Effects of Increased Environmental Temperatures on Reproduction in Wild American Alligators (Alligator mississippiensis) in Southwestern Louisiana

Ted Joanen¹ and Mark Merchant^2,*

¹Louisiana Department of Wildlife and Fisheries, Rockefeller State Wildlife Refuge, Grand Chenier, LA 70643; Retired. ²Department of Chemistry, McNeese State University, Lake Charles, LA 70605. *Corresponding author.

Southeastern Naturalist, Volume 25, Issue 4 (2026): 434–451

First published early online: 7 November 2026

Abstract
We analyzed springtime air-temperature data during a 62-year time frame (1964–2025) in southwestern Louisiana to determine the impacts of temperature on the onset of oviposition in Alligator mississippiensis (American Alligator). Prior to 2014, mean springtime temperatures showed no statistically significant trends. However, temperatures exhibited a significant increase after 2014. The mean time of estimated initial oviposition varied with temperature change during the entire study period. Prior to 2014, there was no trend observed in the annual onset of oviposition; however, after 2014, the initiation of oviposition occurred increasingly earlier. Comparison of the onset of oviposition with mean springtime temperature revealed a strong correlation and revealed that oviposition occurs 7 days earlier for every 1 °C rise in mean spring air temperatures.

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