Wednesday, January 19, 2005

BLAKEMAN on TALONS

BLAKEMAN on TALONS -- 1/19/05


photo by Lincoln Karim

John Blakeman, the extraordinary Ohio falconer and hawk expert whose letters are enjoyed by so many readers on this website, saw Lincoln's photo of talons on PaleMale.com and sent me the following comment:

Marie,

I saw the wonderful close-up of one of the hawk's feet on the PaleMale.com site on Tuesday evening. I noticed something rather interesting.

First, this is a remarkable photo. Wonderful work.

But I instantly noticed the rounded dullness of talons on the left foot. They are seen in perfect profile in the image, and they are markedly dull. Typically, red-tail talons are needle sharp, instantly able to pierce the skin of any prey they encounter – and for squirrels in particular, this is very important. Squirrels have particularly thick skin that can resist the 40-60 lbs (or greater) of force of a redtail's grip. (Although the squirrels of Central Park are apparently gray squirrels, a slightly smaller species than the thick-skinned fox squirrels of my area.)

Obviously, this talon dullness is of no real concern. The birds are eating well in Central Park. But it does reveal that they are spending a lot of time landing, perching, and taking flight from stone ledges on buildings. This is dulling the talons. Birds that spend their lives in trees have needle sharp talons. The rubbing of the talons on the bark of tree branches appears to sharpen them. But when rubbed along stone ledges (buildings in NYC), the sharp ends can get dulled, as we see here.

Again, no problem. Pigeons have very thin skin and are easily dispatched. Squirrels may require a bit of experienced foot and talon manipulation on the head, followed by a lethal bite. Rats are easily dispatched with a quick grasp of the head.

But a close look at the talon end shows a flattened end. Curious.

Oh, and the extended right foot? That's merely a stretch. Falconers see this all the time in their confidently-perched birds. They pick up the loose foot, squeeze the talons a bit, and extend the leg outward, as seen here. Just after the picture was taken, the bird brings the foot back under its belly and perches on a single leg. Later, it will reverse to sitting on the opposite leg.

When I trap red-tails for banding, I always examine the toes and feet for remnant blood, feathers, or fur, revealing a recent meal. I couldn't see any leavings here.

(We can't get photos like this out in the countryside. Nice work.)

Sincerely,

John A. Blakeman


A SMALL CORRECTION - 1/19/05

John Blakeman's comments on how to tell the age of young hawks by eye color appears lower on this page. He has sent in a small correction, and has added to it a some interesting observations about red-tailed hawks and their appetites:

I should have been a bit more careful in the RT aging notes I submitted. I took the info off the top of my head, not from my written records of accuracy. I made a slight goof, stating that in third year RTs there is a remnant hint of yellow at the bottom of the eye. Wrong. It's at the top of the iris. I just went out to feed my three-year old red-tail, and saw my error in hand. (This is why scientific papers are peer-reviewed before publication.) It's a minor point, but an error, nonetheless.

If I can, let me make a one other observations that Central Park hawk watchers might find interesting. Lincoln mentioned that the young bird he saw (surely one hatched in 2004, as it had a brown tail), was spending some time peering at a rat that could be seen at the base of some phragmites (common reed, a horrible nonnative wetlands invader from Eurasia – sorry to hear that Central Park has it, as we are trying to suppress it before it completely overtakes the last open Lake Erie marshes in my area). From the tone of Lincoln's note, he seemed to wonder why the hawk failed to drop down on the rat and have an easy lunch. He noted that the hawk later flew off toward some mallard ducks on a pond, but the effort seemed only modest to Lincoln.

He was correct. The hawk's flight at the ducks was certainly only halfhearted and inconclusive. Lincoln has surely seen enough RT hunting flights to discern which ones are serious, fill-the-crop ones, and which are token “let's see if they fly” ones. This flight was the latter.

Here's what I make of both of these observations. First, the reluctance to drop down on the quite vulnerable rat: Any RT that passes up so convenient a meal as this does so for only one reason. The bird simply was not hungry. It has had a full-crop meal in the last day or so, and also has ample fat reserves. This bird is living well, so well, in fact, that it can afford to be selective in what it wants to attack for food. The bird may have had Rattus norvegicus flesh for the last five days, and now wants to savor some other Central Park morsel. After all, as good as NY restaurants are, who chooses to order exactly the same meal each evening. The hawk was merely pondering the menu, and Norway rats didn't excite her palate. Being previously well fed, she could afford some culinary discretion, even if it meant passing up an otherwise easy meal.

We falconers recognize this behavior well. Our birds, when hunting, are as free as the hawk Lincoln saw, and they will only hunt when hunger prompts, exactly as wild birds do. That's why falconers carefully weigh their birds before hunting. The hawk must be high in muscular weight, but not fat; just like a trained athlete. A hawk too fat just sits there and contemplates the landscape. When that happens, it's time for the falconer to offer the hawk a choice tidbit of meat on the fist and call the bird back to hand. Wait a day, and it will then resume its natural hunting desires. Lincoln's bird was both fat and sassy. It will be a survivor. (Sixty to eighty percent of all first-year RTs fail to survive the year. This one will survive and probably go on to breed.)

About the pass at the ducks. This bird is in its adolescence. And like most adolescents (well, except for you and me, who were perfectly behaved), this hawk couldn't resist the final urge to take a pass at these big -- well -- sitting ducks. But the hawk didn't have a chance of capturing one of these fleet-winged wonders. An RT in a straight tail chase (right from behind, not from high above) can barely hit 40 mph. A mallard can accelerate quickly to 50 or 60 mph. Our teenaged red-tail didn't have a chance. But it sure was exciting to make those water-soaked birds get up and fly away. (And which one of us wouldn't do that from time to time, too, if we could be a red-tail for a day? Raise a little hell, just to see what happens.)

All of what Lincoln saw in this passive red-tail has led many to believe that the species is slow, dumb, even phlegmatic. The big oafs just spend a lot of time sitting around and get characterized as lazy. But that's a complete misread of the species. When hungry and highly motivated, an RT can take almost anything. When hungry, it can take a mallard, but will do it by clever ambush or aerial stealth, just as pigeons are taken by Central Park RTs. Let it be understood by all, our red-tails are extremely successful hunters. They are intellectual, cerebral hunters weighing a multitude of factors that give them the best probabilities of hunting success. Nothing is random or by chance.

Some have thought they'd like to go to the last wild areas of Africa and watch the great cats hunt antelope or other prey. Few of us will have that opportunity. But exactly the same predator/prey interactions can now be seen in Central Park, of all places. A moderate understanding of the behaviors of the CP red-tails can illuminate what's transpiring. These birds aren't just sitting there, and they aren't just flying around randomly. They are living their remarkable lives as their biology dictates. Presently, we get to see it, understand it, even share it. And we don't have to go to the Serengeti to experience nature so raw in tooth and nail (or talon and bill). Of all places, it's in Central Park.