Term of Award

Spring 2024

Degree Name

Master of Science in Biology (M.S.)

Document Type and Release Option

Thesis (open access)

Copyright Statement / License for Reuse

Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 License.


Department of Biology

Committee Chair

Michele Guidone

Committee Member 1

Risa Cohen

Committee Member 2

Alexander Collier


Leptuca pugilator is a common inhabitant of southeast Georgia salt marshes. This study examined the boldness of Leptuca pugilator across environmental conditions and human impacts. Here, boldness was defined as time taken to reemerge from a burrow after a fear stimulus. I hypothesized that crabs would vary in their boldness based on their surroundings, reproductive timing, and sex. Field and experimental trials were conducted to isolate which factors most influence boldness. Field trials were conducted at four sites varying in human influence throughout the breeding season. During each survey, vegetation height, substrate temperature, average burrow width, burrow count, and distance to/from vegetation was measured. The presence of a vegetative foreground was further investigated in the lab study. Crabs residing at Lazaretto Creek Boat ramp displayed less bold behaviors, possibly due to human activities. Male and female L. pugilator expressed similar boldness, but reacted differently to environmental conditions. Opposing my hypothesis, boldness of male crabs increased with substrate temperature. Female crabs took less time to reemerge when adjacent to wider burrows. Experimental trials found that male crabs reemerged faster when given a foreground of vegetation, although not observed in the field trials. This study provides further insight on fiddler crab behavior as varied by environmental conditions in Southeast Georgia. Results of this study should be expanded on to be inclusive of more populations that face high human influence. Measurements for boldness and peak reproductive periods should be explored further to best identify how they should be classified for future research.

OCLC Number


Research Data and Supplementary Material