Jumping Spiders Alternative Turns in the Abscence of Visual Cues

Abstract

The abilities of four species of diurnal jumping spiders (Helpis minitabunda, Portia fimbriata, Trite auricoma, and Trite planiceps) and one species of nocturnal clubionid spider (Clubiona cambridgei) to maintain approximately straight paths by alternating turns in the absence of visual cues was investigated. Under infra-red light (observed using infra-red video), individual spiders were run through a maze comprising a single forced turn and then a choice of turning in the same or opposite direction to the forced turn. At the second (free) turn, each species turned in the direction opposite to the forced turn (i.e., alternated turns) more frequently than it turned in the same direction. There was no evidence that species differed in tendency to alternate turns. In nature, jumping spiders may use this ability to navigate in the absence of visual cues when foraging or escaping predators in darkness. It is suggested that alternation of turns by jumping spiders depends on proprioceptive information gathered during previous turns. INTRODUCTION