Date: 10/30/17 10:19 am From: Lars Per Norgren <larspernorgren...> Subject: [obol] Gull ID chart
I can't claim to offer something better. The absence of "Olympic" Gull is significant as it's the most likely "taxon" birders will encounter much of the year in many of the most gull-rich places in Oregon. The white-headed gulls appear to be ordered by hue of mantle, with lightest at the top. With this in mind I would put Thayer's after G-wing and before California. Gull ID is intimidating, discouraging, a rich salad of pejorative descriptors. I think most beginners avoid it altogether, and often don't revisit it when their skills with other groups of birds have become finely honed. I think it was John Rakestraw who posted a series of photos and limited text a few years ago covering the six most likely species to be encountered in Oregon in winter. This was the most useful guide I've bumped into so far.
The near universal possession of smart phones makes these sort of things potentially accessible to folks in the field. How do brave, motivated souls find these fruits of individual initiative months or years later? At a fairly early age I encountered botanical keys and almost instantly gave up on them. A publisher in Berkeley put out two cheap little booklets, one for trees, another for shrubs, of the west coast. They were based on the dendritic key system, but free of technical vocabulary, included range maps and drawings on the same page. They were great. I wish I knew where they are now. Ultimately I learned most plant names at the elbow of someone far more knowledgeable and expect to continue to do so, although the number of good field guides on the subject has grown over the decades.
The chart in question describes adult gulls in breeding plumage. Precious few species of gulls are here in the breeding season. A highly motivated person might visit a gull roost or city park this November and find hundreds of adult gulls, all of them "white-headed"species, and none of them white headed. They are all sporting streaky gray helmets. This was a source of consternation to me when I consulted field guides in the sixties and seventies. Likewise, there may be a few "black-headed" gulls in the flock in November, and none of them have that characteristic hood.
A fat book came out a few years ago by Malling Olsen and Larsson-"Gulls of Europe, Asia and North America". I'm not sure I've seen it mentioned on Obol, I do know that I haven't found it very useful despite (or because of?)its 608 pages. A new edition is on the way, with lots more photographs. I hope it's worth the money, but more as a reference than an aid to ID.
As for the Unified Theory of Gull ID,Alan and Dave have already said it very well. This chart reminds me of the grammars I was taught in high school to learn French and German. The grammars were quite accurate, but they didn't help me much to learn those languages. In fact they became a handicap that I didn't get free of for several years. In retrospect I should have spent all that time watching soap operas in French or German. Maybe that wasn't an option as neither France nor Germany had commercial TV stations at the time. Now we've got the internett and could theoretically have a Gull Channel. Lars