Matt,
The release date on Steve Chunk’s woodpecker book in May 10, so probably
Steve is the only one to have it at this point. I will forward your
comments to him, but I believe he is in Mexico now, so it might be a little
bit before he can chime in.
Tom
From: obol-bounce@xxxxxxxxxxxxx [mailto:obol-bounce@xxxxxxxxxxxxx] On Behalf
Of Matthew G Hunter
Sent: Sunday, March 06, 2016 3:50 PM
To: obol
Subject: [obol] Wasco Sap--some context and info
Hi Jen and All,
I agree with Jeff Hayes, and Dave and Shawneen! Haha!
My earliest and latest explorations in Oregon have involved the Douglas
County area, where we get more influence from the "southern" characteristics
of Red-breasted Sapsuckers (the southern ssp daggetti), which tend toward
features reminiscent of Red-naped, so I have been curious about sapsuckers
for a long time, and I have to say, they have made a full mess of
themselves. :-)
Your bird has mostly very strong features for the northern subspecies
(ruber) of Red-breasted Sapsucker, such as:
*Mostly full read head w/no pale face stripes
*Good red hood that comes far down the upper breast, with no hint of
blackish underneath (the latter often seen in hybrids).
*Predominantly dark across back, with limited white bars in rows, vs
widespread.
*Although very unreliably judged, it does appear to be a more "hefty"
bird--large body and smaller head--as in ruber.
The signs of hybridization that the eBird reviewer and Dave and Shawneen
pointed to were the blackish on the side of the head and nape. These
features are not unusual on daggetti, but the bird doesn't seem to have any
other features of intergradation with daggetti (such as hints of pale
mustache lines); also, daggetti are typically found from SW Oregon and south
and don't seem to wander much. Could these dark marks be within range of
variation for ruber? Well, I wish I had a layout of what a taxonomist
specifies as the range of variation in ruber. There may be such a thing, but
I don't have it (anybody have Steve Shunk's new woodpecker book? Anything in
there?). However, we do have a good sample of photos of sapsuckers in eBird.
If you use the Explore Data/Species Maps feature, you can set the time
period to winter (say Dec-Feb, to match relevant plumage/wear), navigate to
the pacific northwest, and select Red-breasted Sapsucker, then click on the
Explore Rich Media box on the right. Then you have to find the photo in each
of the checklists. Some are helpful, some are not. (eBird is eventually
going to have a more sophisticated search mechanism.) I "randomly" breezed
through several dozen of these of these from SW BC and western Washington
and NW Oregon, Dec-Feb. My rough estimate is that over 50% of the birds
labeled "Red-breasted Sapsuckers" have dark areas on the side of the head
similar to your bird (the rest with less dark), and maybe 20% or more have
some dark and/or light coming up the lower nape from the mantle, similar to
your bird. There are also maybe 20% that have really solid red heads with
very little or no markings encroaching the hood from the back, though most
have at least a much smaller darker area on the side of the head.
So, what are all these birds? Is this variation "normal" for Red-breasted
Sapsucker? Or are "pure" ruber Red-breasted Sapsuckers supposed to have
completely solid red hoods with no encroachments of dark feathers
whatsoever, and over half the Red-breasted Sapsucker photos stored in eBird
are hybrids? I don't know for sure.
If you have the time, energy and interest, I would recommend researching the
question more yourself and please get back to us with what you find out. I
would recommend a few initial steps:
1. Check out Steve Shunk's article on hybrid sapsuckers from Birding (link
below). I don't think it will answer the question with regard to your bird,
but it is a place that has references that give you some names of people who
have worked on the subject. These are people you could track down. And/or
perhaps someone on this list can suggest someone to query. Or maybe Steve
will read this and give some input or further contacts (find him at
http://www.paradisebirding.com/)
http://www.paradisebirding.com/Paradise%20Birding%20PDFs/steve%20shunk%20pub
lications/Shunk%202005%20Sapsucker%20Hybrids.pdf
2. Ask for input from the ID Frontiers list. You can subscribe here:
http://listserv.ksu.edu/web?SUBED1=birdwg01
<http://listserv.ksu.edu/web?SUBED1=birdwg01&A=1> &A=1
Maybe someone else on the list has some additional tips/leads for Jen?
I hope that helps. The pursuit makes the answer more valuable.
Matt Hunter
Melrose, OR
P.S. On the hybrid topic in general, I'm not aware of any standards/cutoffs
that have been established for labeling something as hybrid versus just
using a species epithet in eBird. One obvious "problem" would be with
Western and Glaucous-winged Gulls. Are there any "pure" birds on the Oregon
Coast? Well, that depends on your definition. Phenotypically, some look
pretty good. But how good is good enough? How many gray flecks on the head
of an adult, spring, Western Gull make us obligated to call it a hybrid? 1?
100? 1000? I don't have an answer to that, but when I record gulls in my
eBird reports, I mostly record full species, and only record as "hybrids"
those that are fairly quickly noticeable as such. This means that some of my
reports of full species are undoubtedly backcrosses to some degree or
another, but the situation in the PNW is known and that is about all we can
expect from reports from field observers. Same with sapsuckers. Efforts to
well-document subtle hybrids would certainly be gratefully welcomed in any
reporting medium, but certainly not expected for more reports of these
birds.
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