Video: Spiderman, Eat Your Heart Out

In the midst of a hunt, a salticid spider catapults itself across an opening in the forest canopy and drops onto an adjacent tree leaf to chase after its prey. It’s not a blind leap of faith. Previous studies have shown that these jumping spiders attach a silk thread to their launch pad as a safety line if they unexpectedly fall. Scientists wanted to understand how these silk lines change the motion of the arachnids’ jumps, so they collected 27 Hasarius adansoni salticids from Taiwan; 22 did use silk lines and five did not. The team built a jumping platform 18 cm in height and a 3.5-cm-shorter destination platform about 7.5 cm away. They filmed each spider jump three times using a high-speed video camera. During the jump, the spiders with the silk lines stayed airborne longer, decelerated more, and completed a smoother landing than those without silk lines, researchers report online today in the Journal of the Royal Society Interface. The results suggest that silk threads can function as more than just a safety line; they can stabilize a spider’s body during a jump and prepare them to stick the landing. The less time the animals need to finish their landing, the more quickly they can scurry along and successfully capture their prey.