GANGING CROWS & LIZARDS

[darren.naish@port.ac.uk]

On gang/pack behaviour in corvids, Mickey wrote...

> The owner of the territory will harrass interlopers away from the 
> carcass if it can do so effectively.  In such situations the 
> interlopers call out to attract more interlopers in order to make 
> sure that the territory owner cannot effectively deter them from 
> feeding thus making the carcass up for grabs.  

I recall an article in _Scientific American_ (or may have been 
_American Naturalist_... their formats are unnervingly similar to the 
easily confused) about ganging behaviour in corvids, was published 
some time in the last 2 years. Juvenile ravens ganged together to 
harass pairs of adults that had claimed a carrion find. The juveniles 
mobbed the adults until they were so intimidated as to leave.. the 
juveniles could then share the spoils. Seeing as the juveniles did 
not normally associate with one another, this is a sort of 
opportunistic sociality I suppose. 

As similar 'mobbing' behaviours are seen in monitor lizards (there is 
film of several Komodo monitors bringing down a deer together) and 
crocs, we can bet that it was very probably present in the 
behavioural repertories of extinct dinosaurs. As for TRUE pack 
hunting, a la carnivorans, well, I don't think so.

"Think of it as a resource-holding power thing"

DARREN NAISH Alcock's greatest fan
darren.naish@port.ac.uk