From: robinson@ac.dal.ca
Newsgroups: talk.politics.animals
Subject: Re: New Subscriber and a look on hunting
Date: 6 Apr 92 15:38:53 GMT
Organization: Dalhousie University, Halifax, Nova Scotia, Canada

In article <h=wtryf@rpi.edu>, schwae@marcus.its.rpi.edu (Eric A. Schwartz) writes:
> In article <1992Mar31.164400.4679@ac.dal.ca> robinson@ac.dal.ca writes:
>>In article <p9qtz8_@rpi.edu>, schwae@marcus.its.rpi.edu (Eric A. Schwartz) writes:
>>> In article <1992Mar26.101119.4553@ac.dal.ca> robinson@ac.dal.ca writes:
>>>>
>>>>  Hint #3: It is a well known fact among hunters that deer who have 
>>>>survived prior hunting seasons catch on to the begining of one very quickly 
>>>>and become almost totally nocturnal.  Those who refuse to learn, and adapt, 
>>>>end up on the supper table.
>>>>
>>> Once again, you say you are selecting for a trait totally unnatural to
>>> deer.  Being active at night hurts their breeding performance by 
>>> restricting their hours, and wastes their already limited energy reserves
>>> by causing them to miss out on the solar energy and higher daytime 
>>> temperatures, thus increasing their thermal load.

Not true.  Deer are most active at dawn and dusk.  They're normal dormant 
time is from about midnight-1am till shortly before dawn.  They normally 
rest and move during the day somewhat as well.  Generally though they are 
fairly nocturnal to begin with.

Hunting preasure makes them less active during the day.  However, if a cold 
snap triggers the rut, all that goes out the window and you are likely to 
see deer at any time.  As well, deer show an uncanny ability to adapt to 
the movements of their predator.  They know when most of these bipedal 
creatures leave the woods (around noon) and so they come out and stretch.

>>
>>Well, impairing their breeding performance is in line with one of the goals 
>>of sport hunting, i.e. controlling population size.
>>
> Controlling population size, yes.  I still believe this is necessary.  But
> damaging the health of that population isn't.  Especialy at the genetic
> level.  Since the point of responsible hunting is to help the deer and
> make them healthier, altering their behavior like that should be something
> hunters would try to avoid.

No one has been able to do anything but *assert* that damage *might* happen 
so far.  :-)

> 
>>How is it that being more nocturnal 'wastes their already limited energy 
>>reserves'?  How is it that their 'energy reserves' (whatever the hell that 
>>means) are limited?  Being nocturnal simply means that they do most of 
>>their moving about at night.  It doesn't mean that they live in caves 
>>during the day, so how can you justify saying that they miss out on the 
>>solar energy and higher daytime temps?
>>
> Deer eat food and store it as fat.  That is energy reserves.  Deer have
> been shown to live on a very  thin line between life and starvation as
> a normal part of their ecology.  This is even when food is available.
> Thus the energy reserves are limited.  That is why  control of their
> populations is so necessary.  Even a slight food shortage can kill loads
> of them, and severely weaken the rest for the coming year, and all starved
> fawns for life.  

The possibilities and implications of winter starvation are one reason why 
the hunting season happens when it does.  It reduces the population on the 
land, thus making the limited food more accessible to those who survive 
hunting season.

> 
> When deer sleep, they curl into a smaller shape, with less surface to 
> lose heat from.  They let their body temperatures drop, so as to
> expend less energy, and tuck in their noses to minimize heat loss
> due to breathing.  If they are forced to be active at night, when

They are always active at night.  See above.  They just become a little 
less active during the day and a little more active at night.

> it is cold, they can't use those methods to save heat.  They must
> sleep some time, presumably during the day if they are active at 
> night.  With higher temperatures, the heat savings are proportionately

They sleep at various periods, predominately midnight till shortly before 
dawn.
 
> reduced.  That is why they lose out on the daytime.  They should be
> active then, when energy losses due to activity would be less than
> when it is colder at night.

Undisturbed deer aren't very active during the daytime either, except 
during the rut.  The mating season overrides their good sense. :-)

>  
>>And what exactly do you mean by 'increasing their thermal load'?  Either 
>>you have some pretty fuzzy concepts here or you haven't expressed them very 
>>well.
>>
> Heat loss is proportional to the difference in temperatures.  Deer, being
> mammals, have a nearly constant body temperature.  So if a deer at say, 
> 98.6 degrees, awake, and 97 asleep, is in a place when it is 0 degrees
> during the day and -32 at night, it would have a  proportionately lesser
> heat loss if its maxima and minima coincide with those of its surroundings.
> In a mammal, heat loss (thermal load) accounts for about 80% (I forget
> the exact number) of energy expended.  So small reductions in heat loss
> represent fairly major reductions in total energy expenditure.

Personally I suspect that mating activity puts a much higher drain on the 
animals energy reserves than being a little more nocturnal does.

> 
> E.S. 
-- 
John Robinson                  Only criminals, tyrants, and cowards have
robinson@ac.dal.ca                 reason to fear the armed, honest citizen.
DOD #0069
Newsgroups: talk.politics.animals