I found a Clay-colored Sparrow in the northwestern corner entrance to the NRC this morning, following the first big front of fall with frost near Woodward. I left the bird in place and it was scavenged by the next morning.
It was a bit foggy overnight so perhaps that contributed to the casualties I found today: An AHY male Nashville Warbler in the southwestern alcove (fat = 3) and a Clay-colored Sparrow in the south portico (fat = 2).
The one bright spot was the second Nashville Warbler. It was stunned but alive. On my approach it perked up and flew off strongly.
I found a trapped Clay-colored Sparrow today in the southwestern alcove. Upon release in the relative safety of a nearby shrub, the bird flew off another 5m or so to another shrub, where it perched strongly.
Less lucky was the Magnolia Warbler I found in the northwest alcove. This bird, a female with fat = 3, was just the second of this species documented on this project.
Yesterday’s Chipping Sparrow had me worried: it was flitting about so nervously trapped beneath the south portico that I assumed I’d find it dead this morning, from exhaustion if not from something else. Instead, I was greeted today by 2 Chipping Sparrows stuck in that spot this morning. Both are still moving fine and very active, but they’re going to have to figure out that flying down is their only way out.
As for the identification on these birds, I don’t have much to go on. From up in the rafters, I get only very quick glimpses of oblique angles and undersides. I managed these 2 photos today:
To separate autumn Chipping and Clay-colored sparrows, there are a few things on which to focus. In good light, I often rely simply on the warmer, buffier breast, flanks, and crown of Clay-colored to make the call, though I always prefer a clear view of the light brown rump, as opposed to Chippings’ gray rump. There is a gray rump visible in one of my photos (not one I posted), all but clinching Chipping Sparrow as the proper ID.
The head and facial pattern of Clay-colored is bold and conspicuously absent from these birds. Clay-colored shows a bright white mustache; this is absent on the birds in the photo. Also, the birds in the photo show dark lores. This is consistent with Chipping but not with Clay-colored. Thus, I’m pretty confident that these are Chipping Sparrows.
Science can be messy, especially when the subjects are living beings outside of a laboratory setting.
Here’s the latest illustration of this principle: If you had asked me last week if Indigo Bunting was a species that commonly shows up in my surveys for window-killed birds at Oklahoma State University’s Noble Research Center in Stillwater, I would have responded that I’ve found a few, but not an unusually high number of them. Indigo Bunting was the 10th most frequently recorded species on my surveys. From August 20, 2009 to May 4, 2014, I had only found 4 individuals of this species. So in nearly 5 years I had found 4. I would have been pretty confident in those 5 years of data, too. After all, that’s the value of long term ecological research. It provides a greater opportunity than in short term studies to identify patterns in data, including unusual events.
Speaking of unusual events, we’re in one now: Since, May 4th, I’ve found FIVE Indigo Buntings dead at the NRC. In five years I found 4 individuals; in the past week I found 5. Oh, and all 5 have been females. Today’s was an ASY female with fat = 0.
In other news, the Clay-colored Sparrow is now gone without a trace (it lasted 5 days), but the Indigo Bunting I left out yesterday has not been touched.
Lots to explain today. First, I’ve got to go all the way back to the Sprague’s Pipit from March of 2010 to find the last casualty near the northernmost entry to the Noble Research Center, i.e., the red dot on the map below:
I think the fact that casualties do show up in these odd places now and then simply highlights all the more how the various shapes presented by the Noble Research Center play a huge role in the pattern of collisions. I have conducted hundreds of surveys since 2010 without a single bird dying at that weird spot on the building, but other locations really do seem to draw them in. More on that in a bit. Here, though, is the unfortunate Clay-colored Sparrow I found at that spot this morning:
It’s not much to see, I know. That’s why I think I overlooked this bird for two days. It was in pretty good shape, but it wasn’t in immaculate shape. The bird was face down on the ground and had some dried mud splashed up on its back. This tells me that the bird likely came in Thursday morning during our overnight storms. Alternatively, it could have gotten wet from the sprinkler system and then subsequently dried. I’m going with the notion that it was a casualty during the storms and that I missed it for two days. Anyway, I left it in place to see how long it lasts.
The other two birds I found this morning were exhausted, but very much alive and apparently uninjured. The first was a beautiful female Painted Bunting trapped in the southwest alcove. She was slow enough for me to catch her and I released her into a tree away from the building where she flew on her own and seemed to perch just fine. She was carrying zero fat, so I’m hoping that she can find an easy meal.
I’m a little more worried about this Gray Catbird at the very-busy-this-week northwest alcove. This bird was active enough that I couldn’t catch it, but it also didn’t fly more than a foot or so off the ground and any farther than about 10 m at a time. I herded it out to beneath a tree where a robin was foraging so maybe it too will find some food quickly. I won’t count either of these birds as casualties – unless I find them again tomorrow. These are the days when I feel the greatest reward for the methodical daily surveys I do. Any day I can help keep a Painted Bunting going a little bit longer on this earth seems like a good day to me.
From two casualties since December to five just this week, it looks like migrant activity has picked up at the Noble Research Center. The northwest alcove was deadly last night for the third time this week, and I flushed a migrant Wilson’s Warbler from there this morning too. Today it was an unfortunate Clay-colored Sparrow (SY-U, fat = 3):
The southeast alcove claimed a victim as well: this second-year male Orchard Oriole (fat = 2):
This is the second of these beautiful orioles that I’ve found dead at the NRC, and both were SY males. Both also broke the tips of the bill on impact, illustrating both how delicate that structure is on this species and how birds hit glass with no idea that there is a barrier in front of them.
The Clay-colored Sparrow from Oct. 13 has been removed after 9 days.
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.
After warming back to 88F by yesterday afternoon, another Friday night brought another cold front (though no rain), and we are breezy and 50s this morning, with the wind out of the north. Again, the juniper hedgerow on the north side of the Noble Research Center is loaded with birds – several dozen in my estimation. Here’s the NEXRAD radar composite for about 6:50 this morning:
At the north entrance to the NRC I found one confused and trapped Clay-colored Sparrow. This Lincoln’s Sparrow (fat = 3) was dead at the northeast alcove.
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.
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.