The night before last, we had our first real cold front of autumn push through, pushing overnight lows down to the 50s for the first time in months. I expected that yesterday would have been a big flight that would result in window collisions, but last night seems to have ushered in a bigger wave of migrants. I found two at the south face of the Noble Research Center this morning (providing additional evidence that the direction of the prevailing wind has little to do with where on the building birds will end up).
The first was this beautiful Clay-colored Sparrow (fat = 2):
Not far away was this Common Yellowthroat. She was very much alive, and I was happy to see her fly away strongly when I shooed her away from the building.
This bird was an ID challenge: She was very pale on the throat, breast, and belly, but her yellow undertail coverts were quite obvious. That pattern, and the fact that she was pumping her tail a bit, had me thinking she might have been a Palm Warbler. Her pale legs and the lack of white on the tail tips ruled out Palm Warbler, as did her lack of other plumage details that might have strengthened the link. Instead, she looks to me like a hatch year, female Common Yellowthroat, but from the “Interior West” according to Sibley: those are the yellowthroats that can lack yellow throats, unlike the eastern subspecies that should show a bright yellow throat in all plumages.