From: russ@wpg.com (Russell Lawrence)
Subject: Re: Hunting-Fat-Fertility. Was: Letter to John Robinson
Organization: WP Group
Date: Tue, 28 Jul 1992 17:16:54 GMT

John S. Van Etten:
jve> However, I would say that in general, *today* hunting is only 
jve> allowed in those areas and on those species where populations 
jve> require it. 

Russell Lawrence writes:
rl> Proof?

From article <viking.712304972@vincent1.iastate.edu>, by viking@iastate.edu (Dan Sorenson):
ds> Self-interest.  If it's a game population, the hunters are 
ds> foolish to hunt it to extinction.  If it's not, it usually has 
ds> some sort of relation- ship to game species, and hence the 
ds> ecological-types and the DNR have little reason to advocate 
ds> extermination over existence.  The passenger pigeon will not 
ds> happen today thanks to these people, and to hunters willing to 
ds> spend a season without hunting if necessary.  It's selfishness, 
ds> Russ, that most primal of human reasons.  

Do you have any empirical evidence to support John's allegation
that hunting is only allowed in those areas that require it?  
Your proof-by-rationale isn't very convincing. 

rl> How much do you know about the hormonal mechanisms that control 
rl> mammalian reproductive cycles?  Specifically, what effect does 
rl> adipose tissue have on the onset of estrus?  And, what percentage
rl> of body fat must a female deer have in order to ovulate?   Perhaps
rl> you don't know the precise figures, but I'm sure you'll agree that
rl> they're well-above the starvation point.  This would lead me to 
rl> believe that mammalian populations are self-limiting in stable, 
rl> natural environments, and therefore, it may not be entirely 
rl> accurate to say that non-human mammals would inevitably starve
rl> without human intervention.

ds> I'm a enginerd, not a zoologist or biologist, but I'll take a
ds> stab at this: Let's say a female deer needs 20% body fat to ovulate.
ds> Fine.  Hogs can lose 7% weight in a half hour, from 120lbs to 110lbs,
ds> during a single ride in a truck.  This is due simply to stress.  They
ds> can put that weight back on in a single afternoon.  

Rapid weight fluctuations like the 7% weight loss you've described for 
hogs is the product of water loss, not fat loss, which explains why
it's so easy for them to put the weight back on.   It doesn't take
a farm expert to testify that a hog can _not_ add 7% of its weight in
fat tissue over a period of a few hours.

ds> Humans have a hard time with weight fluxuations like that.  

Not really.  One of the more popular weight-loss scams involves 
an metallic coated jogging suit that causes humans to sweat 
profusely.  The victims of this con game weigh themselves before 
and after donning the suit and erroneously conclude that they've 
lost four pounds of fat.  They can't figure out why the "fat" 
mysteriously returns after they drink two quarts of gatorade.  

ds> Let's assume it's mostly body fat that is being lost and gained.

Why should we make such an assumption?

ds> If ovulation happens at >20% body fat, then it only takes two days 
ds> of poor feed to negate this effect.  ...  [conjectures based on 
ds> false assumptions deleted] 

Are you suggesting that abundant food resources that would allow 
a deer to put on 20% body fat would suddenly disappear over a two 
day period, thanks to "poor feed"?  Let me remind you that it's 
far more difficult for a deer, consuming brush, to add fat that 
it might be for hogs fed on fatty grains. 

ds> ...
ds> So, Russ, how'd I do?

Your theory needs work.

-- 
Russell Lawrence, WP Group, New Orleans (504) 443-5000
russ@wpg.com   uunet!wpg!russ
Newsgroups: talk.politics.animals