E&E Seminar: “Despite morphological differences, sexes display similar antipredator escape performance in an arachnid” by Noah Skelly (UIC)
April 21, 2026
12:30 PM - 1:30 PM
Location
SELE 4289
Calendar
Download iCal FileJoin us April 27th, 2026 at 12:30 in SELE 4289 for an E&E Seminar featuring "Despite morphological differences, sexes display similar antipredator escape performance in an arachnid" by Noah Skelly (UIC - Escalante Meza Lab)
Abstract: Morphological traits influence the behaviors that organisms use to evade their predators. Animals respond to predators using escape behaviors that maximize survival, given the performance capabilities of their morphology. When species are sexually dimorphic in traits related to locomotion, we expect locomotive performance and behavioral responses to differ accordingly. However, the role of intersexual morphological variation on antipredator escape behavior remains poorly understood. In this thesis, we investigated this potential relationship by focusing on one species of the arachnid group Opiliones (Leiobunum aldrichi: Sclerosomatidae) in the field. We hypothesized that sexually dimorphic morphological traits (i.e., body mass and limb length) drive sexual differences in locomotive performance and antipredator escape behaviors. We first quantified morphological differences and determined that males have a smaller body size and longer limb length than females. Then, we experimentally simulated a predator encounter to record performance and escape behavior metrics. Interestingly, males and females had similar locomotive performance (i.e., average velocity) in the initial bout of their escape. They also had similar movement time, freezing time, and distance traveled from the stimulus. Hence, escape behavior is independent of morphological traits, or morphology does not impact performance to an extent that drives differences in escape behavior. To further understand the evolutionary relevance of sexually dimorphic traits in L. aldrichi, we quantified sex ratio bias and found that our sampled population was male-biased. Given intersexual similarities in antipredator escape performance and behavior, a male-biased population suggests that morphological variation is potentially shaped by ecological contexts other than predation.
Date posted
Nov 7, 2025
Date updated
Mar 31, 2026