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.
The 40th casualty of 2019 indicates another unusually deadly year at the Noble Research Center on the campus of Oklahoma State University here in Stillwater, Oklahoma, USA. The fact that we’ve hit that benchmark in early September is especially disheartening. This hummingbird at the main north entrance earned the sad distinction of being number 40.
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.
This AHY female Painted Bunting in post-breeding condition (dried-up brood patch) met her end at the main north entrance, and was partially obscured in some bushes. This is why I don’t just check the ground; I look everywhere a bird body could end up.
Two migrants to kick off the second week of July is not what I’d call a good sign. So far, I’ve already documented 23 casualties in 2019.
Painted Bunting is the 3rd most abundant casualty on my list (26 individuals over 10 years). Only Ruby-throated Hummingbird (34) and Lincoln’s Sparrow (51) have been more often found at this site.
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.
I received a message last evening that there was a casualty at the southeastern alcove. Thanks to Thomas Hess for the heads-up and this photo from 3:37 pm on April 25:
I found it right where he said it was this morning: technically a 4/25 casualty but I’ll consider it 4/26 for my records as that is when I would’ve found it on my own. I moved the bird off to the side and it remains in place as of Monday morning, 4/29.
I haven’t analyzed this, but there have been many occasions that some unusual casualty will show up and another will appear on its heels – or on the same day. These events make me wonder about pairs migrating together or, at the very least, individuals from the same regions departing at about the same time and following similar routes. How else would we explain the 9th and 10th Orange-crowned Warblers hitting the same building less than 24 hours apart?
We had a serious cold front move through on November 11–12, dropping temperatures and a decent inch or so of snow. This was unusual in that we’ve pretty much had snowless winters for the past couple of years (a couple of ice storms and no more) and that it happened so early in the season. We were probably a week or so ahead of peak autumn color here; now all of those leaves are stuck to the trees and browning. Although brief, it was a hard freeze. Birds were caught a bit unawares too, as the results of today’s survey suggest.
First, there was a Lincoln’s Sparrow in an odd spot, along the northern exterior wall. This bird looks like it had been there for a bit, like maybe it had been buried under the snow and I had missed it.
Next was an Orange-crowned Warbler (AHY-male) in the northwest alcove.
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!