Monday, April 18, 2005

Blakeman on the Kestrel's Demise

I sent Steve Watson's letter about the demise of his nesting male kestrel Dash to John Blakeman, just as Steve had suggested I do. Below is his realistic, not unexpected response. Then after that I am including Steve's letter I received last night. He had read Blakeman's response. He too, as you will see, is realistic. But Hope is the thing with feathers.

The loss of the Pasadena kestrel tiercel is unfortunate, albeit by a natural element, another avian predator, a hawk even.. The death of the little falcon is gruesome enough, but things are not likely to go well for the surviving mate and the developing eggs the pair was incubating. It is highly unlikely that the female will be able both hunt to feed herself and also remain on the eggs to keep them warm enough to stay alive. The only hope is that a large, easily accessible prey population (such as numerous grasshoppers or mice) is right outside the nestbox. Given that this is on institutional grounds, I doubt that the female will be able poke her head out of the nestbox, find a food animal to capture, quickly drop down on it, consume the prey, and then promptly resume her requisite incubation duties. The poor female has too many required tasks to accomplish. Without the supporting male, things don't augur well for the kestrel family.
And even if the eggs were to hatch right away, the single falcon would be hard-pressed to find sufficient food to raise the eyasses.
Almost surely the incubating female will be driven by hunger to leave incubation and head out for food. Her chances of consistently finding, capturing, and consuming it in 10- to 20 minutes, time after time, probably three or four times a day until the eggs hatch, and additionally until the eyasses are 6 to 10 days old, when they can stay warm by themselves, are very bad.
All of us need to confront the cold, natural reality that what happens to the prey of our beloved red-tails and kestrels also happens, from time to time, with our hawks as well. Unlike the plot of a novel or movie, we don't get to presume that nature's story will always turn out as we prefer. Accept the fact that nature is it not always as we wish it. Nature (to personify it -- an error) has no concerns about individuals, only populations. The kestrel population of Southern California is probably fine. Our observed family is now in disarray, with the eggs soon to die, leaving the mother a widow and alone. Cruel and disheartening, but coldly authentic.
If the mother kestrel escapes any future attacks of the sharp-shinned hawk and survives (very likely), she will retreat to a normal day to day life of personal hunting, to eat and survive. It's almost surely too late for her to find another male who could copulate and sire young this late in the season. A reproductive year has been lost. Things will have to resume next year, with a new male.
This isn't the first time this has happened. Things will work out, but again, only from the perspective of an entire kestrel population. This pair is no more. The remaining female could be killed, or she could survive, mate with an new male next year, copulate, and bring off a new brood of four kestrel eyasses. But that's next year's story. For now, we can only contemplate.
I recommend that the nest box not be cleaned out. Remove only the dead eggs. Leave the lining material in there Kestrels prefer older, settled lining material. Next November, you might want to take a peek inside and see that enough wood chips, excelsior, or other material remains. Merely add enough to make up the difference of what was compressed or lost. Don't take it all out. Do that in the second or third year after young have grown up in there, cleaning out the mutes and old food debris. Sadly, there won't be any of that this year.
Does everyone understand that life in nature is cold, cruel, harsh, even unforgiving for all? This episode authenticates it. Be careful about inappropriate, even romantic explanations for what has occurred. It's real nature, not always as we'd like.
I thank Steve for arranging for the camera. Do it again next year, when we might be able to see a kestrel family being raised.

John A. Blakeman