January 2000 Mystery Birds

Thanks to everybody for the wonderful discussion. I loved it! The tanager is a Western and the sparrow is a Savannah. By coincidence both were photographed at the Point Reyes Lighthouse, the tanager 3 September 1983 and the sparrow 24 June 1982. These two photographs generated considerable debate after I showed them at the recent Central Valley Birding Symposium in Stockton.

The tanager was intended to demonstrate the gray on the underside of the tail found in Western and Scarlet as opposed to the yellow undertail of Summer Tanager. A nice example of the latter was photographed by Alan Hopkins and is on my photo gallery at the bottom of the page. An excellent example of a Scarlet Tanager in this pose is offered in the Quiz Bird solution of the October/November 1999 issue of Birders Journal where Matt Heindel points out the relatively shorter tail of Scarlet Tanager vs. Western. The difference is real but slight. Originally I thought the bird might not be identifiable to species from the photo, but I overlooked the trace of white wing-bar. Young Scarlet Tanagers occasionally show faint wingbars, but they are not this prominent. In my opinion, bill size is similar in the two species.

The sparrow photo was originally labeled "White-crowned Sparrow." In Stockton, I showed this photo as an example of a juvenile White-crown but did not discuss it further. Afterwards, several members of the audience questioned me about it. Steve Howell suggested it looked more like a longspur. Indeed the pink bill, strong outline to the ear-coverts and rusty tertials suggest Lapland Longspur. However, as pointed out in comments, the shape of the bird is wrong, especially the tail and primary projection as well as the leg color.

After studying the photo more critically, I now agree it is a juvenile Savannah Sparrow. I should have known! I have seen many individuals of this type at Point Reyes where the species breeds abundantly. The juveniles are much more brightly colored, and more coarsely patterned than adults and they do have an uncanny resemblance to Baird's Sparrow. The double whisker, formerly touted in some field guides as a mark for Baird's is not reliable. More important are the separate spots at the rear of the ear-coverts and the reddish scapulars of Baird's. The face and scapular pattern of the mystery bird are wrong for Baird's and correct for Savannah.

Once during a visit to the California Academy of Sciences, Steve Bailey was examining in-hand photographs of a sparrow banded at the Coyote Creek Riparian Station, Santa Clara County, in August. A visiting researcher who had studied Baird's Sparrows thought it was a Baird's, but after we compared the photos with specimens, it became clear that it was actually a juvenile Savannah, very similar to this month's mystery bird. Note also the slightly notched tail, with the central rectrices shorter than the outers. This should eliminate Song Sparrow which has a rounded tail tip and which does not show such a bright pink bill or pink legs. I think Vesper Sparrow invariably shows darker cheeks with a contrasting eye-ring and usually a much duller bill color. The narrow white fringes to the tail feathers are typical of young Savannah Sparrows. They are more visible on the upperside of the tail while the white outer tail feathers of Vesper Sparrow are normally visible only on the underside or when the tail is spread.

The race of Savannah Sparrow breeding at Point Reyes is supposedly Passerculus s. alaudinus (P. s. bryanti is a synonym), the same as those breeding in Salt Marshes around San Francisco Bay. However, the birds breeding in grasslands at Point Reyes seem paler to me compared to the very dark birds breeding in Salicornia marshes. The Savannah Sparrow subspecies in the San Francisco Bay region are sorely in need of a modern taxonomic review.

Again, I'd like to thank everybody for their courage in tackling these very difficult photographs. The original photos are below. To view public comments or join the fray by adding your opinion, click here. Have fun!

Photos © Peter LaTourrette and Albert Ghiorso.
All rights reserved.

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