Re: Cursorial adaptations (was T.rex and elephants)

[Dann Pigdon <dannj@alphalink.com.au>]

Casey wrote:
> 
> > >
> > > How, then, do you explain Pachyrhinosaurus?  I can't see whatever it
> had on
> > > its snout being much use except in shoving matches.
> > > --
> >       Rhinos and elephants also have head-to-head shoving matches,
> > (no not rhino v's elephant, excuse my ambiguous syntax) but they manage
> > to avoid doing any great damage to each other from horn or tusk.
> > Watching such displays it is a miracle that they don't at least put
> > an eye out or something, but since these creatures have grown up
> > learning how to handle their weaponry they seem to be adequately
> > skilled at avoiding unnecessary injuries.
> >
> > --
> > ____________________________________________________
> >       Dann Pigdon
> >       Melbourne, Australia
> *********************************************************************
> 
> Another thing to remember is that most animals will try to avoid
> intraspecific confrontation, and if they do confront one another they will
> do their best to not hurt one another.  Confrontation is very energetically
> expensive, if they confront one another then that is energy that they will
> not be able to use when it comes time for the important part of passing on
> their genetic material.  Keep in mind that not only do other males (or
> females depending on the species) not want a rival male/female from mating
> with females/males, but the females/males  don't tend to be very receptive
> and put up a little struggle (whether it be a chase like in some mountain
> sheep, or require an elaborate mating dance as in some birds).  Just a
> point to ponder.
> 
> Casey T.
> TUCKERCJ@MUohio.edu
> Miami University
> Oxford, Ohio

        I think everyone has heard the old adage that animals will
avoid intraspecies fighting at all costs, and for the most part
it may be true. However a recent documentary I saw on rhinos was
quite an eye opener. Apparently rhinos quite often kill each other
in territorial disputes. I heard of one male that had to be put
down by park officials somewhere in Africa because it repeatedly
attacked and killed other rhinos that strayed into its territory.
Of course rhinos have become lumped together in unnatural densities
in wildlife reserves, so perhaps this unnatural stress contributes to
the agression. 
        Male hippos will also fight to the death in quite bloody
confrontations, and crocodiles often kill each other. I don't
know about jungle fowl in the wild, but roosters in cock fights
don't seem to need much encouragement to try to kill each other.
Lion males will kill each other if they can to claim a pride
of females, and then kill any unwanted cubs. Hyaena society seems
to be based on violence, with the biggest and toughest females
dominating.
        And what of the ultimate example: humans. We kill each other
for the most trivial of reasons.
        Confrontation is energy expensive, as you suggest, however
sometimes the outcome of a fight to the death is worth the risk.
Most fights to the death seem to be for either access to females
or for territory. Territory often equates to food procurement.
Could that be why sex and food seem to figure so highly amongst young
human males?  :)
-- 
____________________________________________________
        Dann Pigdon
        Melbourne, Australia

        Dinosaurs Reconstructions:
        http://www.geocities.com/capecanaveral/4459/
        The Australian mirror:
        http://www.alphalink.com.au/~dannj
____________________________________________________