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Re: archive searching restored and more on "packs"



At 03:42 PM 5/17/99 -0500, Mickey P. Rowe wrote:
>pairs.  As such, Nathan's opportunity cost is irrelevant.  A lion may
>get less meat when hunting in a pack with four individuals than it
>would if it hunted alone, but if it spent much less energy locating,
>pursuing and subduing the animals on which it fed then the *net*
>benefit (the rate of energy gained - the rate of energy expended) may
>be higher for larger group sizes.  Nathan appears to have focused only
>on the rate of energy gained (or in terms of the statistics that he
>actually quoted, probability of a successful attack given that an
>attack occurred),

I know I am a bit late - but if this is really the measure used, it also
misses one important potential benefit of group hunting: increased
efficiency in *locating* potential prey.  That is, a group might be able to
initiate *more* *attacks* than individual lions, due to more eyes
searching.  This statistic eliminates this variable, since it is success
rate *per* *attack*.

To get at the search benefit, one would need rate of attack initiation per
foray, or per day.

Certainly, for herbivores that eat locally abundant but widely scattered
foods, like fruits in tropical forests, this search factor is a major
benefit to group life.  Whether this extends to predators in open
environments, I do not know.

>Bottom line: as Nathan and Matt (and others) have pointed out, it's
>difficult to understand what's going on with pack hunting in extant
>animals.  ...

That, I think, is undeniable.

--------------
May the peace of God be with you.         sarima@ix.netcom.com