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Re: pterosaurs, bats, flying theropods



Jaime A. Headden wrote:

> the closely related apodiforms like swifts
> and hummingbirds, known for their speed adaptations, have narrow,
> triangular tails with forked margin.

If I remember correctly, the Peregrine falcon is the fastest of all
birds.  What is the shape of its tail?

> There are no small soarers.

What about Frigate birds?

> The mechanic to soaring is in the wing proportions, which minimizes wing 
> effort with loading,

Would you translate this for me please?

> Geese have acheived a size that
> limits their ability to flap, yet migrate, so have become soarers.

The largest bird in the world that flies by means of continous flapping
is a male Whooper swan called 'JAP'.  He is far larger than a goose and
each year migrates between Iceland and Scotland (sometimes Ireland).  As
an aside, about ten years ago, during a gale on the North Atlantic,
'JAP' made one of the most extraordinary emergency flights I've ever
heard about.  Geese also fly by means of continuous flapping and flap at
a faster rate than 'JAP'.  When did geese become soarers?

>   See above. Only some eagles. Gulls and albatrosses are procellariforms,
> and nearly all pelecaniforms have soaring-built wings,

What about condors?

>   Riding thermals is not soaring.

Odd.  That's usually taken as one of the definitions of soaring.  Riding
orographic lift and wave shear are a couple of the other energy
extraction mechanisms used for soaring.

> And gliding is not the same as soaring.

It is identical to soaring, with the only difference being whether the
atmosphere is rising faster than the sink rate.  If I remember correctly
(but don't hold me to this), sailplane pilots usually make the
distinction between gliders and sailplanes at a glide ratio of 25:1, but
it is strictly an arbitrary breakpoint.