Leaping lizards use their tails to control their body orientation actively when they leap, reports a study published in Nature. The work may provide inspiration for the next generation of manoeuvrable search-and-rescue robots.

Recent research has suggested that geckos use their tails to stabilize themselves during climbing and gliding, but evidence from studies of lizard tail loss is less clear. Robert Full and colleagues video-recorded red-headed Agama lizards leaping towards a vertical surface after vaulting on an obstacle with variable traction, designed to produce different degrees of disruption to the lizards’ body angular momentum. They also produced a lizard-sized robot (‘Tailbot’) with a removable, active tail that uses sensory feedback to stabilize pitch as it drove off a ramp.

The authors show that lizards control the swing of their tails in a measured manner, using sensory feedback, to redirect angular momentum from their body to their tail, stabilizing body attitude in the air. The results, combined with mathematical modelling, also support John Ostrom’s 1969 hypothesis that theropod dinosaurs, such as Velociraptor mongoliensis, used their tails as a dynamic stabilizer during rapid or irregular movements.