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

["Augustus T. White" <augwhite@neosoft.com>]

Dann Pigdon wrote:
> 
>         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.

Interesting that the best examples of lethal intraspecific combat come 
from territorial disputes.  Other examples, e.g. chimps, could be used 
for tribal or herd animals, but the deaths are between herds or tribes, 
not within them.  If the thread here on ceratopsians reached any valid 
conclusions, ceratopsians quite possibly relied on a herd-based defense. 
That is, they don't appear to be well-designed for individual defense. 
Therefore we'd not expect to see lethal combat within the group.

I realize I'm piling inference on inference, but we might conclude that, 
if ceratopsians commonly show signs of serious intraspecific damage, they 
might have had a group-territorial organization.

On the other hand, how good is the evidence of intra-specific lethality? 
 A recent Science article suggests that a lot of the more elaborate 
weaponry among animals (e.g. elephant tusks) is designed to display 
metabolic health more than actual combat-readiness.  It would be hard to 
imagine a more elaborate display than some of the the later ceratopsians. 
 And, as someone pointed out, the horn shapes and angles suggest it 
wasn't very functional for defense.

>         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?  :)

Ah, but they tend to kill each other over shoes and cars -- display 
items!  There's a weird insight if you wish.  What if mankind's use of 
tools started out as a mating display?  My spear is bigger than his 
spear, so to speak.  Scary thought, but it would explain Suburbans and 
cellular phones ...

  --Toby White