To test their abilities, the researchers dropped 59 Selenops spiders from either canopy platforms of tree crowns in Panama and Peru. The vast majority (93%) directed their aerial trajectories towards nearby trunks. After landing, they re-oriented themselves and walked head-first towards specific targets.
The scientists say that this type of behavior may have preceded the origin of wings. The spiders are exceptionally thin, and they exploit the powers of lift and drag by spreading their legs wide open. They're even able to right themselves in midair when they turn upside-down. The biologists also witnessed spiders who bounced off a tree trunk, only to recover and resume the glide back down to the surface.