Sunday, April 05, 2009

Never Underestimate a Red-tail and More On the Tulsa Red-tailed Hawks

The Ms are a piece of work.
Here is, I think Mom, watching me from the nest.
This went on for some time without a glimmer of any action at all.
I began changing my position on the ground . When I changed she shifted nearly at the same time. Rather like some kind of heat seeking apparatus.
I began to think that I'd come at some kind of long afternoon lull. Everyone has eaten. Mom would be bird napping if I weren't there. Nothing but the whirr of cars zooming back and forth behind me. Besides it was damp, very windy, and the chill was creeping into my bones. I pick up the equipment, pack it away, get into the car, start it, and Whoosh! A hawk comes out of the nest and instead of doing a high flight away, or a treetop scoot, she dives down and stays a few feet from the ground across the field. Prey? No, she never goes to ground but rather heads for the back treeline. She then follows the tree line, but under the branches so her flight height is just where the trunks of the trees split. Never have I seen this exact pattern. The bird is obscured by the nest tree.
Then instead of heading away from me, she seems to be flying back to the tree nest, higher now--perhaps mid point of the nest tree height, perhaps 30 yards to the side of it. I can' t get my camera to focus on her, I try again, put the camera to my eye and---where did she go? I see a glimpse of wings coming in at a totally different angle of approach than before I put my eye to the camera. What is going on? Well, possibly one of those fancy right angle or complete reverse on a dime moves that Red-tails are capable of.

The hawk has to be about half way up the tree! Where is she?

I didn't find the hawk until I uploaded the photos and zoomed in. Look very carefully at the photograph. Start at the nest. See the upright branch that holds it? Follow it down to where it splits. Right branch holds the nest, left branch goes left and splits again. Follow the branch that goes up to the point where it intersects a split branch coming from below. See the red brown wing out spread and the taloned foot reaching for a perch behind the obscuring overlapping branches?

They are tricksy these Red-tails.

I'm clicking away at the whole tree as at that point as I don't know where the bird went. But wait, there is a hawk standing on the rim of the nest looking into the bowl.
I wasn't sure at that point if that was the bird who'd come in from the left or a different bird.
Now I think that the bird from the left, that had perched below the nest, did a short flight to the nest while I wasn't looking.

A little bigger version.
And then the hawk gets in and snuggles down into the nest. Head still up though to keep an eye on evil me.

Upon examination of all the photos, many more than I posted, I believe this bird is the tiercel. His head does not have the variegation of color on the tips of the head feathers that the formel has.
Clever hawks. The female went out of the nest near the ground flew to the tree line, keeping low until she was obscured by the nest tree. The male flying higher came OUT from behind the nest tree flying higher, he has to make the obscuring branches midway up at least if not to the nest itself. He did a straight shot towards me than a right turn into the tree. He had no way without circling to make the altitude necessary to get up to nest height so he improvised it with long broken flight to a hidden perch and then up to the nest.
Of course by this time, I've been watching him, thinking he is the formel who had been on the nest and is coming back, and therefore am completely clueless as to where she got off to, while I was watching him.
It was extremely well done. Duped again. Isn't it fun? We think we're so smart...NEVER UNDERESTIMATE A RED-TAIL!
That phrase, so often repeated at The Bench, in Central Park, which for many years has been the hub of Urban Hawkwatching in New York City, is a staple. I used it again writing of Kay and Jay a few days ago. Ohio hawk expert, John Blakeman picked up on it and here are his thoughts--

Well, I'm going to expropriate that wonderful phrase, and attempt (attempt) to attribute it always to the wonderful people at The Bench in Central Park. The phrase says it all about the magnificent species. Please give them my regards for this so-perfect phrase.

Even I, a self-proclaimed red-tail expert, find myself too often short-changing or underestimating the powers of this raptor. I, too, must continue to Never Underestimate a Red-tail!

Makes my day.

--John Blakeman

Rhode Island's Karen Anne Kolling has come up with what I think is a terrific idea, to further investigate the Tulsa situation--
Am I correct in remembering that there are other hawk nests in Tulsa? (Was that the area the nice maps were posted from maybe last year?) How are those birds doing? That would say something about whether the prey problem is very local, I would think.
Tulsa Sally’s Nest Update for Saturday
Poor Jay is back on the eggs this morning. Poor thing. We will keep watching. Reports from the ground say that they were seen in a tree, doesn't sound like territorial dispute. Could something have happened to through Kay's hormones out of whack? Could she have realized the prey base is too low for her to raise chicks? The questions continue and we are still watching.
Yes, poor Jay. He doesn't understand. He did his best and for some reason Kay isn't acting the way she has in the past with eggs and she has left them uncovered. He takes over, though he too is possibly a bit hungry, and Kay doesn't return for hours if at all.
As to Kay's hormones, I couldn't find anything specific about a birdie form of post egg laying depression comparable to the mammal form found in humans on occasion after a birth, or any research in this area but that doesn't mean that no chance of of an unusual hormonal swing couldn't exist. But I still think that the major cause of Kay calling incessantly to Jay, and then chasing him off the nest (in my opinion to get him to go further away to hunt) was extreme hunger. Kay would likely not have left the nest unless she was near starving.
From Tulsa Hawkwatcher Bob McCargar--
Here's a follow-up, Donna-
I thought you'd enjoy this because I've never seen a better example of a full crop. Even I can tell on this screen shot that Kay has eaten well in her nine hours away from the nest:
Kay looks like she spent the entire 9 hours eating and making up for lost time. There have to be at least a couple of medium sized prey items in there, perhaps pigeons or squirrels? Or maybe Kay flew far and got herself a big bunny. That bulge is up there with the largest distended crops that I've seen proportionally other than gorging juveniles.

The previous one was the day Norman showed up with a crop like that having left Isolde on the nest for many hours without bringing her food. Needless to say Isolde was not amused and made him sit on the nest for quite some time even after she had hunted, eaten, and preened. But she kept a close eye on him from across the street to make sure he stayed put, just in case.

And also from Bob--
In case there is a problem with the photo, here's the Flickr link:

Also, you may have seen this already, but here's a remarkable photo essay of a juvenile hawk in San Francisco:

Along the top of the frame, it's divided into chapters that you can click on. Just amazing photos. I've looked at it over and over.
Thanks Sally for the photo that includes the visible grating that would be similar to that under the nest. I was just trying to get a general idea about how it compares to fire escape nests and how much air might be coming up from around, or even under Kay, if any.

It has always been interesting to me how hungry the sitting moms are when they don't seem to be expending as much energy as they might during non-incubating months of year through activity. Though the brood patch would allow a certain amount of heat, which they would have to maintain--ordinarily insulated by feathers-- to "escape" to keep the eggs warm. Thereby perhaps making the females need more calories just to keep their body temp at the proper level. Particularly in Kay's case as she sat through days and days of inclement weather including being turned into a snow drift. Of course the formels have just created eggs which would drain their physical resources as well.
And so it goes. We observe, we discuss, we hold our breath hoping for the best, we research, and discuss and watch some more. All the while learning, increasing our depth of feeling and empathy for these tremendous members of another nation.
Donegal Browne

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