While I agree that an individual with access to a series of specimens
may be more qualified to make a call in identification, what bothers me
most about Dan Gibson's comments is that we haven't seen an analysis.
What characters is he using to determine the identity of the birds in
question? Is it the amount of black in the tail? That's the only
character he states in his letter, but the literature clearly
demonstrates that the amount of black at least in the female plumaged
bird at Iona Island is well within the range of what can be expected for
Mckay's. How can all of the literature be wrong since at least some are
referring to a large series of specimens as well? I've wondered if
anyone has access hybrid specimens, especially those taken in winter.
Nearly all references I've seen describing apparent hybrids involve
breeding males. I'm also curious as to Gibson's real field experience
with McKay's and Snow X McKay's individuals. Statements such has " I am
sure Dan has seen McKay's Buntings in life quite a few times, as opposed
to the two birds (or maybe one)..." are not helpful- it's akin to
putting words into his mouth. Regardless I'd like to know what
characters are being used to make the call and thus influence the rest
of us as to what we are calling a McKay's Bunting or not. If anything it
would be beneficial to those of us without access to specimens to make
field determinations in the future regarding this species pair.

I've also been seeing statements regarding hybridization between McKay's
and Snow Buntings, but as far as I have been able to determine, no one
has looked into this question in any real level of detail. There are
numerous vague references to hybridization, even in recent emails, with
such contradictory qualifications as "rare" or "rather frequent". If
anything, our understanding of the close relationship of McKay's to Snow
is very lacking. Mitochondrial DNA studies put the divergence as very
recent and if one trusts the percentages rule in determining phylogeny
in birds then McKay's should only be a well-marked subspecies of Snow. I
don't put much faith in the % rule, since it relies on an average rate
of evolution or the evolutionary clock which many believe isn't a true
reflection of the evidence- evolution may proceed rapidly or slowly
depending on many factors- this is a long topic all by itself and a huge
tangent.

So in summary- I think it's unreasonable to base our (the collective
our) identification on an expert without good explanation, especially
when all we have to rely on is the literature to make our own
determinations. I will get off my soapbox now!

All the best, Alan


--
Alan J. Knue
bluejay at surfbirder.com

Seattle, WA, USA