The Costs of Combat: Observations of Western Alligator Snapping Turtle (Macrochelys temminckii) Aggression

Patrick D. Delisle^1,*, Eric C. Munscher^2,3, Shelby A. Truckenbrod⁴, Chase Gravatt², Tim Trombley⁵, and Luke Pearson⁶

¹School of Biological, Environmental, and Earth Sciences, University of Southern Mississippi, Hattiesburg, MS 39401. ²SWCA Environmental Consultants, Houston, TX 77339. ³Turtle Survival Alliance, 570 International Boulevard, Suite 124, #252, North Charleston, SC 29418. ⁴Organismic and Evolutionary Biology Program, University of Massachusetts Amherst, Amherst, MA 01003. ⁵Great Lakes Photography, Chatham, MI 49816. ⁶Mississippi Ecological Services Field Office, US Fish and Wildlife Service, Jackson, MS 39213. *Corresponding author.

Southeastern Naturalist, Volume 25, Issue 3 (2026): N56–N63

First published early online: 26 August 2026

Abstract
Intraspecific male–male combat among Macrochelys spp. (alligator snapping turtles) has only been reported in 2 publications, with 1 describing it in captive individuals. We report and describe 1 observation of combating M. temminckii (Western Alligator Snapping Turtle) in Pearl River County, MS, 1 observation in Wakulla County, FL, and 2 observations in Harris County, TX. In Mississippi, combat was observed for 10 minutes in shallow water. In Florida, the mounted individual was bitten aggressively several times over the course of 30 minutes and was able to inflict substantial injury to the aggressor’s eye that likely resulted in permanent damage. In both Texas observations, larger males were observed attacking smaller males restrained inside hoop nets, exploiting their immobility to inflict injury without the risk of retaliation. These observations highlight the risks of male–male combat in Macrochelys spp.

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