Interest in small robotic devices has soared in the last two
decades, leading engineers to turn toward nature for inspiration and spurring
the fields of biomimetics and bioinspired design. Nature has evolved diverse
solutions to animal locomotion in the forms of flapping flight, swimming,
walking, slithering, jumping, and gliding. At least 30 independent animal
lineages have evolved gliding flight, but only one animal glides without any
appendages: the flying snake. Three species of snakes in the genus Chrysopelea
are known to glide. They inhabit lowland tropical forests in Southeast and
South Asia and have a peculiar behavior: they jump from tree branches to start
a glide to the ground or other vegetation, possibly as a way to escape a threat
or to travel more efficiently. Their gliding ability is surprisingly good, and
one species of flying snake, Chrysopelea paradisi (the paradise tree snake),
has also been observed to turn in mid-air.