Wednesday, April 21, 2010

Why the hawk brought leaves instead of food to the nest

Yesterday, when the food service to the nest was still getting up to speed, we noticed greenery arriving instead of a mouse or pigeon. Was the greenery some kind of camouflage for the baby eyasses?

John Blakeman gives us this fascinating insight into the mindsets of the parent hawks:

"No, the leaves brought to the nest were not intended as camouflage. Clearly, they didn't obscure our view of the tiny eyasses, and neither would they have done that for any passing nest raider, such as a crow.

But we shouldn't presume that the eyasses were unprotected in the parents' absence. Very much the opposite. Although the formel stepped away for an interval, be assured that she was in full view of the nest and had her eyes on all activity in the nest region. Had a crow or any other bird started to fly anywhere near the nest, she would have responded instantly and powerfully.

And the tiercel, too, during his long, all-afternoon absence, was almost surely in direct eye contact with the nest, or at least the general nest territory, where he could quickly go in and push away any intruders. We are getting to watch but a square meter of the nest surface, while both of the haggards are surveying the entire airspace of this part of Philadelphia.

As I watched the formel sitting on the nest yesterday, eagerly awaiting some food (for her eyasses, not for her -- she can easily and comfortably go two or three days without food), I noticed her visual attentiveness. As a falconer who has watched my red-tails hunt right from my fist, I'm aware of the hawk's slight nuances of increased interest in the landscape in front of her. The formel was keenly aware of and watching everything around her nest yesterday.

Why did the tiercel bring some leaves, instead of some food, to the nest? Doesn't make sense, does it? But in fact, these birds are not acting on "good sense" or rational thinking in any human manner. Their brains don't work that way. They can't. The hawk brain is rather small, and utterly incapable of the deliberate (but simple) thoughts that went through our heads yesterday as we anxiously awaited food all afternoon for the now-hungry (but still safe) little eyasses.

Red-tails are mostly eye ball, not brain. Their eyes are almost as big as a human eye, taking up at least two-thirds of the cranial space. The brain is only a small organ at the back of the head. The rest of it is a pair of powerful telescopic eyes. Consequently, the behaviors of the hawks are almost always -- with one exception I'll mention -- very "ritualistic." They almost clumsily "go through the motions" to do things like feeding the eyasses.

When you watch the formel feed the eyasses, she always gets the job done, but in fits and starts and awkward and inconsistent motions. Let's face it. She's a bird brain. She (and her tiercel) can't think very clearly and can't act very deliberately. They ritualistically go through the motions when incubating, rolling the eggs, and feeding and protecting the eyasses.

That's why the leaves were brought to the nest. It was "something do do." In human terms (more so than I, as a male would like to admit), the tiercel, meagerly, was thinking, "Hey, the formel's really got something going there on the nest. I'd better DO something. Now just what can I do? Hey, I'll bring her a beak-full of leaves. She liked that a month ago. That oughta do it!"

We males are, by and large, mentally disadvantaged in figuring out the feminine mind and its enigmatic perspectives. It's the same with the tiercel. He's still scratching his head trying to figure out what to do now. "Oh, I'd better bring a bunch of food over to the nest, I think."

But there is one area of thinking where the red-tail and all hawks excel. Here, I'll mention it only briefly. It should be a chapter or two in my book on red-tails that I will be writing.

Red-tails are simply brilliant hunters, spending hours each day observing prey and calculating how to efficiently and successfully capture, kill and retrieve food. Nothing haphazard or random or ritualistic with this. It is with great cunning the tiercel has learned to capture energy-dense city pigeons, birds that could easily and otherwise escape a slower, bulky red-tailed hawk.

And that's why I so much would like to see postings on exactly how urban red-tails capture pigeons. Clearly, they do it with calculated cunning and directed ambush. Smart birds, them -- in this unique regard."

--John Blakeman

10 comments:

  1. Even though this has been going on for millions of years...it is fascinating to watch...how they do all this....a nest, perfectly shaped like a safe little bowl..etc...and all without the all important opposable thumb.
    Love Blakeman's information. I will be buying the book:)

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  2. There's 3 babies!!!!!!!

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  3. Greenery from what plant? Could it be one that has insecticide properties? Birds are known to use such thing to reduce the numbers of parasites in the nest.

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  4. The greenery seems to come from trees in the immediate neighborhood - white pine in teh winter, and maple and London plane trees now.

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  5. I don't know if Mr. Blakeman reads these comments, but if he does, I have some questions. I live in So. Cal. 2 red-tails returned to a nest high up in a pine tree in my backyard for the 2nd year. Last year the whole neighborhood had the privilege and joy to witness the activities from birth of the eyasses until their 1st flights. We had people coming from all over and took many pictures. Tragedy struck last Friday because we found a dead red-tail in my neighbor's yard face down--no trauma. We suspect he/she ate a rat who had been poisoned. On Sunday, I saw one hawk at the nest who seemed to be in distress and having problems flying. I'm assuming this was the mate of the one that died. But then yesterday I saw a hawk again in the nest looking fine and I could see something white in the nest. Will the mate raise the eyasses by itself? If there are no eyasses -- just eggs--will the nest be abandoned? What, if anything, can I do to help ? I feel horrible about this because this is not an act of mother nature--it's a human being not thinking when they put rat poison out. Mr. Blakeman, I would really like to be in contact with you because I have so many questions. Please email me at gloathome@cox.net. or post something that would at least answer my questions above. Thank you so much.

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  6. I just posted the above comment and now just realized that my email address had a period at the end which is incorrect. My email address is gloathome@cox.net

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  7. I'll email with my comments.

    --John Blakeman

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  8. I would love for you to share your insights on the above scenario. Tough, tough situation...

    Gene

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  9. That's the tough part about watching a wild animal's life. Having to witness and tragedy and probably just nature take its course. Even though this bird probably died because of unnatural poisons. Even then..should nature just take its course in this situation. It's not just mending and sending back out. It's help raise these babies for weeks. Don't take the babies away either. Hope we can hear the "solution."

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  10. Rat and gopher poisons kill untold numbers of non-target animals every year! Even using rat poison in the house can cause death to local beneficial predators (owls, hawks, foxes, coyotes, bobcats, etc.) because it takes several days for the rat to die, it often goes in search of water. In its weakened state it is an attractive prey item to a predator. Just ONE posioned rat fed to a nest of raptor chicks can wipe out the entire nest. Please don't ever use poisons (or glue traps: non-toxic unless you are the poor creature who gets stuck on it and dies a slow horrible death).

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