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Re: flights of fancy (or "I'm brave, but I'm chicken****")



 From: bob@intelenet.net (Bob Myers)
 > In the end, I don't understand how this strategy works, though.
 > 
 > I can understand lots of offspring to overcome "accidents" of various
 > types, but to "satisfy the predators"?  I don't understand why the
 > predators don't breed proportionately.

In the end they would - *if* the saturation of young continued.
But it doesn't, the overproduction of young is always highly seasonal,
and often only occurs in *some* years (mast reproduction).  Between
times there is not enough food to support a large predator population,
so when the large reproducion pulse happens, there are too few predators
to fully exploit the excess resources - hence saturation.  In the next
predator breeding season they may well produce more offspring, but these
would then promptly starve as the prey levels drop back to normal.

Note, this works for plant too.  Many species of oaks produce massive
crops of acorns every other year, overwhelming the squirrel population,
which has to survive the interim periods.

The limiting factor is food availablility *between* times of over-
production.
 > 
 > Now, herding I can understand, and I can see where numbers might help:
 > the number of opportunities for a predator might not grow linearly
 > with the number of prey animals if they hang out in herds.

Actually, herding may well be more of a *foraging* adaptation than
a predator escape adaptation (though the latter may be involved as
well).

swf@elsegundoca.attgis.com              sarima@netcom.com

The peace of God be with you.