[Mystery bird] Snow Bunting, Plectrophenax nivali, photographed in Minnehaha County, South Dakota. [I will identify this bird for you tomorrow]
Image: Terry Sohl, 19 January 2009 [larger view].
Photo taken with Canon 50D, 400 5.6L lens.
Please name at least one field mark that supports your identification.
Rick Wright, Managing Director of WINGS Birding Tours Worldwide, writes:
The angled commissure of emberizid buntings always makes them look like they’re smiling, don’t you think? The bright white plumage, pale bill, and terrestrial habit make this Snow Bunting easy to identify.
This January bird’s feathers are 5 to 7 months old, the product of a pre-basic molt undergone in July, August, or September; this species does not have a pre-alternate molt, assuming its natty black and white breeding “plumage” through abrasion: the dull tips of the feathers wear off over the course of the winter to reveal the contrasty colors beneath. We can actually see the worn state of the scapulars in this photo.
I believe that the bright white greater coverts visible here sex the bird as a male. I’ve never really been able to figure out how to age Snow Buntings in the field — pointers appreciated!