Re: "PACK HUNTING" THEROPODS

["Larry Dunn" <larrydunn@hotmail.com>]

From: Nathan Myhrvold <nathanm@MICROSOFT.com>

>Coordinated group foraging behavior does NOT require a lot of 
>intellegence.

It does when discussing vertebrates.  Only the most intelligent 
vertebrates do it.

> If you doubt this, watch film of army ants bringing down
>prey MUCH larger
>than themselves, in what seems to be a coordinated fashion.   
>Theropods
>certainly had the potential to be as smart or smarter than ants!

Ants and other hive invertebrates aren't illustrative here.  It's 
totally apples and oranges. Each organism in a hive is not a separate 
identity but part of a constituent whole.  It's a beautiful arrangement 
but totally alien to vertebrate behavior.  

Example: soldier ants throw themselves into the jaws of the warriors of 
a competing hive to protect larvae.  Why?  They're expendable:  a 
warrior ant does not represent a great investment of group resources.  
Wolves will not similarly end their lives to protect cubs of the pack --  
like all mammals, they may fight hard to protect their young, but 
self-preservation keeps them from parental suicide.  

To emphasize why hive insects aren't illustrative here, try to imagine a 
wolf throwing itself into the jaws of a grizzly bear to protect *another 
pack member's* cubs.

>Many of the highly intellegent "pack hunting" mammilian carnivores 
(wolves,
>lions etc.) actually do far less actual coordination and planning than 
once
>thought.  

[BIG SNIP]

First, I agree that many have anthropomorphized pack hunting, but that 
doesn't require that we then take the argument too far in the opposite 
direction.  

If necessary, pack animals will in fact assist each other in dispatching 
the prey animal.  If smaller prey is scarce, lions will attack a water 
buffalo, and they pile on -- often six or seven lionesses are necessary 
to bring one adult water buffalo down. 

Furthermore, certain degrees of herding strategies are involved.  Wolves 
are the best example, but lions strategize to some degree as well.  And 
watch hyaneas attempt to separate a rhinoceros calf 
from its mother. 

In any event, pack hunters go out *together* to hunt down prey 
animals -- singly or not -- to feed the entire pack.  To broaden the 
definition of pack hunting as you've proposed because some people have 
exaggerated the amount of herding and the frequency of assisted killing 
would be to blur the very real differences in behavior between, say,  
lions and oras.

>Theropods could have been group living and group hunting without true
>cooperation.    All they would need is social tolerance, and the 
ability to
>pursue individual forging strategies - like ants do. Arguments about 
their
>intellegence as a reason to doubt theropod pack hunting are thus rather
>suspect.

Arguments about intelligence are critical in analysing group behavior 
(as discussed, the hive-insect analogy is inapposite).

To reiterate, there is a direct correlation between intelligence and 
cooperative hunting in vertebrates.  Pack hunting by its very nature 
requires cooperation, not simply toleration.  Theropods may have 
congregated on an animal brought down by one theropod (any real evidence 
of this?) and they may have barely tolerated each other at kill sites 
(they don't even seem to have done that, however), but that does't 
constitute pack hunting.

Larry

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