[obol] Re: A Primer on Adult Gulls in Flight -- a photo gallery
- From: David Kollen <davekollen@xxxxxxxxx>
- To: llsdirons@xxxxxxx
- Date: Sun, 22 Feb 2015 22:46:35 -0800
Thanks Dave. As one of the ones with weak gull identification skills I find
this helpful.
Dave Kollen
Brookings, OR
On Sun, Feb 22, 2015 at 2:49 PM, David Irons <llsdirons@xxxxxxx> wrote:
> Greetings All,
>
> I can hear the roar of delete keys already, but for the eight of you who
> have followed along to this point, I'll share the link to a gallery of gull
> photos that I took yesterday. All of the photos show birds in definitive
> adult basic plumages. There are no mottled brown first-cycle birds, or
> ratty third-cycle birds with missing flight feathers or oddly retained
> feathers from prior plumage cycles. As gulls go, this is the fairly easy
> stuff. All of the photos were taken at the Port of Kalama, WA over about an
> hour span. I attempted to take them from a consistent angle, so the
> lighting conditions remained fairly constant. As you can see, trying to
> discern differences in the gray tones on the upper wings and mantles of
> these birds in the relatively bright midday sun was a fools errand.
>
> There are five species of white-headed, similarly gray-mantled, black
> wing-tipped gulls (Mew, Ring-billed, California, Thayer's and Herring) that
> occur across much of Oregon during the winter months. It is fairly common
> to be in situations where large mixed groups of these five species are
> flying by. Field guides will point out differences in mantle shade as a
> useful way to compare one to the others. However, in many lighting
> conditions (particularly bright sunny days) it ranges from difficult to
> near impossible for most of us to tell the difference between the back
> color of the lightest-mantled birds (Herring and Ring-billed Gulls) and the
> darkest-backed species (California and Mew). In the middle, we have
> Thayer's Gull, which most birders find confusing on several levels.
>
> The purpose of this photo gallery is to compare and contrast the
> black-and-white wingtip patterns in the adults of five superficially
> similar gull species. It works through the species from the smallest (Mew)
> to the largest (Herring). After several decades of gull study, I've
> developed a set of helpful clues that generally work well when I am faced
> with sorting through flyby gulls streaming along a river towards a roost
> site, or filing past a coastal seawatch. If this gallery of photos and the
> associated captions (roll your cursor over the large selected image to view
> captions) help even a few of you increase your comfort level with gulls in
> flight, I will consider this effort to be a success. If nothing else it has
> helped me reinforce and quantify the field marks that I've used to separate
> these species going back to the late 1970's.
>
>
> http://www.birdfellow.com/photos/gallery/943-wingtip-patterns-of-five-similar-adult-white-headed-gulls
>
> Dave Irons
> Portland, OR
>
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