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Re: New bird /pterosaur flight paper in PLoS ONE
----- Original Message -----
From: "Michael Habib" <email@example.com>
Sent: Thursday, April 30, 2009 5:33 AM
Subject: Re: New bird /pterosaur flight paper in PLoS ONE
The authors state that:
"Some studies have proposed that large pterosaurs such as Pteranodon and
Quetzalcoatlus may have had narrow wings similar to those of albatrosses,
and used slope soaring and dynamic soaring . However, our study of
living Procellariiformes as model animals suggests that if pterosaurs
larger than 41 kg (or 5.1-m wingspan) had the narrow wings, they could not
have attained sustainable flight in environments similar to the present."
I missed their proof. Could someone steer me toward it?
Semi-terrestrial predators need a strong ability to launch and gain
altitude, at least for bursts.
Correct, and the big pterosaurs had that strong ability to launch, and a
reasonable rate of climb for flapping bursts long enough for them to travel
for roughly a couple of miles using anaerobic power alone (flapping for
about a mile and then gliding back down during the subsequent mile).
The other major issue, in my mind, comes from the assumptions regarding
launch. Still, after all the years and fine work that have gone into
launch mechanics (Tobalske, Earls, Rayner, etc), we have biologists that
are confused about how launch works in birds at a general level. The
authors suggest that:
"Takeoff is the transition from being supported by something that is
essentially part of the earth's surface to being supported entirely by
aerodynamic forces in flight, and these depend on air flowing over the
wings . Takeoff seems to be the most crucial task for flying birds and
requires more active flapping than level flight because the flight speed
is zero at the beginning and the birds must raise their body mainly by
Overall takehome message (in my opinion, anyway): Nice data, neat
analysis, possible limit for procellariiforms. Application to pterosaur
is, however, quite weak.
Yeah. More like nonapplicable.