I would add that there are some subtle differences between McCown’s and Chestnut-collared. McCown’s has a more rectangular shaped head, there is a steep although short forehead, and then a flat crown. On Chestnut-collared the curve of the forehead-crown is more even. The bill is deep in McCown’s, but also very triangular (equilateral) in shape, almost like a Fox Sparrow. In some respects aspects of the bill and head shape and bill color, are more like a Snow Bunting which some studies suggest is a closer relative to McCown’s than the other longspurs. The facial pattern of Chestnut-collared also shows a shadow of the adult male pattern, in that there is a dark crescent at the lower rear of the ear coverts, and a dark triangle on the upper rear of the ear coverts; often the darkest part of the face on a Chestnut-collared are these areas and not near the bill or lateral throat stripes. This SF individual McCown’s has a buff chest area that is like a ghost pattern of the dark breast area of the adult male McCown’s.
Awesome photos, great learning by looking at them.
From: <SFBirds...> [mailto:<SFBirds...>] On Behalf Of Aaron Maizlish <aaron.maizlish...> [SFBirds]
Sent: Tuesday, October 10, 2017 6:45 PM
To: SFBirds <sfbirds...>
Subject: [SFBirds] McCown's Longspur Photos
Photos are likely starting to percolate onto eBird and Flickr, but I thought I would share with everyone some portraits from Crissy Field from this morning. I arrived at about 9:10AM, and like everyone else it seems I was able to spend some quality time with this great bird.
In case you want to enjoy the ID challenge yourself, I've posted eight pictures on my flickr feed - https://www.flickr.com/photos/amaizlish/ I found the National Geographic Guide to be more helpful than Sibley in this case. (Beadle and Rising helps too if you have it.) Note the pink bill with black tip - the plain auriculars, plain bare--streaked buffy breast (which is very bright on this bird) and the rufous-toned median coverts (not bright like a male.)
I'm glad it turned out to be a McCown's, since therefore this was also my ABA-Continental #600. Thanks Hugh!