Re: Follow-up on Lions of Savuti

[Chris Campbell <Sankarah@ou.edu>]

"Stewart, Dwight" wrote:
> 
> > -----Original Message-----
> > From: Chris Campbell [SMTP:Sankarah@ou.edu]
> > Sent: Tuesday, February 09, 1999 10:11 AM
> > To:   dinosaur@usc.edu
> > Subject:      Re: Follow-up on Lions of Savuti
> >
> > >            Hmmm... Well so much for using that as an analogy for
> > theropods
> > > predating adult sauropods. :-)
> >
> > Presumably they'd have less trouble with juveniles.  Which is what I'd
> > expect them to go for, in any event.
>         @@@@@@@@@@@@@@@@@@@
> 
>            No, I don't.  With modern prey/predator relationships (when the
>prey animal is many X's larger than the predator) it is the very young, 
>the very old, the sick, trapped, or injured who are selected.  

I don't understand how it is you're disagreeing with me.  I did say
juveniles, after all.  I'd expect them to go for other things as well,
but juveniles will be lots more common than the very old, the sick, or
the trapped or injured.  Heck, wildebeest manage to keep a stable
population despite the fact that five hundred thousand of the critters
are born every year.  Most of those wind up as food during their first
year.

>It's simply not in the best interest of a predator to risk serious injury 
>attempting to take down an enormous prey animal.  

I don't think anyone's claimed otherwise.

> Now, I'm NOT saying that predators never act out of desperation, but these 
>don't represent their normal hunting patterns.  A species survives as a 
>successful predator in large part because they are good at exploiting their 
>niche in the environment.

Again, I haven't seen anyone claim anything to the contrary.
 
> > We can't prove anything at all.  All of this is speculation, and can never
> > be anything but.  We still don't know what was up with the fighting dinos
> > in Mongolia, for example, and even though we know a hadrosaur healed wounds
> > from a tyrannosaur bite we still don't know how common active predation on
> > hadrosaurs by tyrannosaurs was.  We never will know these things, and the
> > best we can do is make reasonably informed guesses.
> 
>            Yes, I'd say I agree with that - in the main.  Now, IF we find
> substantial evidence of cooperative hunting techniques among carnivores
> dinosaurs, I would find the "preying on VERY large animals" idea more
> palatable.

I don't see why they'd ever prey on VERY large animals, when juveniles
of all sorts were no doubt readily at hand.  We know at least some of
these guys started out quite small, so there's plenty of food for
everyone.

However, just because they'd go after smaller animals doesn't mean
cooperative techniques wouldn't be useful.  If the herbivores in
question tended toward herds, for example, cooperative tactics of some
sort might be exceedingly useful.  Since issues of size, intelligence,
and physical capability have all been addressed (i.e., claiming that
cooperative behavior was impossible is no longer tenable), the question
remains wide open.  There's no evidence showing therapods hunted
cooperatively, and there's no evidence showing they didn't.  Cooperative
tactics were certainly a possibility, and given the wide range of
therapod types I imagine the behavior showed up at least occasionally. 
Beyond that, we can't say anything for sure.