Do Sidewinder Rattlesnakes (Crotalus cerastes, Viperidae) Cease Feeding During the Breeding Season?

Seasonal aphagia (a lack of feeding) can occur if foraging and reproduction occasionally result in conflicting demands on an individual, such that one activity takes precedence over the other. We tested the hypothesis that female and male Crotalus cerastes (Sidewinders) exhibit seasonal aphagia during the reproductive season. We examined the stomach contents of preserved specimens to assess variation in the feeding rates of C. cerastes. Non-reproductive females fed during the early and late stages of the active season, but reproductive females only ate during the first half of the active season. Female Sidewinders fed throughout the early vitellogenic phases of the reproductive cycle, but exhibited a tendency to reduce or cease feeding during the later stages of the cycle (gestation). Prey consumption during early reproductive stages can provide valuable energetic resources for sustaining a female's subsequent breeding activities. However, the physical burden of offspring mass and the concomitant decrease in locomotor efficiency can reduce a female's foraging efficiency in the later phases of the reproductive cycle. Male C. cerastes displayed a trend to feed more frequently during the reproductive season, perhaps because enhancing their energy reserves allows males to travel longer distances and maximize encounter rates with females. The discovery of this intersexual variation in feeding patterns of C. cerastes underscores the importance of descriptive ecological studies to elucidate distinct patterns of life history evolution.