Animals use withdrawal and escape responses to retreat from threats. Looming stimuli, which represent the approach of a predator, evoke an escape response in jumping spiders that is mediated primarily by visual cues. The majority of studies have focused on spider predation toward prey; only limited studies have explored the escape response. The goal of our research was to determine the strategy used by jumping spiders, Phidippus regius, to escape from looming stimuli. In particular, we sought to determine whether jumping spiders employ jumping as part of their escape repertoire. Looming stimuli were created by using the controlled projection of a 3” black polyurethane ball (1 m/s,45 degrees angle, against a white background) toward jumping spiders (Phidippus regius, n=9), without actually hitting the spider. The direction of “attack” was varied in 45-degree increments, totaling 8 angles, around the spider. The resulting response was captured from above with high speed video (300 fps) and automated software particle tracking was used to quantify the location and orientation of the spider throughout the escape response. Looming stimuli consistently evoked translation, but not turning. The angle of translation depended significantly on stimulus direction. Typically, following initial translation the spider executed one or two movements that appeared linked to the stimulus, often ending in a position that faced the looming object. Importantly, three of the spiders sometimes jumped away from the looming stimulus, a movement previously reported only associated with prey capture. These preliminary results suggest jumping spiders may use specific, diverse, multi-stage strategies to escape from looming stimuli. Further, their name-sake behavior, jumping, may be employed for both predation and escape.

Additional Abstract Information

Student(s): Victoria Gaudin

Department: Biology

Faculty Advisor: Dr. Corey Cleland

Type: Oral

Year: 2019

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