[Tweeters] Arctic Loon on Port Angeles CBC Jan. 2 (Was Re: White
flanks on a loon does NOT equate to it being an Arctic Loon)
scottratkinson at hotmail.com
Mon Jan 4 11:25:52 PST 2021
Many observers have reported varied loons showing white flank patches at times,
especially when preening or when in feeding/diving mode. And then Red-throated
Loon can show white along the flank especially, and also tends to hold head/bill
upward. That said, the white flank on RT never seems to reach the fullest and
most symmetric expression as it does on Arctic. (And as we all know, RT does
not typically have dark plumage extending below the eye, RT giving off the "baby
face" impression, along with having a slimmer, paler bill than Pacific/Arctic).
This is all timely, because I just posted an Arctic Loon report from
Port Angeles, seen on the Jan. 2 CBC, to Ebird:
https://ebird.org/checklist/S78633096. No photo was possible, but
most details are given in writing there.
The slightly heavier bill & overall length, uptilted head/bill posture,
and side-profile silhouette of Arctic--what could be called overall
"presence" (or "gizz" in past parlance)--differ from Pacific Loon.
Brad is correct here in noting similarity to Common Loon. Overall length
of Arctic is about midway between Common and Pacific, but often comes
off as more like Common in the field, and Arctic seems to sit a bit lower in
the water than Pacific sometimes, likely reflecting a slightly heavier/
longer bird. The uptilted head/bill and side-profile
silhouette (for overall length, bill, head shape and back) are good
field-marks for Arctic, but a uniform, and full-length, white flank patch has
historically been considered important.
Back seems less neatly uniform and rounded than on Pacific, still again reminiscent
of Common Loon.
All of the above were evident with the Port Angeles bird, which was
at rest (and at side profile the entire time). Although I did not see the
Port Angeles bird fly off, Arctic seems a little heavier in flight than Pacific also.
My core experience comes from nearly 30 years of Russian Far East
visitation, including at-sea time; both Pacific and Arctic Loons are
common at times, such as migrants along s.e. Kamchatka, for
Nice comments by Brad Waggoner. And clearly not to discourage anyone from
looking for Arctic Loons. They are indeed rare and all the more reason to
look for them. Always best to post to Tweeters if you have found a
Take a look and decide what you think, based upon Brad's comments, about
the ID of these two Oregon loons, which I photographed over a period of
many years. (P.S. There was nothing 'highly' unusual about the posture of
either one.) Comments online or offline welcomed. To be continued.
Bob O'Brien Portland
It seems every winter there are a handful of reports of an Arctic Loon and “white flanks” are provided as the reasoning for the identification. The presence of white flanks is really not the identifying feature of an Arctic Loon. And all of our common expected species of loons can exhibit this feature to some degree depending on the individual bird depending on posture or behavior. The specific key feature to send one down the path of a potential Arctic Loon identification is an enlarged white “bubble” or oval area in the rear area of those white flanks. Then there are some subtle features such as a somewhat blocky head and larger bill than a Pacific Loon that will be of additional help. I think actually an Arctic Loon can tend somewhat more suggestive of a Common Loon than a Pacific Loon.
There are only a handful of WBRC approved records of Arctic Loon so it truly is a rare bird in Washington.
Good birding and Happy New Year!
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