It was another big night for migrants here in the Southern Plains. I found dead Clay-colored Sparrows at the northeastern and southwestern alcoves, and a trapped Grasshopper Sparrow at the northwestern alcove.
Clay-colored Sparrow #1 was heavy with fat (=3) and looks to be a HY bird.
Clay-colored #2 had a fat score of 2, and some tiny red ants had colonized it by the time I found it. I left that one in place to check the removal rate.
The Grasshopper Sparrow was trying desperately to fly east from the northwestern to the northeastern alcove. It was really wearing itself out. Thankfully, it was easy to point in the right direction, and it flew well away from the building.
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.
On a cloudy morning after a nighttime football game that shone bright lights on low clouds, there were birds left behind at the Noble Research Center. The first I found was this hatch-year Clay-colored Sparrow (fat = 2):
Then there were 3-4 birds trapped around the north entrance, including a House Wren. Is this the same little guy hanging around for weeks?
There was an obviously stunned Orange-crowned Warbler as well. The bird was sitting low and unresponsive, but it perked up when I picked it up.
The bird looks okay above. Had it remained this way I would’ve counted it as merely “trapped”. When I set it down, however, the bird did not fly away and it actually had trouble standing. For cases like this – in which a trapped bird has trouble standing – my policy is to consider the bird as a casualty. I’ll be interested in checking tomorrow to see if my suspicions are correct.
Yesterday’s Clay-colored Sparrow has been removed.
This Clay-colored Sparrow was being gnawed by a cricket this morning. Gruesome.
The north entrance and northwest alcoves were deadly again last night. This time the victims were an ASY female Black-and-white Warbler and an AHY Clay-colored Sparrow. The Dickcissel and Lincoln’s Sparrow carcasses have been removed.
Clay-colored Sparrow at the northwest alcove
Female Black-and-white Warbler at the north entrance.
Casualties piling up at the Noble Research Center
ASY-U, fat = 1
With sample sizes so small, any repeat of the same species in a week looks like a pattern. Here’s what eBird reveals about Clay-colored Sparrow migration this spring:
February 2012 records:
Yep, it sure looks like Clay-colored Sparrow migration kicked in this month, with birds passing right through Stillwater.