Factors Influencing Sex-based Movement Patterns in the Banded Garden Spider, Argiope trifasciata (Forskal, 1776)

Authors

• Brandon R. Marrone, University of Nebraska-LincolnFollow

First Advisor

Eileen A. Hebets

Committee Members

Daizaburo Shizuka, Ian W. Keesey

Date of this Version

4-2026

Document Type

Thesis

Citation

A thesis presented to the faculty of the Graduate College at the University of Nebraska in partial fulfillment of requirements for the degree of Master of Science

Major: Biological Sciences

Under the supervision of Professor Eileen A. Hebets

Lincoln, Nebraska, April 2026

Comments

Copyright 2026, Brandon R. Marrone. Used by permission

Abstract

Movement is a fundamental ecological process shaping how individuals acquire mates, secure resources, and navigate heterogeneous landscapes. In species with extreme sexual size dimorphism (eSSD), such as the orb‑weaving spider Argiope trifasciata, males and females are predicted to experience different movement pressures driven by their reproductive roles. This thesis examines how individual traits and environmental conditions jointly influence movement across both sexes. Across two field seasons, we used intensive mark–recapture methods to quantify natural movement patterns of males and females within mapped prairie plots. The first chapter tested long‑standing predictions gravity hypothesis, which posits that smaller males benefit from enhanced mobility to reduce the costs of mate search. Despite strong theoretical support, within‑species variation in male size did not predict movement frequency, number of webs visited, or distance traveled. Local competitive environments, measured as Web Sex Proportion, similarly failed to explain male movement. These findings suggest that male mobility in A. trifasciata is not shaped by size‑based energetic constraints or perceived competition, challenging assumptions of the gravity hypothesis. The second chapter focused on female movement, historically assumed to be rare in mature individuals due to strong web‑site fidelity. Contrary to this understanding, females frequently relocated, often taking over webs previously occupied by conspecifics. Female body condition did not predict movement behaviors, but environmental variation played a substantial role. Females were more likely to abandon their webs for another nearby web on dry days, they were more likely to disappear from the study site entirely on high‑wind days, and most likely to re‑establish on a different web on hotter days associated with higher prey capture and reduced web integrity. These results reveal that female movement is highly responsive to fine‑scale abiotic conditions rather than intrinsic states. Together, these chapters demonstrate that movement in A. trifasciata is shaped by different forces across sexes: male movement patterns appear decoupled from size and competition, whereas female movements are environmentally driven and more dynamic than previously appreciated. This integrated perspective highlights the importance of combining behavioral, environmental, and life‑history approaches to understand space use in eSSD species.

Advisor: Eileen A. Hebets