Hi Dave and all —
Thanks for this posting, and yes, please do let us know what you hear about
these birds. I often feel confused about where to draw the line with atypical
sapsuckers, and always seek to learn more.
On a few occasions when I have had trouble with sapsucker photos in my review
areas, I have consulted with Steve Shunk (steve@xxxxxxxxxxxxxxxxxxx). I've
found his responses to be very helpful, and he has told me he’s happy to invest
time helping eBird reviewers on this topic.
With so many photos pouring into the MacCaulay Library these days, at some
point it might be useful for someone (not me!) to go through all the atypical
sapsucker photos and try to make sense of them, systematically and all together
at once with a large sample size. Patterns can become apparent and new things
can sometimes be learned as a result. Bryce Robinson recently did this with
Flicker intergrades and gave an interesting talk at this year’s WFO meeting,
for example.
Jay
On Dec 20, 2021, at 6:13 PM, David Irons <LLSDIRONS@xxxxxxx> wrote:
Greetings all,
In recent days I've been sent photos of two different presumed hatch-year
(HY) sapsuckers with somewhat ambiguous features. In both cases I think that
there is at least moderate evidence that suggests they are hybrids rather
than "pure" Yellow-bellied and Red-naped, which is how they have been
identified. One of the birds is from Texas and the other is currently being
seen in Tillamook County. I have reached out to Marshall Iliff and Shawn
Billerman for some guidance on these birds (see my email to them is below).
Shawn did his PhD studies on how Red-breasted, Red-naped and Yellow-bellied
Sapsuckers interact across their broad zones of contact during the breeding
season. These three species are all known to interbreed with one another and
their offspring are fertile and can produce backcrossed hybrids.
It is of course well-known that Red-breasted and Red-naped sapsuckers cross
breed rather freely along a long suture zone of contact that extends from
northern California into British Columbia. Probably less known and certainly
less publicized is that Red-breasted and Yellow-bellied sapsucker breeding
ranges overlap and they also hybridize, to what extent is poorly known. I
strongly suspect that the Texas bird in the attached photo is a
Yellow-bellied Sapsucker X Red-breasted Sapsucker hybrid, even though local
birders there have been identifying it as a "pure" Yellow-bellied. In my
opinion the back pattern is wrong for Yellow-bellied and I can't find any
evidence that pure Yellow-bellieds ever show irregular patches of red through
the auriculars. In my experience this sort of random red bleeding across the
black and white facial striping is found strictly on birds that have some
Red-breasted Sapsucker ancestry.
The Tillamook County bird is much more ambiguous. Aside from quite a bit of
what appears to be retained juvenile plumage on the underparts, which most
references say should have been replaced by this date, this bird looks pretty
good for Red-naped Sapsucker. It shows no random red in the face pattern,
which is typically evident in in any Red-naped X Red-breasted hybrid. That
said, the bird does appear to have a little bit of red on the sides of the
upper breast, which should not be the case with a pure Red-naped. I can
certainly appreciate how those who have seen this bird are calling it a
Red-naped. It may well be a F2 or F3 hybrid with Red-breasted ancestry from a
few generations back.
Given how challenging it is to be certain of the parentage of some apparent
hybrids, we can't assume that all hybrids seen in Oregon are Red-breasted X
Red-naped. It is certainly plausible, and in my opinion likely that some of
the apparent hybrids we get here are Red-breasted X Yellow-bellied crosses.
At this point we are not really left with a good option when it comes to
slotting a bird for whom the parentage is murky. I would like to see Marshall
add "Sphyrapicus hybrid" to the taxonomy to provide a better option than just
listing them as "sapsucker sp." In both cases I feel confident that these
birds are hybrids (perhaps F2 or beyond), but my level of confidence about
their parentage is much lower.
I hope to get some good feedback from Shawn and perhaps Marshall. If I do, I
will certainly share it. Feel free to forward any troublesome sapsuckers that
you find in your review queues. Years ago when I was doing regional editing
for North American Birds Steve Mlodinow and found that quite a few of the
Red-naped Sapsuckers being reported west of the Cascades were RBSA X RNSA
hybrids, hence reports of them need be reviewed carefully and probably should
be supported by photos before we accept them.
Dave Irons
From: David Irons
Sent: Monday, December 20, 2021 9:48 PM
To: Marshall Iliff <mji26@xxxxxxxxxxx <mailto:mji26@xxxxxxxxxxx>>; Shawn
Billerman <s.m.billerman@xxxxxxxxx <mailto:s.m.billerman@xxxxxxxxx>>
Subject: Two interesting sapsuckers and how we slot them in eBird
Greetings Shawn and Marshall,
In the past five days my opinion has been solicited about the parentage of
two apparent Sphyrapicus hybrids. One was sent to me by Mary Gustafson (image
attached). This bird is wintering Laredo, TX and many local birders there are
identifying it as a "pure" Yellow-bellied.
The second, which can be viewed by doing current image eBird search of
"Red-naped Sapsucker" (Tim Janzen S99157903
<https://ebird.org/view/checklist/S99157903>) is being seen in Tillamook,
Oregon and it has been identified as a Red-naped Sapsucker.
In both cases the birds seem to have significant retained juvenile feathering
on the underparts. Based on my understanding of molts, only Yellow-bellieds
should still be showing extensive juvenile body feathering this far into
December. That said, when I search December eBird photos of apparently "pure"
Red-naped Sapsuckers I am finding lots of photos of birds that show either a
complete lack of a black breast shield/throat frame or a mottled version of
such and patterns on the underparts that are suggestive of retained juvenile
feathering rather than a more adult-like plumage.
On the Laredo bird the red in the face behind the eye is bleeding across the
black auricular and into the white supercilium and moustachial stripe, which
to me suggests at least some Red-breasted Sapsucker lineage. Further, the
narrow trough of the whitish barring on the back is more like the pattern
shown by a Red-breasted and not nearly as extensive as I would expect on a
pure Yellow-bellied. I told Mary G. that I thought it was likely a YBSA X
RBSA even though it shows no apparent red on the breast. This bird also shows
no red on the nape, so I am inclined to think it's not a RNSA X RBSA.
The Tillamook bird is interesting in that it looks mostly like a Red-naped
even though it has a more juvenile-like pattern to the underparts. I am not
seeing any red in the face pattern, which in my experience is pretty much a
given with RBSA X RNSA hybrids. However, there is some red on the sides of
the upper breast outside of the expected red on the throat, which does
suggest some Red-breasted ancestry. Is there evidence of RBSA X RNSA hybrids
pairing with YBSA and producing offspring?
My first three questions are primarily to you Shawn. Can and do
HY/first-winter Red-naped Sapsuckers retain more juvenile feathering than
some of the recent ID articles on this topic suggest? Secondly, do some RBSA
X RNSA hybrids not show any unexpected red in the facial pattern? Finally,
can apparently "pure" Yellow-bellied Sapsuckers occasionally show unexpected
red in the face pattern? I can't find any evidence of such in the eBird photo
galleries.
The real challenge with birds like these is how do we account for them in
eBird checklists. As a reviewer I would not accept either of these birds as
reported. Further, based on some of the age-related confusion discussed
above, I would be equally reluctant to accept them as definitive hybrids of
known parentage. I think at best these birds can be treated as "Sphyrapicus
hybrids," but there is no available taxonomic slot in the eBird taxonomy to
put them into. With hybridization between RBSA and RNSA being arguably more
studied and better known among rank-and-file birders than hybridization
involving YBSA, I think birds that do present as hybrids (particularly in
here in the PNW) get identified almost by default as RBSA X RNSA with no real
consideration of potential YBSA ancestry. The more I look at these birds
(like Cackling Goose subspecies) the more uncertain I become about what I
looking at.
I look forward to your thoughts on these birds and perhaps some better
guidance on how to deal with eBird reports of presumed hybrids with ambiguous
outward appearance.
Dave Irons
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