[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]
Re: Campbell's even crazier than a MANIAC? (archeopteryx climbing)
> > It is a safe bet that any flapper vert has the
> physical capacity to glide
> > short distances, even if the behavioral phenotype may
> not demonstrate it.
> It depends on how short a distance you're willing to
> call 'gliding'. I suppose a brick can glide for
> short distances (close to the top of it's ballistic arc
> that is, where most of it's movement is
> I still doubt that finches can really glide at all. As
> David Marjanovic pointed out, they tend to fold
> their wings back and turn themselves into ballistic darts
> between active flaps. I suppose you can
> get away with that sort of rotund body plan if your mass is
> small enough.
You can easily see this, it is the sinusoid flight pattern of small passerines
crossing longer distances in level flight close to (meters above) the ground.
They ("finches" for example) can glide open-winged, but their glide ratio still
sucks. Pigeons use it more often - the spread-winged often spread-tailed
oblique descent to a perch, where keeping the wings flush would cause you to
come in at a too high speed and too steep angle (-> having to brake wastefully
early and hardly, or risk severe injury).
Their anatomy allows such postures, they are not too stupid to grok
aerodynamics (the avian brain is arguably the single best technology on Earth
to do this kind of aerodynamic calculations), they do it when it is
appropriate. It does not play a major or even very significant role in their
flying, because small perchers are optimized in a different direction.
Do You Yahoo!?
Sie sind Spam leid? Yahoo! Mail verfügt über einen herausragenden Schutz gegen