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Re: Flight capablities of Archie & Confucius? Not so good...
> > So what business did _Archaeopteryx_ have evolving in
> the first place? It's something I've been wondering about
> quite a lot...
> Didn't it live on islands?
Actually, that's where it gets complicated. All we know is that what seems by
all accounts to be *immature* individuals were drifting around near the shore
The adults *might* have lived on what larger islands were in the vicinity - and
which also had something that might be called "forest" IIRC -, and which are
more likely to have had Archie-predators than the islets where the carcasses
In any case, there are still the about as (in)capable East Asian taxa, which
seem to have done just fine against terrestrial predators (and may actually
have evolved in a decidedly predator-rich environment), but which disappeared
when fully powered ocean-crossing "birds" became plentiful.
But as I said, it just takes an accessible lookout point, and even marginal
unpowered flight capability becomes a definitive winning ticket. Under such
circumstances, it might even be so useful as to make any significant step
towards truly *self-powered* flight a *dis*advantage (energy-wise).
A major factor to remember: no grass, and generally sparse ground-cover. Enough
stuff to get in the way of both your feet and your vision, if you're a small
bipedal theropod; hardly ever enough to hide in.
It is perhaps significant that kakapos are effectively flightless, but still
use their wings to parachute to safety from trees etc without getting hurt. For
all that can be said, Archie had a better wing loading than a kakapo. Also
consider _Threskiornis solitarius_, which was becoming neoflightless but used
downhill glides to escape when pressed. It was (as evidenced by its remains)
more capable of flight than Archie.
We cannot infer Archie's behavior very well, but at least the raw physical
constraints are very much in favor of it having been capable of attack- or
escape-glides from whatever marginally elevated spot it could reach. And it is
remarkable that such behavior is the last vestige of flight capability that is
lost as modern theropods become neoflightless. _T. solitarius_ is a
particularly notable case, but unfortunately the information about is is very
fragmentary. In any case, escape glides seem to have been the only flight
behavior ever recorded for it, but anatomically it would still have been
capable of much more.