[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

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

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".


--Mike H.