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Message: <blockquote data-quote="Chris Benesh" data-source="post: 1043860" data-attributes="member: 6775">Hi Niels,Sorry not to have responded to your comments before now.  You raise some interesting questions that were worth further pursuit.  First of all, let's explore the idea of a similar species.  There are some masked magpies (Cissa, Dendrocitta) out there, but none bear any resemblance to the mystery bird.  The bird differs in a variety of ways from either of the magpie-jays.  Equally important, the bird is seemingly identical in structure and plumage to birds of the Pica pica complex.  Pica hudsonia occurs naturally in the range of the mystery bird, so is presumably the species involved.  Ignoring the mask for a moment, one can compare the plumage of the mystery bird to that of other Black-billed Magpies and see that the distribution of dark pigment is identical in both.  But those dark areas on the mystery bird appear grayish where they should appear black or black with iridescent highlights.  Mystery bird:<a href="http://www.birdforum.net/attachment.php?attachmentid=111550&d=1193719430" target="_blank">http://www.birdforum.net/attachment.php?attachmentid=111550&d=1193719430</a>Black-billed Magpie:<a href="http://www.mdbrodie.com/birding/black-billed_magpie.jpg" target="_blank">http://www.mdbrodie.com/birding/black-billed_magpie.jpg</a>So the mask aside, we should be able to conclude that the bird is a Black-billed Magpie with a dilution of blackish pigments.  Curiously, in his article in Birding, Jeff Davis cites a 1995 article in the Edmonton Naturalist (23:21-23) by pigment guru Dr. Jocelyn Hudon titled Edmonton and its imperfect albino black-billed magpies.  It mentions that birds fitting Davis's definition of hypomelanistic have persisted in Edmonton since 1946.  I contacted Dr. Hudon and he confirmed that the mystery bird is indeed one of the "ghost" magpies that make up a tiny percentage of the magpies in and near the city of Edmonton.  He writes,"You might be interested to hear that Edmonton and area has several ofthese hypomelanistic magpies (see attached paper, which may be missingthe map). A public appeal for sightings of these unusual birds severalyears ago also turned up light magpies in Red Deer, Calgary and HighLevel in Alberta. Moreover, they go back at least 50 years ago.Please note that there is a great deal of variation in the lightness ofvariant magpies, some being quite light gray, others being much darker(like the bird being discussed on Birdforum). Clearly, genes other thanthe one mutated (i.e., the genetic background) are affecting itsexpression and the final phenotype (appearance)."I'm not sure if you've had a chance to read the Birding paper on abnormal pigmentation.  The primary reason for suggesting changes to the terminology is that the usage of conventional terms like albinism and leucism has been enormously inconsistent, rendering the terms somewhat meaningless.  For example the condition of the ghost magpie (hypomelanistic) has been termed "leucism, albinism, dilution, dilutism, ghosting, paling, isabellism, and isabellinism" according to Davis.  Clearly there is a need for convention in terminology.  Chris</blockquote>

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