From: rigg@osnome.che.wisc.edu (Tim Rigg)
Newsgroups: talk.politics.animals
Subject: Re: Self Regulating Populations
Date: 19 Aug 92 16:16:12 GMT
Organization: University of Wisconsin-Madison, Chemical Engineering
In-reply-to: russ@wpg.com's message of 19 Aug 92 02:39:23 GMT

In article <Bt7M1o.8oD@wpg.com> russ@wpg.com (Russell Lawrence) writes:

   From article <RIGG.92Aug18085948@osnome.che.wisc.edu>, by rigg@osnome.che.wisc.edu (Tim Rigg):
   tr> I am a bit confused.  Do you mean to imply that prey animals such as
   tr> deer can completely self-regulate their population?  

   Let's not limit our attention to "prey" animals, Tim.

   Can predators self-regulate their populations?  Or, were you 
   thinking that their populations would also continue to grow and grow 
   and grow ad infinitum?  Would predators require "culling" at some 
   point to prevent their populations from ballooning out of control?

Okay.  Natural ecosystems can and do self regulate.  However, I am not
talking about some ideal place, but rather the current conditions in
America (and elsewhere I suspect).  Northern Wisconsin might be able
to support other natural predators such as wolf packs and coyotes.
However, the rest of the state can not.  

I'll rephase my question:   in areas without any predation (such as
most of America), would deer and other prey animals self regulate?


As for non-prey animals, I haven't read as extensively about them.  I
suspect that they can self-regulate.

   tr> If deer can self regulate their populations without any predation, do
   tr> you have any guesses why the League Against Cruel Sports used culling
   tr> by shooters to maintain deer populations on reserves they controlled?

   Good question.  If it's true that mammalian fertility drops when 
   fat levels fall below a certain point, why do newsreels of 
   Ethiopian women show pictures of emaciated, starving women 
   alongside emaciated, starving children?  The answer is that such 
   women and children live in environments that are environmentally 
   unstable.  Eco-systems that have been ravaged by natural or man-made 
   disasters (earthquake, war, deforestation, etc) as well as 
   eco-systems that depend on the unnatural influx of chemicals 
   (fertilizer, water, etc) are unstable, and it's in such unstable 
   environments that the likelihood of starvation is most prominent
   among all animals...  whether human or non-human.

   Getting back to the deer park that you mentioned previously, 
   would you say that the reserves in question were ecologically
   stable and free from human interference?  Were the deer that lived 
   therein dependent on the resources of the eco-system alone or were 
   their food supplies supplemented with fat-rich animal feeds and/or
   handouts from well-meaning visitors?  

I imagine the reserves were free from human intervention.  But I also
suspect that that there was no predation (by hunters or other natural
predators).  It is the complete lack of predation that is the problem.


I suspect that you are thinking, "well, let just introduce other
predators and do away with this hunting business."  There are several
problems with this.  First and foremost is that many areas can not
support predators large enough to cull deer herds.  Mountain lions,
bears, and wolf packs would have a hard time thriving in most of
Wisconsin.

Another factor is that the deer cares little what predator ends its
life.  I see no difference between the predation of man and that of
other natural predators.

tim
--
    ...  Then they came for me,
	   and by that time there was no one
	     left to speak up for me. (Rev. Martin Niemoller, 1945)
Newsgroups: talk.politics.animals