Feeding preferences and responses to prey in insular neonatal Florida cottonmouth snakes

Cottonmouth snakes residing on certain Gulf coastal islands of Florida feed largely by scavenging fish that are dropped or regurgitated by colonial nesting birds. Because of the relative isolation of these snakes and their long association with bird rookeries, it is of interest to inquire whether snakes exhibit any dietary preference, or whether consumption of fish remains strictly opportunistic. Here we examine whether there are differences in prey acceptance between insular and mainland naive, neonatal cottonmouths, and whether insular snakes develop preferences for particular prey items. We report that both insular and mainland snakes accept a range of similar prey items including fish, mice and lizards. We also report that naive insular neonates tend to accept fish earlier following birth than they accept mammalian prey. When naive neonates are fed only a single specific prey item, fish or mammal, during the first year of life, individuals preferentially follow odors that are associated with the sole dietary prey to which they have been conditioned. However, following conditioning on either prey category (fish or mice) these snakes also eat the non‐conditioned prey (mice or fish, respectively) when presented with the opportunity. Our results suggest that young cottonmouths might adjust foraging strategy to match prey availability, while retaining flexibility in feeding behavior based in inherent dietary breadth. Thus, the insular population can occupy a broad trophic niche while fine‐tuning foraging behaviors to match the local conditions.