ABS 2022
Untangling the effects of time and light on wolf spider foraging efficiency
Brett Seymoure1,2,3, Onecia Adams3,4, Kate Frauenheim1,3, Katie Jones1,3, Rachel Rhee1,3, Arjun Sahai2, Leticia Classen-Rodriguez2,3, Stella Uiterwaal1,2,3,5, John DeLong5, Amanda Koltz1, Kasey Fowler-Finn2, Anthony Dell1,3. 1Living Earth Collaborative, Washington University in St. Louis, St. Louis, MO, United States; 2St. Louis University, St. Louis, MO, United States; 3National Great Rivers Research and Education Center, Alton, IL, United States; 4Edward Waters University, Jacksonville, FL, United States; 5University of Nebraska, Lincoln, NE, United States

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 other behaviors. Most daily behaviors of arthropods are cyclical and entrained by light environment. We investigated 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 Drosophila at different times (night, twilight, day) and under different lighting (starlight, twilight, daylight). We tracked wolf spider activity (N=112) and measured respiration across time. Each spider’s foraging success was tested over 9 consecutive days under 3 different time and 3 light treatments. We calculated overall foraging success, the rate of foraging, and individual movement. We hypothesize that light levels and traits drive movement in these visually guided hunters, and movement strongly influences the rate of encounters, resulting in greater predation. As artificial light increases, these findings illuminate the importance of natural light conditions.