RE: Comments?

[Derek Tearne <derek@nezsdc.fujitsu.co.nz>]

> 
> > A lion is not much bigger than a hyena. Either could kill the same game.

> My impression is that lions are much bigger. At least a lion can kill a
> hyena (as was shown in the show).

Most people have a visions of the Hyaena as being a dog sized animal,
a bit like a Great Dane.  Having seen a Hyaena loping along next to a 
car, it's haunches and head above roof level I can attest that they 
are large animals (the occupants of the car looking up at the head 
very nervously, undoubtedly wondering is it's true that Hyaena's jaws 
can cut through steel...).   

If it's the same TV show that I saw it was made fairly clear that the 
two kinds of animals are about the same size, the Hyaena shorter but taller.  
The largest male lions are the biggest of all and the documentary featured
a male lion who's role in the pride was Hyaena killer.  This particular 
individual was significantly larger than most of the other lions.

Male lions are larger than female lions (this is a unique situation 
among felines) however, when discussing competition between the two 
species one must remember that it is the _female_ lions who do the 
actual hunting.

> > By process of elimination, it must be the small theropods. Several
> > problems: 1. there is no conclusive evidence that smaller theropods hunted
> > in packs,

> Agreed. But is there conclusive evidence all small theropods didn't hunt
> in packs?

They might have hunted in packs so they must have?  

To compare with modern felines.  Lions are pack hunters, so are Cheatahs
(which live in a similar environment.  Most of the felines are solitary
hunters (or hunt in pairs). 

Pack behaviour is likely to leave more evidence in the form of tracks (the 
trace fossils of the small therapods running and leaping around a sauropod 
for instance) than solitary hunting.  If future palaeontologists found 
tracks of a lion hunt and extrapolated that behaviour to all the felines
or (worse) to mammalian predators in general they would be quite wrong.

Extrapolating on size also appears fraught with problems.  Most of 
the discussion about carnosaurs appears to be small = pack hunter 
(Dienonychus), large = solitary (Tyrannosaurus).  Yet modern analogues
would say large = pack hunter (Lion, Hyaena), small = solitary (Fox, 
domestic cat) with the medium sized ones employing either method.

With mammals it would seem that most predators are solitary (or hunt 
as pairs).  

Perhaps it was the same with dinosaurs.

--- Derek

---
Derek Tearne.                                           derek@fujitsu.co.nz
Some of the more environmentally aware dinosaurs were worried about the
consequences of an accident with the new Iridium enriched fusion reactor.
"If it goes off only the cockroaches and mammals will survive..." they said.