three juvenile Sabine's Gulls at Crowley Lake on 7 October

Observers: Jon Dunn and Andy Zdon
Date: 10/08/2007
Time: 03:16 PM -0400

Yesterday, Andy Zdon and I birded Long Valley, including Crowley Lake. At the north end of Crowley Lake Drive we found piles of Yellow-rumped Warblers and a variety of other birds, including an immature male Townsend's Warbler. At Crowley Lake we had a Horned Grebe (good close views) and three juvenile fresh plumaged Sabine's Gulls that were almost at our feet (photos to follow later). What intrigued me about them was that two were largely gray and the other was decidedly brown above and on the chest sides. The difference was dramatic, especially when both types were together. So, what's this all about? Several possibilities come to mind.....individual variation, possibly color morphs within the same population, or possibly geographic variation is involved. Perhaps the browner bird was younger and the gray birds were a bit more faded, but I wonder about that as the gray ones looked so fresh with complete pale fringes. We had the three Sabine's and the Horned Grebe at the east side of the mouth of the McGee arm. JLD

Grayer juv:

Browner juv:

Both together (grayer on left, browner on right):