Date: 5/5/19 5:17 pm
From: Paul Sullivan <paultsullivan...>
Subject: [obol] dimorphic Ruddy Turnstones
Yesterday I stopped at Fishing Rock State Park. 44.846101,-124.052222

I looked down on 2 Ruddy Turnstones foraging in the intertidal zone. This
is a species I don't see every year. Sometimes I pick up a bird at the port
dock in Bandon at the Shorebird Festival in the fall, sometimes not. I'm
usually just happy to see one.

What struck me about these two birds in spring breeding plumage was that
they were DIFFERENT. One had brighter chestnut patches on the wing and
back, and the head was WHITE WITH FINE BLACK LINES, while the other had
BROWN ON THE CROWN AND NAPE, and the wings were duller chestnut. I figured
they were a male and female, but I'd never seen this in 40 years of birding.
Back at the car I looked in Sibley's and National Geographic guides and
found only the breeding male illustrated. Luckily I had Dennis Paulson's
Shorebirds of the Pacific Northwest along and it showed the difference I had
seen. It was indeed a difference between the sexes.

Back home, I just looked through these guides and found they ALL showed only
breeding males, not breeding females:

Sibleys, National Geographic, Robbins, Stokes, Peterson's, Audubon's
(photographic), Am Bird Conservancy, Audubon Master Guide to Birding

The only common guide that shows the breeding plumage female is (drum roll)
Kaufman's Focus Guide.

Of course, Paulson's guide and Shorebirds by Hayman, Marchant, and Prater go
into more detail than the common general-purpose guides. These references
show the breeding female with her brown cap and nape.

Ya learn something every day.

Paul Sullivan

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