Phenotypic Plasticity in the Reproductive Characteristics of an Oviparous Snake, Elaphe guttata: Implications for Life History Studies

Previous field studies of squamate reptiles have shown that many life history traits show a significant amount of phenotypic plasticity, especially in response to prey availability. These results were recently supported by laboratory studies on a viviparous garter snake, which showed that clutch size and clutch mass were plastic in response to changes in energy intake, but that relative clutch mass and offspring size were relatively canalized. To determine if these results extend to oviparous reptiles, we conducted an experimental study of phenotypic plasticity in the corn snake, Elaphe guttata. Female corn snakes on a high energy diet produced larger clutch sizes, larger clutch masses, and larger relative clutch masses than did females on a low energy diet, but egg mass did not differ between the feeding regimens. Our data support earlier studies suggesting that much of the observed intraspecific variation in life-history traits of squamate reptiles may be the result of phenotypic plasticity.