From: viking@iastate.edu (Dan Sorenson)
Subject: Re: Self Regulating Populations
Organization: Iowa State University, Ames IA
Date: Mon, 7 Sep 1992 18:19:01 GMT

In <Bu4A51.9F6@wpg.com> russ@wpg.com (Russell Lawrence) writes:

> viking@iastate.edu (Dan Sorenson):
>ds> One point you seem to be overlooking: deer are fairly low
>ds> on the food chain.  Such status would make size less important than
>ds> unfamiliarity when regarding the potential threat of another animal.
>ds> Evolution as a prey animal favors wariness over size discrimination.

>I've noticed that you often derive your "facts" from theories, 
>instead of basing your theories on facts.  Bad habit, Dan.  :-) 

	What theory?  It's a fact that animals low on the food chain yet
much larger than I are afraid of me in most cases.  Likewise, the Cape
Buffalo doesn'tignore the lion or tiger just because it's only a fifth
as large.  The difference between "theory" and "fact" here seems to be
dependent solely on not seeing it in a journal of some type.

>I've been kicked by a horse, and I've been kicked by birds.  The 
>horse kick landed me in the hospital with three broken ribs, 
>whereas the bird kicks were inconsequential.  The kick that broke 
>my ribs would have killed a wolf, and could have killed me if 
>medical care had been unavailable.  

	I've been kicked and trampled by cattle, too, yet none of my
injuries required medical attention.  The wolf, however, may or may
not have required some.  This depends on many factors.  In any event,
it appears that the defensive weapon of the horse that kicked you were
its hooves.  Note that those hooves are also quite good at providing
speed, another defensive weapon that horses would be more likely to
use against another animal they consider a threat.  Can you otherwise
explain why prey animals tend to have superior sensory abilities and
are posessed of great abilities in the running department?  This is not
true in all cases, but in general the formula is (weapons x speed) = K,
where K is a constant.  Speed is useless if the attack happens before
you sense the predator.  Thus, it's easily derived that sensory
perception is a trait that favors survival, and through centuries this
trait would be firmly embedded in the animal.  It would also show up
in the predators, simply because not finding prey is a genetic dead end.

>ds> However, the fact remains that deer have quite good eyesight, excellent
>ds> hearing, and a refined sense of smell.  Coupled together, they make for
>ds> a formidable sensory array that I cannot hope to match without tools
>ds> such as telescopic sights, buck scent, and camoflauge clothing.

>Do you have any evidence to support the claim that the eyesight of
>a deer is "quite good", as you say?  Or, is this another one of those
>assumptive "facts"?

>ds> 	As for what makes me think deer can witness this, I've seen deer
>ds> bolt at a mile distance (two sections of field) when I stepped from the
>ds> tractor to <ahem> answer the call of nature.  The tractor they let within
>ds> about forty feet, but they ran back into the woods at a mile range.  It
>ds> is possible they did not know what I was...

>Precisely.

	You'll notice they didn't bother to stick around and determine
precisely what I am, either.  This not only proves that flight is a far more
often-used response than fighting among the prey species, but that it is
not necessary to have a detailed view of an unknown before concluding that
it might be a threat and is worth avoiding.  You make my point for me, Russ,
with regards to the wariness of prey species with regard to unknowns.

>ds> What's your reaction when you hear a siren?  You look around
>ds> for possible danger, even before you know what the police are, let
>ds> alone what the siren is supposed to communicate...

>What's your point?

	The point (you're being deliberately dense here, aren't you?) is
that there is no need for precise verbal communication when conveying a
simple message such as, "Get outta the way!" or "Danger, Will Robinson!"
A gunshot will alert any animal, even if they have never heard one before.
So will a siren.  Any loud, unusual noise is sufficient to cause a being
with hearing to look around for the source of the noise and any possible
dangers that noise might mean.  That the animal has never been trained or
informed of what that sound means does not matter, as its default reaction
is precisely what is needed for the situation.  In short, on alert.  When
that sound becomes familiar, the default reaction is changed, so that
thunder won't cause alarm while a gunshot (different sound) will.

>rl> How far can deer see clearly, Dan?   

>ds> At one mile they can see clearly enough to note me leaving the
>ds> tractor cab...

>Does the term "post hoc ergo propter hoc" mean anything to you?   Please
>furnish some evidence to support the claim that deer can distinguish
>human movements at a distance of one mile.

	"post hoc ergo propter hoc?"  Isn't that roughly translated as,
"happened once, therefore happens all the time" or something like that?
A translation would be appreciated, since I don't figure Latin is a
language worth my time to study.  Come to think of it, there are no other
languages worth my time to study -- English proficiency is a lifetime-
long work as it is.  Anyway, the evidence has been shown already, and
can be supplimented by any hunter who sees a deer bolt and turn at one
mile into the wind.  I suspect your requirement of "clearly" is the catch
to this, but it's irrellevant so long as the sight can be clear enough to
show *anything* that might be a threat.  What constitutes a threat is an
exercise for the potential prey and will vary among individuals.

>ds> "You bet.  I'm a damn good shot.  Take maybe forty or fifty 
>ds> carribou a month to feed the dogs," as the eskimo said to Farley, 
>ds> if I remember right.  Farley then comes to the realization that 
>ds> the eskimo kills several times as many carribou as the wolves do.  
>ds> Yeah, I read that book nearly ten years ago.  It was good, but 
>ds> hardly a scientific treatise on predator-prey relationships.  

>One of us has a poor memory.  Please quote the passage where Farley
>came to the conclusion that the eskimo killed "several times" more
>caribou than the wolves.  

	Loan me a copy of the book.  Like I said, it's been nearly a
decade since I read that book, and I may have been inaccurrate in the
quote.  However, I think that Mowat did come to this conclusion by
taking into account the number of eskimo and the number of wolves and
factoring the meat requirements of each.  It takes a lot of meat to
feed those sled dogs, who probably out-number the wolves, and the
eskimo tend to keep the sled dogs well fed.  Since you seem to have
the book handy, would you mind telling us what the passage says?
Perhaps then I could see what you mean to imply about predator-prey
relationships.  I suspect it's a simple concept that is being obscured
in the writings of us both.

>I agree that this book isn't a scientific treatise on predator-prey
>relationships, but it's quite a bit more factual than the assumptions,
>derived from your theory, that you've presented to support your theory.

	I disagree.  Mowat is more qualified, but is writing on the basis
of experience.  I am writing on the basis of experience.  If I wished to
become all-knowledgable on this subject I'd change my major and study it
more thoroughly.  Since I wish to make serious amounts of money in the near
future, this is not a course of action.  Still, the fact that something has
happened cannot be disputed, and the lessons drawn from that event may be
applied to the existing base of knowledge.  If deer can spot me at a mile,
it is clear that they can see that far.  It is not clear that they can
determine if I'm armed, male, or even what my size is, but it is clear
that they determined I was enough of a threat to warrant leaving the area.
The hulking shape of a 4440 John Deer, coupled with the growl of the diesel
motor, did not produce such a response.  Thus, it appears that they did not
see the tractor as a threat (quite probably due to familiarity), but did
see me as a threat.  What is being assummed here that is not clearly stated
as an assumption, and what is fact?  The "facts" you might see in any journal
on animal behavior are built upon such evidence as I have provided, and
we both know the outdoors is not a lab setting where we can remove all but
the factors we wish to evaluate.

<Dan Sorenson, DoD #1066 |"There'll be angels on Ariels in leather>
<z1dan@exnet.iastate.edu | and chrome, Ridin' down from heaven    >
<viking@iastate.edu      | just to carry me home." -- R. Thompson >
< ISU thinks I need more education, which they provide for a fee. >


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