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From: julia@slovax.UUCP (Julia Haviland)
Newsgroups: sci.bio
Subject: Re: Why do Lions Leave us Alone?
Message-ID: <514@slovax.UUCP>
Date: Mon, 10-Aug-87 19:06:21 EDT
Article-I.D.: slovax.514
Posted: Mon Aug 10 19:06:21 1987
Date-Received: Wed, 12-Aug-87 01:46:13 EDT
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Organization: R & D Associates., Tacoma, WA
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> Now, to a lion, we humans would be much easier to catch and eat than
> gazelles, etc. Why do they avoid us?
> 
>         - Have they evolved to treat us as dangerous because we are smart
> 	  and carry spears?  (Is a million odd years long enough for
> 	  lions to have developed this trait, even if it makes sense --
> 	  surely it would be more realistic for lions to adopt the
> 	  behavior of only attacking humans when they did not have spears!)
> 
> 	- Have we as a species been around for too short a time to get
> 	  programmed into predators prey lists? (But leopards prey on
> 	  monkeys).
> 
> Exeptions that spring to mind  are polar bears and crocodiles.  I would
> guess that polar bears eat humans because energy is scarce where they
> live, and that crocs do so because they are dumb, and eat anything living.
> Is it true that alligators will not attack humans (in general)?
> 
> Dick Jackson

(Remarks about sharks omitted.)

A "standard" anthropological/ecological argument is that predators have
indeed learned that humans are dangerous and avoid them.  Humans are
dangerous because of fire, weapons, and pack behavior.  In other words,
a human doesn't have to be carrying a spear to be dangerous.  Also,
humans do not behave like the standard prey animal for most predators.
Most predators specialize in some manner and only occasionally take
prey not in their specialty group.  In terms of energy expenditure, it
doesn't pay to chase unfamiliar prey, they might do something
unexpected.  Therefore, individual predators have to learn to take
humans as prey on a usual basis.

Groups of animals can learn quickly that humans are or are not
dangerous.  Animals in National Parks in both US and Africa often
ignore people and do not react to them either a predators or prey.  If
protected animals are hunted, they soon react like unprotected animals
in their reaction to humans.  Man-hunters appear to individually learn
to take humans as prey, occasionally from other members of the same
species.

I don't know whether crocodiles and polar bears actually take humans as
prey to any extent.  In the case of crocodiles, it may be that the
prey-spotting behavior is so generalized that humans fall into the
standard prey category.  Or it may be that crocodiles have learned that
humans are an appropriate prey.  Polar bears, like other bears, have a
"bad disposition" and it may be that most human fatalities are due to
teritorial disputes and less to predation.