Tough morning with three casualties at the Noble Research Center: there was a Ruby-throated Hummingbird in the southwestern alcove and flanking Wilson’s and Yellow warblers at the main north entrance.
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.
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 . . .
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!
Well, here we go. Today marks the end of my 9th year conducting spring/summer monitoring for window-killed birds at the Noble Research Center. Tomorrow I begin year 10. Ten years of near daily monitoring of window-killed birds. Here’s a quick 9-year wrap-up:
- 40: average minimum casualties annually
- 360: total casualties (minimum)
- 64: species confirmed as fatalities
- 10: average number of days for birds to be removed/scavenged
Top ten (eleven) species most commonly encountered as casualties at this site:
- Lincoln’s Sparrow (45)
- Ruby-throated Hummingbird (29)
- Painted Bunting (24)
- Indigo Bunting (20) *tie* Grasshopper Sparrow (20)
- Mourning Dove (17)
- Clay-colored Sparrow (16)
- Nashville Warbler (14)
- Common Yellowthroat (11) *tie* Mourning Warbler (11) *tie* Song Sparrow (11)
All carcasses remain in place, and I was saddened to discover this new one: a second-year male Painted Bunting at the main north entrance.
As the molt sequences in this species defy my ability to explain in a coherent fashion, suffice it to say that this was a male Painted Bunting born in 2017. He spent his first winter somewhere in Mexico or Central America and returned to the Great Plains to attempt his first breeding season this spring & summer of 2018. Along the way, he molted some feathers, but he had not taken on the dazzling blue and scarlet and citron of an older male, i.e., one more than two years old. He looks to have been beginning that process, however: Check out the blue feathers coming in on the face and crown and the contrast between the green-edged secondaries that have grown in more recently and the dull browns of his primaries that were the set he grew while in the nest last year.
This poor guy was probably on his way to northwestern Mexico where he would take advantage of the monsoon-driven flush of productivity to give him the fuel to finally replace those primaries in August and September. Then he would head down further south to spend the actual winter before coming back here next May.
Alas, he didn’t make it – all because of a stupid window.
I actually discovered it on my 8/20 survey, but this poor little bird on the 20th was already seething with maggots so I’m comfortable calling it an 8/19 casualty. This was a second year male. Check out the feather wear on his primaries. He was headed south to molt and then continue on further south.
Both hummingbird carcasses still in evidence. The whole bird from the southeastern alcove has been decapitated, presumably by the ants.
The tail from the southwestern alcove made things a bit more interesting by being gone. I wasn’t too surprised by that because we had storms roll through overnight that I assumed would have blown that little bit of feathers away. So I started looking around just to see if I could figure out in which crack in the bricks it ended up. I couldn’t find it, but my more intensive searching did turn up these tidbits:
Aha! So it looks like yesterday’s tail was not necessarily from a hummingbird that had been scavenged. It looks more like a lawnmower got it. It also seems to have been a HY male, Ruby-throated Hummingbird.
Hummingbirds have been takin’ it in the shorts of late . . .
But what’s with the fractional hummingbird reference above? Well, “scavenging” and “removal” are not necessarily the same thing. Often I find the remains of a bird that has been scavenged, but there’s enough left behind that I am able to detect that a casualty has occurred. Those remnants – let’s say a pile of flight feathers left behind by a scavenging cat – can last in place for many weeks. Each time I survey for casualties I’m greeted at that spot with the information that a bird died there (or at least somewhere nearby) even though all the edible bits are long gone. We should be clear that scavenging isn’t the important rate to help us better estimate detection of window-killed birds, removal is. It’s only when every piece of that carcass is gone that I’m unable to detect the evidence of a casualty.
We see this played out all the time with hummingbirds. For some reason, the ants seem to get to the hummingbirds more quickly than they get to other birds. (I have some hypotheses about this, e.g., that hummingbirds are more often flying in daylight and might have lain in place longer than the night-flying warbler and sparrow migrants.) The result is that hummingbird carcasses are rarely in pristine shape when I find them, but they are still there.
Check out hummingbird #1 this morning from the southeast alcove. First, look how obvious it is to detect the carcass even from ~20m away. Up close, note that a good bit of her face has already been carted away, one ant-mandible-sized piece at a time.
This next one (or 0.33 of one) from the southwest alcove will put your observational skills to the test:
See it yet?
Oh, that explains it!
In this case, there’s a pre-scavenged hummingbird (likely also AHY-F Ruby-throated) that is represented by its tail only. But it’s still detectable and largely identifiable.
(UPDATE 10 AUGUST 2017: Today I found a head and wing near where I found the tail on Aug. 9. First, this looks much more likely as a HY-M than an AHY-F. Also, literal scavenging seems less likely. I suspect more that the carcass was chopped up by a lawnmower.)
As I’m about to head out for a conference this week, spring and summer monitoring comes to a close. I’ll begin August 2017 the 9th consecutive year of (mostly) daily monitoring for window casualties at the Noble Research Center on the campus of Oklahoma State University in Stillwater, Oklahoma, USA.
It’s been a busy spring.
Beginning Mar 1st, here’s what has turned up at the Noble Research Center.
- Indigo Bunting – 5
- Painted Bunting – 5
- Ruby-throated Hummingbird – 3
- Lincoln’s Sparrow – 2
- Mourning Dove – 2
- Nashville Warbler – 2
- Orange-crowned Warbler – 2
- Baltimore Oriole – 1
- Chipping Sparrow – 1
- Eastern Meadowlark – 1
- House Wren – 1
- Northern Parula – 1
- Tennessee Warbler – 1
- Yellow-billed Cuckoo – 1
That’s 28 individuals of 14 species, and damn, that is disheartening.
On the plus side, my commitment to checking almost every day has put me in position to save a few birds by getting them safely away from the building and taking them someplace secure to rest and recuperate for a bit. I can’t guarantee that all 6 of these survived the ordeal, but they seemed to be in good shape when I last saw them:
- Northern Cardinal
- Common Yellowthroat
- Mourning Dove
- Song Sparrow
- Yellow Warbler
- Carolina Wren
On 22 July, I published the following post with a methodical and detailed explanation of how I determined this window casualty to be an adult female Ruby-throated Hummingbird. On July 23rd, I received a kind message from Sheri Williamson who gently explained where I had erred in my interpretation. Other than the fact that it was 1) a Ruby-throated Hummingbird and 2) dead, I had everything else wrong! Sheri literally wrote the book on hummingbird identification, so I’m delighted to have her input and grateful for the chance to learn from her.
I have now updated this post with Sheri’s interpretation explained in this blue font. Read on, learn, and enjoy. Thank you, Sheri!
In the midst of the hottest part of summer (105 F here today with a 111 heat index), I found this poor little hummingbird in the southeast alcove of the Noble Research Center.
Okay, but what hummingbird? It’s too easy to just assume “Ruby-throated” and move on. There is no obvious rufous coloration on the back or at the base of the tail to suggest one of the Selasphorus hummingbirds, such as Rufous or Broad-tailed. The wingtips not quite reaching the tail tip does suggest Ruby-throated. (Wing chord 46.0 mm on this one.) The next most likely candidate – Black-chinned Hummingbird – has wing tips that reach beyond the tail tip. So I begin with the suggestion that it actually is a Rubythroat, but it’s time to really examine it now. (So far, so good.)
The first thing to do is figure out how old the bird is. (Right here is where I mess up, and it’s all downhill from there.) Is it a hatch-year bird, i.e., one hatched this spring/summer? If not, it’s an adult: “second-year” if I can determine that it hatched in 2016 or the more general “after hatch-year” if I can’t. So, how do we determine age on a hummingbird?
The best way is to examine the bill for “corrugations.” Baby hummingbirds aren’t born with those long, pointy beaks. They start out shorter and kind of pliable, slowly lengthening and stiffening during the first few months of life. (This bird’s bill is 16.5 mm in length.) You can see this, too – although it’s difficult with my aging eyes. If there are corrugations along something like 50–90% the length of the upper mandible (the “ramphotheca” for you Ornithology students out there), then you can be certain it’s an immature hummingbird you’re examining. Adults will show usually 0% or, sometimes up to about 10% of the bill’s length showing those corrugations. What do you think about this bird?
All right, so this bird is an adult, i.e., AHY.
Nope! It’s a hatch-year bird, and that changes everything.
My other clue should have been that there are thin, buffy edges to most of the contour feathers. This is a bird in fresh plumage. An adult female should show much more feather wear at this time of year. Bill corrugations and buffy feather edges? This little sprite started life in a nest in 2017!
All right, so this bird is an immature, i.e., HY. That means it can be pretty easily sexed. (That part is still true, thankfully!) The most obvious feature for the North American Archilochus hummingbirds is the brilliant throat patch or gorget of males. This bird doesn’t have one, although it does have 3 red feathers in the gorget area and heavy throat-spotting all over the gorget:
That red looks ruby to me, too.
Okay, a few red feathers in the throat is not that rare among females. (Actually, Sheri indicated that it is really rare.) An adult male with so little red really would be odd. (True, but the rest of this paragraph is wrong-o.)
This bird looks like it might be an adult female, Ruby-throated Hummingbird. In fact, a second-year female hummingbird would be pretty unusual with that much spotting and red in the gorget. That makes me suspect that this bird was not born in 2016 and we’ve already determined that it’s not from 2017. That would mean that the bird is at least as old as a hatch-year from 2015. In other words, hatch-year is ruled out by the bill and second-year is unlikely by the spotted gorget. Yes, this is an after hatch-year bird, but it’s more specifically an after second-year (ASY) in all likelihood.
Okay, we now know that it’s a hatch-year bird. We also know that it’s got a heavily spotted gorget and already 3 ruby-reflecting feathers. It’s a boy! Yes, I mistook a young boy for a mature woman.
What else have we got?
Okay, the 6th primary feather on Ruby-throated Hummingbird has a weirdly-shaped tip. In males, it looks like a tiny Samurai sword has sliced off the tip, leaving it with a slightly concave shape that sweeps up to a rather dramatic point on the leading edge. (Although I don’t know for sure, I’m assuming that the shape of this one feather on the wing allows the males to make some kind of a mechanical sound for display.) On females – adult females – a shadow of that shape is present, too. It’s a less dramatic sweep to a point, but the 6th primary definitely looks lopped off at its tip, just like this:
According to the information in Peter Pyle’s identification guide, the feather shape on this bird is still a good match for an adult female . . . but it also is a good match for a young male. It’s still a boy.
The tail tips of female and immature Rubythroats of both sexes are just slightly notched or even straight across. Especially on females, the outer tail feathers have broad, white tips. Adult males lack the white tips on their pointed outer tail feathers, and the tail shape ends up looking strongly notched or even slightly forked. Here’s our bird’s tail:
Checks out for female Ruby-throated Hummingbird. (But again, also checks out for an HY male.)
But wait – if this is an adult female Ruby-throated Hummingbird in latter July, then she should have at least attempted to breed over the past couple of months. That means she should show a brood patch, just like this one:
It kinda means that, but again Sheri was a font of great information. To wit, that’s not a brood patch! Evidently, hatch-year birds of both sexes have apteria (portions of skin from which no feathers are growing) on the breast and belly. Experienced hummingbird handlers know this. Me? Not so much.
When I noticed what I thought was a brood patch on this bird, it colored everything else I thought about it. “If it has a brood patch, it can’t be a hatch-year bird.” “If it has a brood patch, it can’t be a male.” “If it has a brood patch, then those wrinkles I see on its bill can’t be the corrugations of a young bird’s bill.” My bias to weighting my opinion so heavily on something I was sure to be true definitely led me down the wrong path. I needed to apply better critical thinking than I did to avoid such a gaffe.
Which means . . .
There you have it: an adult female Ruby-throated Hummingbird. She had a nest and eggs at some point in recent weeks, though I can’t tell if she was successful with it. She had left her territory and might have been engaged in some local dispersal to someplace favorable for molt. She might also have been in the midst of her fall migration and, given our hot weather for the past couple of weeks I wouldn’t blame her. Either way, and whatever else might have transpired in her life as she alternated between winters in the Neotropics and summer in North America, she is another senseless loss to a window pane in our inhospitable human landscape.
None of that is true. Instead . . .
There you have it: a young male Ruby-throated Hummingbird. He was recently out of the nest and was likely on his first foray from his natal territory. Had all gone well for him, he might have ended up in southern Mexico or Guatemala or Panama. Had he survived the winter, he would’ve packed on as much fat as possible and zoomed out over the Gulf of Mexico some evening in the hope of making it back to the US after 18 hours or so on the wing. Then he would have kept going, orienting to an area probably not too far from where he was born, and prepared for a few months of pitched battles against his rivals and aggressive wooing of the ladies.
He didn’t get the chance, however. Like nearly a billion of his feathered comrades in the US each year, he fell victim to a stupid pane of glass while passing through a human-dominated landscape that can be fraught with danger for wild birds. RIP, young lad.
Monday dawned bright but soon turned sombre when I encountered the study’s first meadowlark (61st species; presumably Eastern) at the northeastern alcove. Worse, it was a baby: HY-U. Worse still: it was alive but mortally wounded and suffering greatly. It was having spasms, was unable to hold its head up, panting heavily, and bleeding through its bill, which was bent at the tip from the collision.
This is the reality of the catastrophic but not immediately fatal injuries that millions of birds endure every year. For those of us who dedicate our time to count them, we must be prepared to come face-to-face with some of our favorite creatures sometimes in the throes of a horrible and painful death. Sometimes we are even faced with the decision to intervene and usher in a more swift and merciful death than the one being endured. So that’s how my Monday morning began: euthanasia via thoracic compression of a baby meadowlark enduring unimaginable pain and fear.
The meadowlark did not recover from its window collision today, and I’m not sure I will either.
I was out of town from 21–30 June and no surveys were run during that time. On June 30th, however, I heard from Dawn Brown and Corey Riding that there were three casualties at the southwestern alcove of the Noble Research Center: a badly decayed Northern Parula (adult male), a female Ruby-throated Hummingbird, and a female (with brood patch!) Indigo Bunting. It’s possible that the bunting came in on the 30th, but the others were clearly killed prior to that date. (Photos by Dawn Brown.) This is officially the first Northern Parula found on the project.
It’s mid-June and, like clockwork, I found a lady songbird today who looks to have been involved in some post-breeding dispersal. This one was a Painted Bunting, an ASY-female with a brood patch at the southeastern alcove.
At this weird building that is the Noble Research Center, I don’t find many local birds dead at the glass. There are no feeders, for example. It’s also not a spot that attracts a lot of baby birds. No, here it’s pretty obvious that migrants are the source of the great majority of the 30–40 victims here each year, with big peaks in mortality during October and May. There is another, smaller peak, however.
That third peak is “June”. For some reason, after the collisions of the northbound migrants have died down by the end of May, birds start showing up again in mid-June. These include migrants as well as local breeders like chickadees and titmice. What’s more, it’s common for these individuals to be females that have recently bred, judging from their brood patches.
Apparently, I am capturing at this site evidence of post-breeding dispersal in females. It is not clear if these birds are looking for a new mate and territory or if they are dispersing to some specific place to molt. It is also not clear if this post-breeding dispersal involves successful or unsuccessful breeding attempts. With respect to today’s bird, however, I have to assume the latter.
Painted Buntings do not arrive here until the first week or so of May. With another week or so of finding a partner, territorial jostling, etc., that means they aren’t even beginning to nest until mid-May, i.e., about 4 weeks ago. It’s possible for a pair to have raised a brood in 4 weeks I suppose, but if so it would be odd for a female to skip town with fledglings fresh out of the nest. Thus, it’s more likely that she was dispersing today following a failed breeding attempt.
I received a message of a Carolina Chickadee dead at the southwestern alcove that was found late morning/early afternoon. This one looked like a HY-U bird, and it was at least a 2 on my fat score index. It seemed odd to me that a chickadee would be laying down fat at this time of year – and we’re still having daytime temps in the 80s – but there just seems to be a lot more movement of chickadees than we (or at least, I) had generally realized.
This bird was another victim of a window pane treated with ABC’s bird tape.
Today I found a Red-eyed Vireo in the southwestern alcove and an Indigo Bunting at the main north entrance.
The Indigo Bunting was a second-year male with zero fat and an impressive contrast of old and new feathers. I left him in place for a removal trial. The Red-eyed Vireo, an ASY female with a brood patch and no fat, is the first vireo I’ve ever recovered as a window-kill from the NRC.
This morning, a dead Tufted Titmouse achieved some grim and arbitrary notoriety as the 250th window-killed bird I’ve found at the Noble Research Center since monitoring began on 20 August 2009. She’s right near the entrance to the northwest alcove, and I left her in place to see how long it takes for her to be removed.
Like so many birds I find in June, this was a female (AHY) with a brood patch. This one had a faint stripe of mulberry juice down the front of her breast and little on her beak.
Intrigued by the pattern, I queried my database for June casualties, 2009–2016. Out of 22 window-kills, at least 8 have been females with brood patches (and additional 7 might have been but the data weren’t recorded).
With apologies for the 1) poor and 2) non-existent photos . . .
I found an ASY male Mourning Warbler (fat = 0) at the main north entrance this morning. He was waaaaay better looking than these photos attest, and I bet he was even more handsome in life.
In the northwest alcove lay a female (with well-developed brood patch!) Yellow-billed Cuckoo (no photo). I left the cuckoo in place, as the ants were already doing a number on her.
In scavenging news, the starling from 5/18 was both moved and eaten: I found a remnant pile of its larger feathers about 5m away from the bird’s location. Whatever picked it up had taken it south to the bushes in front of the northern entrance.
Imagine you are holding a deck of cards. Now toss that deck on the floor and look at all 52 of them. Now imagine that each one of those cards represents a different species of bird. There are sparrows, warblers, thrushes, woodpeckers, etc. With the addition of a Tufted Titmouse this morning, there have now been 52 different species of birds killed in window collisions at the Noble Research Center since I started keeping track in 2009.
Of course, this isn’t the first time I’ve featured Tufted Titmouse on this site: On 24 May 2012, I found a Tufted Titmouse at the Kerr-Drummond residence hall immediately to the west of Ag Hall. That was unusual in that it was a female with a brood patch and she had actually lain down fat (I scored her as a 1).
Today’s bird was similar: She was a second-year female with a drying brood patch and fat I would score as a 2.
According to Yogi Berra, “You can observe a lot just by watching.” My watching has just suggested to me that 100% of the Tufted Titmice that have struck windows on this campus have been females in the last week of May with some fat accumulation in the furcular hollow and a brood patch suggestive of having recently produced fledglings. Is this post-breeding dispersal? Wandering to find a mate for a second brood? Wandering after loss of a brood? Dispersal to a molting area? Questions abound, but with my n = 2, it looks like the beginnings of a pattern to me.