Which bird thermals the best?

On Mon, 15 Nov 2010 03:59:01 -0800, Scott Alexander wrote:

I thought it would be interesting to ask you good people if anyone has
any knowledge on these issues. Does anyone know which broad winged
birds have better or worse centering techniques that you can use to your
advantage?

About the best I've watched are kites - both the Indian Brown Kites and
the Red Kite that are now spreading across the UK.

You can tell thermal strength by watching them: the stronger the thermal
the more dihedral they use. When its weak their wings are flat and when
its really weak or they think they might undershoot the branch they're
aiming for they have slight anhedral and all the tip feathers are spread
and turned up. They never flap unless they absolutely have to.

The other top birds IMO are storks. I was flying models at a major
contest in Portugal near Beja where the field was dotted by small groups
of them. They were wary and would take off if you got within 50m, but I
never saw them flap longer than it took them to get up 30-40 feet and
they always seemed to slot into something and thermal away. It was a hot,
dry, thermally place, but even so their ability to find a thermal when
scared off at a time that wasn't of their choosing was amazing.


--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Martin Gregorie wrote:
About the best I've watched are kites - both the Indian Brown Kites and
the Red Kite that are now spreading across the UK.

I can't judge it, but I've heard that if there are Swifts, they are
pretty reliably in the core of the thermal (because their food is there).

The other top birds IMO are storks. I was flying models at a major

Not surprizingly, Otto Lilienthal spent a lot of time watching storks.