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It's Not Black or White: another foray into abnormal pigmentation in birds (1 Viewer)

The latest issue of Birding magazine arrived in my mail box today and I was pleasantly surprised to find some interesting reading within. There has been a lot of discussion in various forums about what sort of terminology to employ when talking about abnormally pigmented birds. The terminology has been confusing and inconsistently applied for over a century, so that now there is no consensus as to the definitions of such things as albinism, partial albinism, leucism (not to mention how to pronounce it), etc. There have been several efforts to resolve inconsistencies, but none have generated consensus.

Now, along comes Jeff N. Davis to put us straight. In his piece Color Abnormalities in Birds: A Proposed Nomenclature for Birders, he approaches the subject with fresh eyes. Though it would have been nicer to see this sort of paper published in a professional ornithological journal (e.g., Auk, Condor, Ibis, etc.) where it might gain some acceptance in the scientific community as well, it has the potential to be a seminal paper on the topic. It seems well researched and comes with an extensive bibliography. Not only does he provide a new set of terminology, but the terms are well chosen to be applied specifically to birds, and each term selected to reflect the underlying cause of pigment abnormality.

Among the terms are:
total amelanism - absence of all melanin from the plumage, eyes, and skin.
partial amelanism - the abnormal absence of all melanin from parts of the plumage, eyes, skin, or all three areas.
hypomelanism - is the abnormal reduction of melanin concentration from the plumage, eyes, skin, or all three areas.
aeumelanism - the abnormal absence of eumelanin from the plumage, eyes, skin, or all three areas.
aphaeomelanism - the abnormal absence of phaeomelanin from the plumage, skin, eyes, or all three areas.
hypermelanism (including hypereumelanism and hyperphaeomelanism) - the abnormally high melanin concentration in the plumage, eyes, skin, or all three areas.
carotenism - abnormal carotenoid pigmentation for one of four reasons (outlined in the paper).

The paper has photographic examples of each type of abnormal plumage.

The article suggests that there are a few other, less common causes for pigment abnormalities outside the scope of the article. But the ones listed above would apply to the great majority of oddities encountered in the field. Unfortunately, the PDF of this article was not included in the online material at ABA <http://www.americanbirding.org/pubs/birding/archives/index.html>, so I would recommend getting hold of a copy of the journal. Birding 39(5):36-46.

Chris
 

Chris Benesh

So much work, so little time...so let's go birding
Hi Audubob,

Thanks for the comments. Glad to see that someone is reading the blogs!

Chris
 

Accipiter91

Well-known member
no problem...I like to pop in and read over the topics every once in a while...very good read and nice presentation! :t:
 

Carlos23

New member
Hola Chris,
it very, very interesting and it been always confusing to me the past terminology.
It is good that Jeff N. Davis is been working on this and glad you are sharing this important information with us.... I hope this information will go to an ornithological jurnal ,as you mention!...
 

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