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Re: Fw: Theropod vs. synapsid: golden eagle kills sika deer in Russia



On Tue, Sep 24th, 2013 at 2:49 PM, Jura <pristichampsus@yahoo.com> wrote:

>  I'd argue that they probably represent typical behaviour more than atypical 
> just due to the
> sheer rarity of fossilization. 

There is also the argument that because fossilisation is so rare, we generally 
lack a large enough 
sample size in order to confidently say anything about typical behaviour. 
Catching an eagle in the 
act of killing a deer with an automatic camera is just such a rare event. 
No-one would suggest that 
it represents typical golden eagle behaviour though.

Most predators prefer prey that offer the most rewards balanced with the least 
risk to themselves. 
Even when the odds seem to be in favour of the predator, caution is still often 
taken. Venomous 
snakes will usually bite and release rodents quickly, to prevent the risk of 
them biting back. Great 
white sharks ambush pinipeds from below, also using a quick bite-and-release 
strategy that 
minimises the risk of injury to the predator. Tackling prey of similar (or 
greater) body mass seems 
to be a rarity amongst modern large predators, unless the predators outnumber 
the prey 
significantly.


> >> From: Dann Pigdon <dannj@alphalink.com.au>
> >>To: dinosaur@usc.edu 
> >>Sent: Monday, 23 September 2013 6:27 PM
> >>Subject: Re: Theropod vs. synapsid: golden eagle kills sika deer in Russia
> >> 
> >>
> >>Golden eagles usually only resort to tackling such risky large prey during 
> >>the winter, when
> smaller 
> >>prey become scarce. If given a choice, they'd much rather be tackling 
> >>something smaller and
> less 
> >>risky (as would any carnivore).
> >>
> >>It makes you wonder whether some of the predator/prey associations infered 
> >>from the fossil
> record 
> >>(Deinonychus/Tenontosaurus, Velociraptor/Protoceratops, etc) represent 
> >>typical behaviour, or 
> >>whether they represent rare occurances born out of occasional desperation.

-- 
_____________________________________________________________

Dann Pigdon
Spatial Data Analyst               Australian Dinosaurs
Melbourne, Australia               http://home.alphalink.com.au/~dannj
_____________________________________________________________