Unexpected Gliding Ability Discovered in Spider Species

Scientists conducting research in the Peruvian rainforest dropped spiders to see whether they could glide and discovered that the large, flat Selenops spiders could do just that. Described by the National Geographic as being as big as a soup tin but as thin as a nickel, these spiders, known as 'flatties', were found to be able to direct themselves towards targets while they fell, using their forelimbs to steer.

The spiders do not use silk to glide, something which other spiders species do by using a dragline to anchor themselves for safety.  The flatness of the Selenops species may be instrumental in their unexpected prowess in gliding, according to the leader of the study, Stephen Yanoviak, who was impressed by the apparent use of steering: "If it wants to turn left, it changes the angle of the right front leg. And if it wants to turn right, it does the same with the left front leg."

A 'Flatty' spider (Selenops sp.)

The study describes an ability not previously known to be exhibited by arachnids, and is a first for science. The gliding technique is thought by the authors of a paper outlining the research to be an adaptation to arboreal living, as opposed to forest floor living, which allows the flatties to right themselves in the air within milliseconds of falling.

The research is described in a newly published manuscript in the journal Interface.

By Jon Fern

Picture credits: Stephen Yanoviak/National Geographic