Meeting Abstract

100-5   11:00 - 11:15  Untangling the effects of time and light on spider foraging efficiency Seymoure, BM*; Adams, O; Frauenheim, K; Jones, K; Rhee, R; Sahai, A; Classen-Rodriguez, L; Uiterwaal, S; DeLong, J; Koltz, A; Fowler-Finn, K; Dell, A; Living Earth Collaborative, Washington University in St. Louis, St. Louis, MO; National Great Rivers Research and Education Center, Alton, IL; Washington University in St. Louis, St. Louis, MO; Washington University in St. Louis, St. Louis, MO; Washington University in St. Louis, St. Louis, MO; Saint Louis University, St. Louis, MO; Saint Louis University, St. Louis, MO; University of Nebraska, Lincoln, NE; University of Nebraska, Lincoln, NE; Washington University in St. Louis, St. Louis, MO; Saint Louis University, St. Louis, MO; National Great Rivers Research and Education Center, Alton, IL brett.seymoure@gmail.com

Light dictates animal behavior through light dependent systems such as circadian rhythms and vision. Circadian rhythms dictate metabolism and motivate foraging whereas visual abilities guide foraging, mating, and many other vital behaviors. Most behaviors of arthropods are cyclical and entrained by light environment, which varies throughout the day. It is currently unknown how organisms from different temporal niches (diurnal vs nocturnal) cue into time and light levels for foraging. We tested functional responses of diurnal and nocturnal wolf spiders foraging on flightless Drosophila at different times (night, twilight, day) and under different lighting (starlight, twilight, daylight). We first automatically tracked the activity pattern of each wolf spider (N=112) and then measured respiration, as a surrogate for metabolism, for each spider across daytime, twilight, and nighttime. Lastly, we measured eye morphology and retinal physiology of each spider under different light intensities. Thus, we examine hypotheses on individual variation (size and visual traits) influencing foraging through real-time video tracking of predators. We hypothesize that light levels and visual abilities drive movement in these visually guided hunters, and movement strongly influences the rate of encounters, resulting in greater predation. As artificial light continues to expand spatially and in intensity, these findings illuminate the consequences of unnatural light.