I was in Colorado for a conference last week, and grateful that in my absence the Loss Lab’s Corey Riding and his band of merry building-checking undergraduates covered for me at the Noble Research Center. On 26 September, technician Cooper Sherrill found a Carolina Chickadee at the southeast alcove and a Common Yellowthroat at the northwestern alcove.
This morning, I found a Wilson’s Warbler at the north entrance. This example illustrates well the difficulty in ascribing a bird as a casualty or as merely “trapped”. In this case, it is clear that the bird was stunned from an apparent collision as opposed to merely exhausted from repeatedly trying to fly through what looks like an open passage. Check out its tightly shut eyes until I was right up next to him.
I had almost got my hand on him when the bird flew to the back of my left pant leg (where he stayed for a second or two), before he flew (a bit wobbly, but airborne nonetheless) to the “Recuperation Tree” where so many birds stunned by collisions with the NRC spend some time. Despite his obvious closed-eyed distress, he flew and perched strongly in the tree, so I count him as trapped and survived rather than as a casualty. He’s not out of the woods yet, however, and he’d certainly be an easy meal for even a clumsy and inexperienced predator.
This is the indirect cost of building collisions. So far in 2014 I’ve documented 26 birds killed at the Noble Research Center, but I’ve had 11 trapped birds as well. Of those 11, surely some would have survived the experience without my intervention, but how many? What is their prognosis after escaping the the NRC? For many of these birds with whom I have the ability to interact for a few moments, I can tell that they are not nearly 100% just because they’re too fast for me to catch or can sort of perch normally.
No sign of the suspected MacGillivray’s Warbler either . . .
Today I found at least one, and very likely two, new species for the study. In any other study this would be cause for celebration. Not so, here.
First, I encountered a trapped bird at the north main entrance. I could tell immediately that it was an Oporornis – now Geothylpis – warbler, and Mourning is the most likely candidate by far. This bird was sprightly and flew strongly as I attempted to steer it away from the NRC. I was unsuccessful as it perched in the trees near the entrance, but at least from that location the bird would be more likely to detect the barrier that the building presents and less likely to build up sufficient speed to do any lasting damage. I ruled it a “trapped” bird for that reason, and I really hope that it’s gone by tomorrow . . .
I couldn’t get close enough to catch it, but it was perched in rather open spots on the ground and in the trees so I fired off some photos. My examination of the photos led me to believe that this bird was actually a pretty darn rare one this far east: MacGillivray’s Warbler. It looks to me to be a AHY female, judging from the whitish throat and the two, broad eye arcs above and below the eyes. I have shared the photos with our state birds record committee coordinator. Until I hear definitively from him, I’m reserving final ID on the bird. I do think it’s MacGillivrays. What do you think?
The eBird distribution above illustrates how unusual an occurrence a MacGillivray’s would be this far east. It’s certainly the first one I’ve seen in Oklahoma, and I think the only one I’ve ever seen east of Las Vegas.
Next, I found a dead bird at the south entrance, and this was the penultimate pinnacle of avian evolution, the Northern Waterthrush. It was an AHY bird with fat = 2, and in truly gorgeous shape before meeting its untimely demise. This is the 50th species I’ve found dead at the NRC, and the 186th casualty.
Carolina Chickadee feather pile officially no longer in evidence.
Our first decent cold front of the summer came through last night just as the sun was going down, and this one brought some actual rain. Thus, by about 9:00 pm, conditions were ripe for a major fallout of migrants as the ceiling lowered and the rain and storms moved in. At time of writing, we’ve now had about 13 hours of steady rain. From Paul Hurtado’s radar ornithology page, these images show the impressive flight underway last night and the rain slicing through central Oklahoma that was forcing birds down.
While that rain was starting up last night, I heard an Upland Sandpiper and multiple Dickcissels passing over. This morning at dawn, Common Nighthawks were flying around my neighborhood, and the Dickcissel flight calls were incessant.
By about 9:00 am, I had walked into campus (about a mile from my house) and already found a road-killed Sora. At the NRC, there were numerous Chimney Swifts flying about, and the usual European Starlings and Great-tailed Grackles. I also found two Mourning Warblers not quite trapped at the main north entrance to the NRC, and some other warblers moving through the trees. The steady rain and my lack of binocs made positive ID difficult.
Sadly, I had no problem identifying the two casualties I found at the building today: both male Wilson’s Warblers and both in excellent condition for migration, bulging with fat in the furcular hollow and on the belly (fat = 3). One (the HY male – just a few months old) was at the southeast alcove and one (the AHY male – at least 13 or 14 months old) at the southwest.
The little dears were pretty waterlogged, so they spent some time in front of my space heater this morning.
Sometimes this work can be rather surreal. This morning, while working with Scott Loss on training a group of undergraduate students in monitoring buildings for window kills, the students were looking in exactly the right direction to watch a young cardinal fly into a window about 10m away. The bird, a HY male, lay on his back stunned for a minute or two, then it perked up and flew strongly before perching in a Japanese maple very near to us. He was groggy, but I’ll assume that he’ll recover in the absence of evidence to the contrary and record him as “stunned”.
I found this AHY, fat = 2, female Mourning Warbler at the southwest alcove this morning. My warm memories of these birds are of finding them skulking through the ferns in Pennsylvania’s Allegheny National Forest, with the males’ ringing and rolling song sharing airspace with the Winter Wrens’. Dead at a window in a landscape of steel, glass, and concrete is an ill-fitting end to what must have been an exciting, adventurous life for this little gem.
Chickadee feathers remain . . .
I found this Carolina Chickadee at the North Entrance to the NRC today, and it was pretty severely mangled by the ants and at least one large beetle. I don’t know if I missed this bird from a day or two ago (unlikely given it’s conspicuous location), of if these insects have just been able to tear into it with ferocious rapidity.