There was a Gray Catbird at the south entrance today.
Birds on the move captured on Nexrad radar tell an important story on the evening of Sep. 23 to the morning of Sep. 24. First, watch migration blow up after local sunrise in the eastern US, and progress to the west.
As the night wore on, storms began to flare up in Oklahoma. Here in Stillwater those storms hit between 1:30 and 2:00 am on Sep. 24. As the storms expand, migration stalls: Birds put down to avoid the storms and for people on the ground, that’s a fallout.
Was there evidence of this fallout on the ground?
Well, there was a bonus Canada Warbler in that troublesome northeastern alcove of the Food and Agricultural Products Center. (This was in addition to a Mourning Warbler and a Wilson’s Warbler I found there on Sep. 21.)
There was a big flight of Nashville Warbler in Stillwater, too. Twelve were reported from Couch Park. I found one in the southwestern alcove and a Ruby-throated Hummingbird in the northeastern alcove.
As storms rolled through overnight, I assumed I might find a casualty this morning. There were two: a completely rain-soaked female Indigo Bunting in the southwestern alcove and a completely dry and fluffy Mourning Warbler at the south entrance under the rain protection provided by the portico’s overhanging roof. The latter was an AHY male with fat = 3.
Ahead of the official official ten-year anniversary of window collision monitoring at the Noble Research Center on August 20th, here’s a recap of my very first post from 7 September, 2009.
Those were heady days, indeed.
Here are some basic things I’ve observed and learned, August 2009–July 2019.
With some occasional help when I’ve been out of town, we surveyed the perimeter of the Noble Research Center for window-collided birds 2,141 times. I’ve generally run surveys every day (usually within about two hours of sunrise) during heavy migration periods in autumn and spring, scaling back to more like weekly surveys during the dead of winter.
Including 4 unidentified passerine remains, at least 414 individuals of 67 species died in window collisions at the Noble Research Center.
The most frequently encountered casualties were:
- Lincoln’s Sparrow 51
- Ruby-throated Hummingbird 36
- Painted Bunting 26
- Indigo Bunting 23
- Grasshopper Sparrow 20
- Clay-colored Sparrow 18
- Mourning Dove 17
- Nashville Warbler 16
- Mourning Warbler 15
Tenth is a four-way tie with 11 casualties each for Common Yellowthroat, Orange-crowned Warbler, Song Sparrow, and Yellow Warbler.
The spatial distribution of those casualties looks a bit like this:
Window treatments applied to selected panes in 2016 have, evidently, not contributed to a decline in collisions.
I plan to continue my monitoring at the NRC for as long as I can, and in the next 10 years hope to appreciably reduce the mortality here.
Although I consider July to be spring/summer, today’s casualty screams fall migrant. I was saddened this morning to find the pinnacle of avian evolution, Louisiana Waterthrush, at the far northwestern corner of the Noble Research Center.
This bird looked pretty good on the outside, but it was pretty rank. It’s Monday and the bird came in at some point between Friday afternoon and this morning. The relatively bob-tail has me thinking that it might be a HY bird, but I’m not sure.
After a bit of a slow start it did not take long to wrack up 20 casualties this spring. Today it was a “day 0” Yellow-billed Cuckoo at the main north entrance, meaning that it hit and was scavenged before I found it. Here again is a reminder of the difference between scavenging and removal: This bird was immediately scavenged, but it will likely be many weeks before all traces of its feathers are gone.
Every day there is a casualty discovered is cause for a twinge of sadness. Some are worse than others, however, especially when our personal biases are affected. My internal monologue on noticing any dead bird is a classic Midwestern ope, but today it escalated to motherf****r! as I got close enough to see what it was lying in front of a glass entry on the northwestern corner of the Noble Research Center. Yep, it was the pinnacle of avian evolution, a Louisiana Waterthrush.
I would be remiss not to mention the unusually rainy, cool spring we’ve enjoyed here in the Southern Plains, and this week flooding has turned deadly. Here in Stillwater, we topped 7″ of rain on Tuesday, with roads and schools closed. But our saturated soils didn’t result from one super storm. Check out these 30-days totals:
In fact, we’re a solid 20″ above average for the year:
This is a pattern of rainfall that often washes out waterthrush nests, built along the banks of streams. Having returned at the end of March, it could easily be the case that our local waterthrushes have attempted to nest, and been flooded out, at least three times. Perhaps a scenario like that might explain how a second-year (check out the feather wear) female (she at least attempted nesting – check out the brood patch) Louisiana Waterthrush ends up outside its territory in unfamiliar habitat to die at a window on the 23rd/24th of May? Is this a local movement to find a new territory less prone to flooding and give it another go? Is this a bird that has given up for 2019 and was on her way to molt and prepare for southbound migration while other birds are still streaming north? These intimate details of birds’ lives provide endless fascination for me and, of course, can lead to new and interesting directions for research that can help these birds better survive their forays into human-dominated landscapes.
Besides the feather wear and brood patch, there were a couple of other interesting things about this bird. It had fat in the furcular hollow! Floods don’t keep waterthrushes from foraging well, despite their threat to nests. Still, actually accumulating fat is hormonally influenced, and it strikes me as odd for a bird to accumulate fat outside of migration. This bird also showed obvious trauma to the tip of the bill, indicating a window strike at full speed. I can’t quite tell if the mark on the right pectoralis major is a contusion from collision or the beginning of the progression of brood patch loss. Many questions . . .
There’s a small alcove on a northeast corner of the Food and Agricultural Products Center across a parking lot from the Noble Research Center that often lures birds to their death. Today, it was this second year Summer Tanager.
My walk to the Noble Research Center revealed two window-killed birds outside the Food and Agricultural Products building, a male Yellow Warbler and Ruby-throated Hummingbird.
I also found remains (wingtips) of the Summer Tanager and Indigo Bunting that were scavenged from the southwestern alcove.
New casualties this morning were a SY male Painted Bunting in the southwestern alcove and a male Tennessee Warbler (9.5g, fat = 1) in the northeastern alcove.
It was a bitter milestone this morning as I encountered the 400th casualty on this project since I began regular monitoring in August of 2009.
Again, the long-term idiosyncrasies of this long-term monitoring have revealed something new. In this case, there have been 4 total Summer Tanagers I’ve recorded as window-kills since 2009. The first was on May 3rd 2013. That’s 6 years ago, and it was 4 years into the project. The last three were May 4th, May 6th, and May 11th of this year. So in one week in the tenth year of a project we’ve turned on its head what we thought we knew about Summer Tanager collision risk here.
This morning was a bit odd in that it’s rare to find window killed Summer Tanagers at the NRC, and that someone had moved yesterday’s Yellow Warbler. Now the warbler and tanager lie together at the main north entrance, and I can only assume that the tanager died very close by. (The Summer Tanager was a second-year male.)
To me, these window kills are saddest when the victim is an older individual in its prime. Case in point, consider this outstanding male Yellow Warbler from this morning that senselessly met its end at the main north entrance. Note, too how conspicuous these casualties can sometimes be. As soon as I got a glimpse of the north entrance I could tell there was a casualty there.
There were no new casualties on my survey from about 7:30 this morning, but then the sharp eyes of students Dalton Deshazer, Jake Rowland, and Corey Sage noticed this Yellow-billed Cuckoo in the southwestern alcove. (On my check the next day, the bird had been moved off the sidewalk and was much less conspicuous. It persisted until removal on May 5th.)
As a bonus, Corey Sage provided this photo of a trapped Cedar Waxwing, also at the southwestern entrance, later that afternoon.
It’s wonderful when spring finally springs, but that also means a return to dead birds. Today I found this wonderful male Ruby-crowned Kinglet at the southeast alcove, its life cut short en route to its breeding territory. This is the first casualty I’ve recorded at the Noble Research Center since last November. Even more significant, this is the first Ruby-crowned Kinglet I’ve recorded as a window-kill at the Noble Research Center, the 67th species casualty, and the 390th victim overall.
In a corner of the main north entrance to the Noble Research Center, I encountered this mystery today:
And I’m all like:
So let’s get to work on this.
First, this wasn’t here on Nov. 3 (Saturday), I did not check yesterday (Sunday), and when I found it today (Monday, the 5th) it had already been scavenged. I count examples like these as scavenging/removal on day 0.
Okay, so there’s a feather pile and a fruit pile. The fruit pile is on top of the feathers. The fruits show no signs of digestion, other than some of them having been opened and the pits are exposed. There is a single large pit inside a small fruit that is round and black with a highly glossy finish.
After much reading, comparing, consulting, etc., I’m pretty well convinced that these are chokecherries, Prunus virginiana.
My guess? I think our bird gorged itself on chokecherries before undertaking a migratory flight that, sadly, ended at a stupid window. The scavenger burst the bulging crop of this poor bird but had no interest in the fruits (in turn, feeding my opinion on the scavenger). So the remnants of this event are a pile of feathers and a pile of chokecherries.
Ah yes – the scavenger!
Well, we know that on campus we have skunks, foxes, opossums, raccoons, and feral cats as the most likely scavengers. The most likely of those to turn up its nose at a pile of chokecherries? I’d say cat. A cat scavenger would also be pretty well supported by the clean shearing of the flight feathers from the wings, visible here:
So what’s the bird? Well it’s clearly a meadowlark, but whether Eastern or Western takes some additional work. As with the fruits, I’ve spent a lot of time reading, consulting, and comparing. Perhaps the best resource for this task was a blog post from Kevin McGowan ca. 2000. (I also couldn’t get the USFWS Feather Atlas to load.)
Everyone knows that Western Meadowlark shows a yellow malar and in Eastern Meadowlark this is whitish. Without the bird’s head this character was of no use to me, however. In fact, there were just three feathers in the pile showing any yellow at all. Two other character differences are more relevant. First, both species have white outer tail feathers, but on Eastern the outer two are fully white and the third is mostly white. On Western the white is less extensive and even the outermost feather isn’t always fully white. In addition, Western looks paler overall than does Eastern, with the pattern on its tail and in the folded wings over the back appearing lighter brown/gray with blackish stripes. On Eastern, those same areas are darker brown with thicker blackish stripes often joined at the center of the feather creating a fern-like shape instead of distinct stripes. What do you think of these?
I’m leaning toward Western Meadowlark as the original owner of these feathers.
So I’m reporting today a pile of feathers that I think was Western Meadowlark, scavenged by a mammal I think was a cat, and that the cat showed no interest in what I think was a pile of chokecherries in what I think was the crop of the meadowlark.
Challenges, thoughts, etc? I welcome any and all!
This morning I found another White-throated Sparrow. In the last two days, the number of this species I’ve found since 2009 has doubled from two to four. We’ve also reached a yearly milestone with now 50 casualties for 2018.
For a bit of added sadness, I also happened upon this Song Sparrow at the Kerr-Drummond complex.
I found two Lincoln’s Sparrow victims today, both in somewhat odd places. At the Noble Research Center, one met its end at the door leading out to the eastern courtyard. This might be only the 2nd or 3rd victim in the courtyard since 2009.
I also occasionally check for window collision victims at the Food and Agricultural Products Center just to the west across the parking lot and Monroe St. This morning there was a Lincoln’s Sparrow in a tiny alcove where I’ve found birds in the past. This one I noticed by looking to my right as I drove down the street this morning.
Tough week here on campus as the casualties pile up.
Today, the northeast alcove had a Lincoln’s Sparrow and the project’s first Hermit Thrush. This now make casualties confirmed for 65 species at the Noble Research Center. The main north entrance claimed a Nashville Warbler, too.
Sex was undetermined for all three, but the Nashville Warbler was probably a female. The thrush and warbler looked to be after hatch year, while the sparrow was a hatch year bird. Thrush and sparrow had some fat lain down (I marked each a “one”), but I couldn’t find any fat on the warbler.
Nashville Warbler: 8.0 g
Lincoln’s Sparrow: 15.5 g
Hermit Thrush: 27.0 g
It was one of those tough days to be a Lincoln’s Sparrow on campus today. There were dead birds at the main north entrance and on the south portico. I examined the south portico bird which looked to be HY-U, with fat = 3. There were two more trapped Lincoln’s Sparrows I flushed from the main north entrance. They flew away strongly, showing no evidence of collision.
My first Lincoln’s Sparrow of the year showed up at the northwestern alcove today. I do much prefer to see them alive beneath my feeders. . .
Another feathered friend was very much alive, though stunned from a collision in southeastern entrance. He looked a bit shaky when I first found him, but he was actually fairly perky and difficult to catch. As it was chilly in the shade, I took the bird to a sunny spot near my office where he could more safely and quickly recover. Checking on the bird a bit later in the day, it was still there but flying strongly and looking to be recovering.
This bird was a wren of ambiguous affinity. It’s short tail was evocative of Winter Wren, but its plumage was a better match for House Wren. The bob tail might indicate a HY bird, but I didn’t spend much time examining its plumage for aging as my main concern was to make sure it had a safe place to chill out.
This morning I found the fifth dead Mourning Warbler on campus in the past two weeks: Four (including this one on the northwest alcove) at the Noble Research Center and one incidental find just across a small parking lot from the NRC at the Food and Agricultural Products Center.
For a bit of perspective on how unusual this is, i.e., Mourning Warbler is a secretive, migratory transient in Central Oklahoma that is far more likely to be found dead at a window than live on an eBird checklist, this was the 15th Mourning Warbler casualty I’ve found at the NRC since I began surveys in August of 2009. In comparison, I’ve only found 17 casualties over the same time period of the far more abundant and year ’round resident Mourning Dove.
This one was a hatch-year bird – so just a month or two old – with fat = 1.