Dear Barry and Tweeters,

Barry brings up a good point.

It is interesting how the term "leucistic" seems to have replaced "albinistic."

There is an article on albinism in John Terres's 1980 "Encyclopedia of North American Birds." The term "leucistic" is barely mentioned; it is glossed under a separate article about color of feathers. The brief reference to "leucism" assigns this term to paleness of plumage, rather than to whiteness.

In the article on albinoes, "albinism" of various sorts and degrees is said to refer to whiteness of plumage, skin, or eyes.

According to Terres, a blackbird with, say, two white primaries on each wing, would be called a partial albino.

Terres also mentions a type of albinism called "incomplete albinism." The definition that Terres gives for this condition is not clear to me, because it seems to be a synonym for "leucism."

It might be added here that, in dictionaries from the early and mid 20th century, "albinism" and "leucism" were considered synonyms--but "leucism" is omitted from most of those dictionaries, unless one finds an unabridged version. That term must have been rarely used.

Thus it appears that, some time in the mid-20th century, biologists sought to refine their terminology. Albinism was reserved for cases involving white body parts that lack melanin for whatever reason. Leucism was set upon as the term to use in cases of pallor of such body parts.

However, it seems that nowadays there is a studied reluctance to use the "A-word" for any bird that does not have pink eyes and all-white plumage.

Yours truly,

Gary Bletsch

?Near Lyman, Washington (Skagit County), USA?garybletsch at yahoo.com?Mentre che li occhi per la fronda verde
ficcava ?o s? come far suole
chi dietro a li uccellin sua vita perde, lo pi? che padre mi dicea: ?Figliuole,
vienne oramai, ch? ?l tempo che n?? imposto
pi? utilmente compartir si vuole?.??


--- On Fri, 4/15/11, Barry Ulman <ubarry at qwest.net> wrote:

> From: Barry Ulman <ubarry at qwest.net>
> Subject: [Tweeters] The Term "Leucistic"
> To: "Tweeters Bird Web" <tweeters at u.washington.edu>
> Date: Friday, April 15, 2011, 9:58 PM
> Hi Tweets,
>
> ??? For the last several years or more, I
> have seen people (including myself) refer to birds with
> abnormal white patches in their plumage as "leucistic". In
> the past it seems that such birds were called "partial
> albino". Are leucistic birds the same as partial albino
> birds, or are we talking about a whole different
> phenomenon?
>
> ??? Barry Ulman
> ??? Bellingham,
> WA._______________________________________________
> Tweeters mailing list
> Tweeters at u.washington.edu
> http://mailman1.u.washington.edu/mailman/listinfo/tweeters
>