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!