partial amelanism is the most frequent feather abnormality in birds, keeps surprising us when we find such a beautiful specimens in one of our ringing sessions.