Re: Raptors climbing trees?

[Amtoine Grant <rascienz@shaw.ca>]

On 2-Apr-08, at 6:33 PM, Dann Pigdon wrote:
> Dustin Mendus writes:
> > Is there any likelihood of Velociraptor, Utahraptor, or  
> > Deinonychus being
> > able to climb trees? Using their back claws like hooks into the  
> > tree, and
> > moving upward? It seemed quite likely with the Jurassic Park  
> > depiction of
> > Deinonychus(though the wrists are wrong...), but, is it possible  
> > at all with
> > the real thing? Utahraptor or Deinonychus in particular, really.
>
> Dromaeosaur bodies seem like they'd have been fairly stiff and bird- 
> like to me. Having a long stiffened tail, and hips, wrists and  
> ankles all with limited ranges of motion, would have made climbing  
> quite difficult for the larger bodied species. Unless of course you  
> call the occasional mad scramble up something 'climbing'. Smaller  
> dromaeosaurs (below Velociraptor size) may have been luckier, and  
> certainly animals like Microraptor seem to have what appear to be  
> arborial (or at least scansorial) adaptations. However I don't  
> envisage something like Deinonychus leaping gracefully about the  
> tree-tops like a spider monkey.
> Then tere are two things required for an animal to climb; the  
> ability and the desire. Lions and leopards aren't all that  
> different physically speaking, but the latter spend far more time  
> climbing than the former do. On the other side of the coin, compare  
> arborial foxes to their terrestrial cousins. Physically there are  
> few obvious differences, so it seems the arborial nature of one  
> species is governed more by behaviour than physical form. So even  
> if you can determine whether or not a particular theropod *could*  
> climb, that doesn't necessarily mean that it ever *did*.

Of course, we will never know what they "did". Our task should be to  
determine what they were at least possible of doing. True, a full- 
grown Deinonychus leaping from branch to branch MAY be hard to  
realistically imagine. But what about a juvenile? It's hard to  
imagine the majority of behaviors living animals practice, but it  
happens. This question shouldn't be limited to the species, it's also  
a question of ecology(what sort of branches were there to leap to &  
from?). Especially given that there are tyrannosaurs and/or other  
larger predators in most every environment dromaeosaurs are know  
from, ANY escape method should not be ruled out w/o proof of  
impossibility.