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Re: [Re: Theory on ornithoptering and could Archie do it ?]

That bit about Archie's size makes sense. It kinda shoots down this theory, but 
it makes sense. After all I don't know of many crows (which Archaeopteryx is 
supposed to be the size of) that eat insects, or only insects.

As for the Sugar Gliders, I had thought that they were mainly nectar drinkers. 
As you can tell I don't take care of any myself.

Out of curiosity what insects do they eat? Mosquitoes? Dragonflies?

Anyway thanks for the critique. It's always helpful to get someone else's 
perspective on these things.

Looks like it's back to the old drawing board for me.

Oh I know. In Archie's time, the insect life was alot larger. Dragonflies with 
meter long wingspans and such. Then again. Maybe not.

Archosaur J
m_troutman@hotmail.com wrote:
> <<Well from the information that I've gleamed off of sugar gliders...>>
>     Do you happen to own sugar gliders too?
> <<and draco lizards, it seems that they glide from tree to tree for two 
> main reasons:
> 1: It's the fastest way to get from point A to point B
> 2: It is a highly effective way of avoiding predators.
> Both of these animals don't seem to capture food by gliding. In fact 
> when one thinks of it, gliding isn't the best way to catch insects.>>
>      Hold up.  Sugar gliders in the wild can glide up to 300m and can 
> catch insects in mid-air and the dark ( this is the way that they catch 
> the majority of the their insect food since they do not have a 
> chameleon-like tongue ).  Your points #1 & #2 are very good points and i 
> suspect that #1 has the most to do with the problem.  
> <<Think about it. A glider needs the momentum of their falling bodies to 
> keep them going. Some like dracos are efficient at turning and keeping 
> airborne for a long distance. But the insects that a glider would chase 
> are powered flyers. Many insect flyers like bees and flies are not only 
> very fast, but very agile too. >>
>      Sugar gliders depend on the momentum of their bodies to keep going, 
> yes,  but they also have some huge skin folds and an airfoil shape to 
> gain lift and distance ( as well as the height of the tree that they 
> jumped off of ).  Sugar gliders are also great at maneuvering.  Mine was 
> crawling around somebody and it jumped to me, I, oblivious,  ducked down 
> to grab something, and she glided right over me.  Since she was heading 
> for a bookcase, she performed a miraculous turn and only lightly tapped 
> the bookcase and fell to the floor.  Sugar gliders have to be good at 
> turning to be able to catch their insect prey and to land on flowers.  
> <<That's the problem with chasing an ornithoptering insect. They have 
> that nasty habit of zig zagging and darting in all kinds of weird 
> directions. As a glider your running on borrowed time, these insects on 
> the other hand (by ornithoptering) are making their own time. Doesn't it 
> make sense to find a better way to chase them.>>
>      Of course this is assuming that basal birds chased after insects.  
> <<What if that Archaeopteryx that flew down from the tree and just 
> missed that darting dragonfly, turned around and, with some short flaps 
> to regain speed, went after it again.>>
>      Greg Paul has discussed the prospect of Archaeopteryx as an insect 
> chaser and he came to these basic points:
> 1)  Archaeopteryx could not live on the diet of just insects because it 
> was too big to support itself on just insects ( and let me point out 
> that even if it was bradymetabolic,  this would still hold because the 
> larger size of Archaeopteryx compared to >most< other insectivores still 
> holds ) and that there cannot be given that there would be enough 
> insects availible for Archaeopteryx.  
> 2)  Insect flight is comparable to WWII Spitfire flight whereas 
> Archaeopteryx flight is comparable to a slow, early Wright flier. 
> <<I'm not suggesting a complete ornithopterer here, but just the 
> occasional flap to help it keep up the chase. This occasional flap would 
> no doubt show up as a benefit and the evolution of powered flight 
> commences.>>
> Archie's body is not streamlined like the body of sugar gliders for 
> example.  Sugar gliders are compact even during gliding.  
> <<Now from what I've heard Archie is missing that enlarged sternum for 
> it's wing muscles, so it is said that it can't fly.>>
> Arcaheopteryx bavarica has an ossified sternum and as I pointed out 
> previously on the list,  Archaeopteryx seems to have most of the 
> osteological and myological improvements for flight. 
> <<Even a weak flap, could be an advantage. Especially when trying to 
> keep up with a fast moving insect.>>
> Plus, if early bird flight was concentrated on banking, then the wings 
> would have a greater amount of movement than seen in Archaeopteryx.  
> I applaud the originality of this theory ( Ostrom proposed something 
> like this for the cursorial origin of bird flight,  but it is different 
> ) and even though I find it flawed,  keep 'em coming!!! It was a pretty 
> good idea.
> Matt Troutman
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