Hummingbirds don't open their
feathers on the 'upstroke' when they hover. This is also true of other
birds when using the 'momentum reversal' technique for hovering. And
it's quite possible that some small pterosaurs could hover for short periods
using camber inversion on the 'upstroke', but I haven't attempted to
calculate the hovering beat kinematics for small pterosaurs, so that's just
speculation on my part.
HP Jim Cunnungham wrote:
Please describe to me the technique
that Quetzalcoatlus northropi uses while landing on a flexible
cycad or palm branch.
reply: <I didn`t mean to imply that all pterosaurs
landed on cycad branches,...only the smaller
inversion? Do you think it was possible?>
as an aside, Quetzalcoatlus species, with a head/neck length of about
8.2 feet and a length from notarium socket to acetabulum of about 12.25
inches, doesn't appear to have been 'top heavy'. Perhaps I'm missing
<by "top heavy", I`m referring to
everything above the balance point of the hip joint> I think that all
pterosaurs must have come down pretty hard on their forepaws when
<PS...I`m still looking into exactly what birds do
when they land. I don`t think they all hover either. Just been observing
bluejays landing at the feeder. They do seem to go into a stall just before
landing.Can`t see it up close, but the alula must play a significant
role.Also the ability to absorb the shock with the leg muscles. It is not a
simple process, but I still can`t see how pterosaurs could have accomplished
a foot only contact landing in a relatively stiff perch (despite the
pterodactyls in JPIII !).
pps Sad news to here about S. J. Gould passing away.
(was going to write him about some of my ideas,...guess I waited too