Greetings all,
I have finally emerged from my food coma and found some time to poke around the
web looking for pale-faced Western Grebes. I didn't find any that show as much
white in the lores and around the bottom of the eye as Phil Kline's bird. I did
find a blog piece about a putative Western X Clark's hybrid that Steve Mlodinow
photographed a few years ago at Potholes Reservoir in e. Washington. It
features a bird with a straw greenish-yellow bill that is close to the normal
bill color of a Western, but shows a more extensive pattern of white around the
eye, with the eye about half in and half out of the white. If you scroll
through the article you will find a number of photos of the presumed hybrid
with direct comparisons with both Western and Clark's Grebes.
Here is a link to Mlodinow's article.
<http://birdhybrids.blogspot.com/2014/06/western-grebe-x-clarks-grebe.html>
http://birdhybrids.blogspot.com/2014/06/western-grebe-x-clarks-grebe.html
[https://3.bp.blogspot.com/-mi-ZeWPQr4U/U4pFP19NgKI/AAAAAAAAAFA/GDBHJsoVZVE/w1200-h630-p-k-no-nu/1462.jpg]<http://birdhybrids.blogspot.com/2014/06/western-grebe-x-clarks-grebe.html>
Bird Hybrids: Western Grebe x Clark's
Grebe<http://birdhybrids.blogspot.com/2014/06/western-grebe-x-clarks-grebe.html>
birdhybrids.blogspot.com
Steve gets to see a lot of these hybrids. He writes, "As a very rough estimate,
I'd say 2000 Western/Clark's Grebes breed on Potholes Reservoir, about 80 ...
I've also attached a couple of photos of a Western X Clark's hybrid that I
photographed on San Francisco Bay in May 2009. It has a more orangish-yellow
bill typical of pure Clark's. Clark's and Western Grebes hybridize somewhat
routinely. During a couple different grebe surveys on Fern Ridge Reservoir
Daniel Farrar and I saw occasional mixed pairs with dependent young. I've also
seen mixed pairs feeding young at Bear River NWR in Utah.
A couple notes of caution. While paler sides are more suggestive of Clark's,
whiter sides don't seem to be as reliable as either the amount of white in the
face or the bill color as definitive characteristics. Another thing to think
about is the fact that juvenile Western and Clark's Grebes are almost entirely
white-headed and it may be that the dark feathering wrapping below the eye
isn't as extensive in first-fall birds. When Daniel and I were doing fall grebe
surveys on Fern Ridge Res., we would see lots of very small hatch-year birds,
some still riding on their parents backs, well into September. On the surface
it seems awfully late for a young grebe to still be in a transitional plumage,
but given how late some of the Fern Ridge adults were apparently fledging
young, this could also be a plausible explanation for the appearance of Phil's
bird.
Dave Irons
Beaverton, OR
________________________________
From: obol-bounce@xxxxxxxxxxxxx <obol-bounce@xxxxxxxxxxxxx> on behalf of Daniel
Farrar <jdanielfarrar@xxxxxxxxx>
Sent: Friday, November 24, 2017 5:51 PM
To: pgeorgekline@xxxxxxxxx
Cc: davidcbaileyoregon@xxxxxxxxx; OBOL
Subject: [obol] Re: Clark's Grebe misidentified?
Interesting bird. The flanks also show a lot of white, another Clark's feature.
On Thu, Nov 23, 2017, 9:48 PM Philip Kline
<pgeorgekline@xxxxxxxxx<mailto:pgeorgekline@xxxxxxxxx>> wrote:
Thanks for catching this David. I actually thought this was a good candidate
for a hybrid, but the ebird app in the field did not give me that option (or at
least I could not easily find it). I thought the dull greenish bill color
ruled out a pure Clark's, but the amount of white above the lores was out of
the range of a typical Western.
Philip
On Nov 23, 2017 6:49 PM, "David Bailey"
<davidcbaileyoregon@xxxxxxxxx<mailto:davidcbaileyoregon@xxxxxxxxx>> wrote:
See the photo in this checklist:
https://ebird.org/ebird/view/checklist/S40664135#flag-75941061
I would call the grebe in this excellent photo a Clark's Grebe.
What do you think?
David
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