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rex scavenge (was: DROMAEOSAUR "SICKLE" CLAWS)




On Fri, 12 Sep 1997, Jeffrey Martz wrote:

> 
> > It's more than that,though.  It just wouldn't be efficient to rely
> > primarily on scavenging; there's a reason vultures are the only large
> > scavengers out there -- they can soar all over creation looking for food
> > and it costs them next to nothin in terms on energy expenditure. 
> > Picture a wolf trying the same thing: do you honestly think it could
> > find enough dead stuff to subsist on?  
> 
>      The key word is "find".  The vulture subsists on scavenging partly by
> being able to get to the carrion quickly, but also by being able to FIND
> it quickly.  Vision at high altitudes is a great advantage for finding
> food.  If a land bound creature had could find food as quickly as that,
> and could head in the right direction quickly, it could reach a kill in
> fairly good time.  Yes, it would probably have been picked over some by
> scavengers who ALSO followed thier noses, but it could scare these off.
> Unless the dead animal was actually killed by a predator, the T.rex's
> chances of getting to it FIRST is no less then any other local carnivore,
> and considerably higher with that big olfactory lobe.  As far as having to
> compete with OTHER tyrannosaurs, the distribution of large predators in a
> given area may have been low enough for competition to not be so much of a
> problem.    

You seem to misunderstand the problem (as I see it at least).  I believe
that the point of Chris' argument here was mainly in energy expenditure
(forgive me, Chris, if I am putting words in your mouth).  True, it is
important that vultures find the carrion rather quickly, but MORE
important that they find it while expending very, very, little energy.  

(snip)
>      You don't think T.rex could scare off other scavengers?  And yes, if
> they are lucky vultures may get to a fresh kill before anyone else, or
> only have to deal with a couple golden jackels.  However, if there are a
> number of large carnivores (such as lions and hyenas present) they will
> have to wait thier turn.  Not many african carnivores have the huge size
> advantage that T.rex did over most of the other local carnivores.  This,
> combined with an ability to locate carrion quickly, may have made it a
> more effective scavenger.   

Vultures do have to wait their turn at times, but why?  Because a larger
carnivore made the kill.  Other messages on the list in this vein discuss
the fact that the largest carnivore in an ecosystem today is always the
top predator as well, with very few exceptions (most of which are
influenced by man).  Another message writer(sorry if I don't give you
credit, I'm not sure who you are!) wrote simply, "then who is doing the
killing?"  If we assume that tyrannosaurs were scavenging their meals
(primarily at least), then what other predator is around to kill the large
hadrosaurs and ceratopsians?  Unless you rely on the idea that there were
enough animals dying without predation, just lying around, for the
carnivores to scavenge.  

Flame me, if you will.

Jack