Re: New MANIAC book is out! -good/poor flyer

[Mike Habib <habib@jhmi.edu>]

On Feb 21, 2010, at 2:29 PM, Erik Boehm <erikboehm07@yahoo.com> wrote:

> I would suggest that "poor flyers" use flight as an escape method,  
> but not as a normal mode of locomotion.
> A "good flyer" flies to travel from point A to point B.

Ah, but here's the rub: those escape-oriented taxa are the ones with  
the largest flight muscles and strongest skeletons, specifically  
because burst launch is so rigorous. A grouse can glide (albeit not  
with a great glide ratio), but a duck of the same size cannot burst  
launch at a steep angle. Which is the better flyer?
>

> How often do you see the above birds walking around, aside from a  
> very local vicinity where they are foraging for/eating food?
> They fly to travel.

True, but that might say more about ecology and secondary motion than  
flight. Are tropicbirds better flyers than albatrosses, given that  
tropicbirds are poorer at walking? Secretary birds hunt and walk about  
on the ground most of the time, but they soar just as well as more  
arboreal raptors. Are they good flyers or poor flyers?

> Now look at turkeys.... when do you observe them flying? basically  
> never except when threatened.

Indeed. But they can launch vertically at albatross grade body  
weights. That does not strike me as poor.

> I would say if you take a species, put it in an environment devoid  
> of predators(but otherwise like the one it was taken from), and you  
> do not observe the flight "behavior", it is a poor flyer.

Interestingly, though, there are no flightless galliforms in the wild,  
but plenty of flightless ducks and grebes, which are both long  
distance flyers.

> So as to fossils: if it appears flight was a primary form of  
> locomotion-> it was a "good flyer", even if it wasn't as good as the  
> "average" modern bird (use a crow as a reference?).
> If it appears it would only fly when threatened -> poor flyer.

Seems like a good approach at first, but see above. Strong escape  
launching tends to be more derived, not less. Flight as a primary  
movement might mean that walking is reduced, rather than flight  
"improving".

Cheers,

--Mike H.

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