Wednesday, June 17, 2009

What could still go wrong for this hawk family?

Good news so far for the Franklin Institute hawk family as they make the transition away from the nest. All three eyasses are flying strongly and confidently, the parents make food runs for them, and we hawk watchers have a bigger territory to observe than that window ledge on Winter Street!

I asked our Ohio raptor expert, John Blakeman, whether it is a strain on the haggards (adult hawks) to have three eyasses to tend/feed/watch out for rather than the more usual two.

John's reply:

"No, not at all, for this reason. The number of eggs a formel lays is directly related to the amount of food she's able to capture and eat in mid-winter. If finding prey is difficult, she will lay only one or two eggs. Red-tails that hatch three eyasses have an ample amount of food they can capture and consume.


The parent haggards of this nest are ample providers. I never once saw the eyasses go hungry. Life for these parents is really good - lots of rats, mice and pigeons to easily capture; a good, solid nest (thank you, Franklin Institute); and now three eyasses successfully fledging and growing up. Life could not be better for any red-tailed hawks anywhere. Philadelphia, city of brotherly love. Philadelphia, city of hawk success. These are happy, contented hawks. Nothing could be better for them."


I then asked John what could could still go wrong for this hawk family.


John replied, "In honesty, because they are wild animals, just a lot of things could go wrong. It’s tough out there, and only a small fraction of hawks that fledge ever survive to adulthood, in two or three years.

All three of this year’s eyasses may perish before becoming adults. They can be hit by a car, even on the Parkway, as a bird shoots across the road closing in on a mouse in the grass. Young red-tails sometimes crash into wires, fences, or poles and break a wing, or otherwise become disabled. Lastly, they could become infected with several lethal diseases, including aspergillosis - a fungus in the lungs (sadly, my eight year old falconry red-tail died of this last winter), frounce - a protozoan infection of the mouth and lungs, or just plain starvation.

At least for a few more weeks, probably until mid-summer, the parents will provide food. But when the days begin to markedly shorten in late summer and fall, the parents close the pantry door. The eyasses must by then have learned to hunt and kill on their own. A few birds fail in these endeavors and starve to death. Again, as wonderfully nice as all of what we saw seemed to be, each of these birds, especially the eyasses, are always close to a rapid or unforeseen demise. No animal in nature lives with any special security. Injury, disease, and death are always near at hand.

I mention all of this so that if anything untoward might happen, it could be understood as a part of the larger natural scheme of things. Have any of us pondered the pain that was suffered by the rats, mice, and pigeons that our birds so brutally killed? From a mother mouse’s perspective, to be inappropriately anthropomorphic, our hawks are brutal and uncaring killers."

- John Blakeman

3 comments:

  1. Well done, John. Think that this group's intimate exposure to three months of
    nesting, parenting and the development of the nestlings into eyasses
    has provided us with better appreciation for the needs of wild animals
    at the top of their respective food chain. That doesn't mean our hearts
    don't wander into the nests of their prey, only that our minds are
    now filled with indelible memories to rationalize what it takes to perpetuate our beloved redtais.

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  2. I do feel sorry, in a way, for the animals that end up on the hawks'lunch table. On the other hand, the hawks do those species a favor by keeping overpopulation down. There's not a lot in the city to keep the populations of rodents and birds in check. In the case of pigeons and rats, overpopulation can cause problems for humans as well as for their own species. And they are programmed to breed as though they will have an attrition rate due to predation... only in the city, predators aren't necessarily common.

    Disease and starvation, two of the side effects of overpopulation, are a crueler ending for those prey animals compared to a quick end dealt by the hawks' talons. So as unfortunate as it might be to the individual animal to be taken by a hawk, its species will benefit from having hawks take out the sick and weak ones.

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