Re: [dinosaur] Energetic cost of foraging flight in parrots

[Dann Pigdon <dannj@alphalink.com.au>]

On Thu, May 18th, 2017 at 3:16 PM, Tim Williams <tijawi@gmail.com> wrote:

> The major fault I find with this particular model is that it assumes
> an arboreal setting.  If _Archaeopteryx_ and _Microraptor_ were indeed
> leaping between branches, one might expect them to have feet
> specialized for perching.  They don't.  The hallux is only modestly
> descended on the metatarsus, and it's certainly not reversed.  So it's
> difficult to envisage how an arboreal foraging protobird would land.
> Take-off is fine.  But without a foot that is adapted for grasping
> branches, the landing would be highly problematic.  

One thing I notice about the species of bird used in the study is that they have
unusually short tail feathers, which would seem to be an adaptation to leaping
about in closely-spaced branches. Most early theropod flutterers appear to have 
had long bony tails that would have made navigating such a cluttered environment
quite difficult, especially if the feathered tail 'frond' lacked the mobility 
of modern
bird tail feathers and couldn't be spread or retracted at will.

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 Dann Pigdon
 GIS Officer
 Melbourne, Australia
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