http://www.technologyreview.com/blog/arxiv/26103/?p1=Blogs

Today, Zsuzsa Ákos at Eötvös University in Hungary and a few pals
suggest another approach inspired by videos and GPS tracking of peregrine
falcons in flight. It turns out that these masters of thermal soaring employ a
counter-intuitive strategy: instead of spiralling in one direction to stay with
a single thermal, they constantly change the direction of their spirals.

At first glance, that seems odd. Change the direction of your spiral and you
immediately fly out of a thermal. But Ákos and co have simulated this strategy
and say there is a method in this madness.

The key is to recognise that the atmosphere is filled with thermals that are
distributed in 3D space in complex ways. According to their simulation, the
reason why the direction change works so well is that it allows the flier to
sample the volume of the atmosphere more effectively, making it more likely that
it will find a better thermal. Crucially, this works particularly well when
turbulence is present.

Thanks to Gary Osoba