Flooding-induced failure of an invasive Burmese Python nest in southern Florida

Abstract

It is important to understand the factors affecting the reproductive success of an invasive species to estimate population size and develop management plans. There remains much we do not understand about the reproductive biology of invasive Burmese Pythons in both their native and invasive range. Oviposition site selection is an important factor in determining reproductive success as nesting is a vulnerable period in the life of reptiles. Flooding can be particularly influential for nesting outcomes and success of developing embryos in habitats that experience periods of heavy rainfall or seasonal flooding. It is not clear how seasonal flooding may impact oviposition site selection by females or hatchling survival of Burmese Pythons in Florida. On 10 May 2023, a radio-transmitted female python oviposited in a hollow log and during incubation all eggs were completely submerged for variable amounts of time. All eggs were collected (n = 78) and dissected to confirm fertilization and assess the stage of embryo development. Two eggs were found to be infertile, while the remaining fertile eggs contained embryos that died at various stages of development. The observed failure of this python nest was a direct result of oviposition site selection by the female. The frequency at which females lay eggs in suboptimal locations in southern Florida is currently unknown. This maladaptive behavior would suggest Burmese Pythons have fitness levels below theoretical optima.