Senin, 28 September 2009
A Bad Case of Falcon Fever!
Three weeks ago, I was up in the Indigo Hill birding tower with our friend Nina who was visiting from the southwest corner of Ohio. We were chatting as we watched birds zip through the trees, and across the sky. It was not yet peak fall migration, but there was still enough to look at that our conversation kept getting interrupted by birds that required a glance or two before an identification could be placed on them.
As birds appeared and I called them out, Nina would politely ask me about certain details of the birds' field marks. Lucky for me, she was asking questions for which I had accurate, easy answers. This served to make me feel like I was helping a fellow birder along the path to bird identification enlightenment. It was satisfying.
Oh but pride doth come before a fall. And it being fall, I was about to take a serious fall in terms of my bird ID skills and reputation.
A falcon hove into view, pumping hard from over the old Morganstern place, headed south-by-southwest toward us. It was a half-mile away when I spotted it and it looked big and strong. But what caught my eye first was how hard it was pumping its wings. "This could be a merlin" I said to Nina.
The bird tacked a bit east of its path to avoid a clump of tulip trees. This put it against a stark milky-white background of high clouds. "Might be a peregrine!" I said with more excitement, because to my eyes (which were suddenly on fire with Falcon Fever) the bird now looked worthy of consideration as a larger, more powerful falcon. I had shifted my ID hypothesis from merlin to peregrine.
The falcon slowed its pace, flared its wings and tail and began to glide in a circle. As it turned, it showed (or at least I thought I saw) dark wingpits. "NO WAY!!!!" I shouted to Nina. "There's NO WAY this could be a prairie!" Perhaps the most reliable field mark for a prairie falcon is its dark wingpits. This species is seen irregularly at The Wilds, about an hour's drive from our farm. So this species could be possible, but far less likely in southeastern Ohio than a merlin or a peregrine.
At this point I was insane with Falcon Fever. I SO wanted this to be a good bird. Somehow, I remembered to grab my camera and take some photos of the falcon, which by now was much nearer. It was using the heat rising from our ridge top to gain some soaring altitude. snap-snap-snap-snap. I got image after image.
Up and up the falcon went, into the milky overcast. As it rose, it drifted farther south and was soon out of sight, headed toward the West Virginia hills.
At no time did I reach a final conclusion to the bird's identification. It had flown rapidly with strong wingbeats like a merlin. It had looked large when it first started soaring, like a peregrine. It had shown dark wingpits, like a prairie falcon. What the heck WAS this? I knew I'd gotten some images, so we watched it disappear over the ridge to the south of us, and we headed down from the tower to look at the images and sort out this bird's identity.
As soon as I saw one of my later images, with the bird's wings and tail flared for soaring, I had a hunch that I'd been fooled. Fooled? Yes, fooled.
It was a large, immature, female American kestrel.
The strong wing beats? They could have been those of an inexperienced flyer. But it had flown like a merlin, and looked like one when I saw it head on, coming at us.
The dark wingpits? Perhaps a trick of the light, or a symptom of Falcon Fever?
The large apparent size? That came from its age and gender—young raptors are often larger than their parents after leaving the nest. But it also came from the White Sky Effect. This unofficial phenomenon is well known among birders: Any bird seen against a background of bright overcast or white sky can appear much larger than it actually is. I don't know any of the science behind this phenomenon—it could be all bunk for all I know.
But I also know that it's easy to blow a bird identification, even under ideal viewing conditions. It's one of the things that keeps us humble as bird watchers. And it's also one of the things that keeps me coming back for more. Because every so often you actually get a hard bird identification right, and that feels really good.
I am now under doctor's orders to watch first, remember the obvious, and speak only after a moment or two of quiet reflection. It is hoped that this will cure me of Falcon Fever.
I know some of you are saying to yourselves, "Bill, there's nothing in these photos that says ANYthing else, but kestrel." And you'd be right. But you had to be there to catch the fever like I did! It's not the first time I totally blew a call and it surely won't be the last.
Special thanks to Nina of Nature Remains, for not going "Haa-haa!" like Bart on "The Simpsons" when we discovered how utterly wrong I was about this bird. And to Zick, who DID say "Haa-haa!" But only after first trying to convince me that this was just a big, young kestrel. I should have listened.