Cottonmouths (Agkistrodon piscivorus) are semi-aquatic pit vipers found across the southeastern United States. These reptiles are carnivorous predators that have adapted to life in and around water. Their diet is diverse, reflecting their ability to hunt various animals within their wetland habitats.
Primary Prey
Cottonmouths primarily consume aquatic prey, with fish and amphibians forming the bulk of their diet. They actively hunt a variety of fish species, including minnows, sunfish, bass, and catfish.
Amphibians like frogs, such as southern leopard frogs and bullfrogs, along with salamanders and tadpoles, are also frequently eaten. Cottonmouths often capture fish by cornering them in shallow water, often against banks or under submerged logs. They are also known to take advantage of drying water bodies, where fish and tadpoles become concentrated and easier to catch.
Varied and Opportunistic Diet
Beyond their primary aquatic prey, cottonmouths are highly opportunistic, adapting their diet to available food sources. They consume a range of other vertebrates, including small mammals such as mice, shrews, and rats. Birds, particularly young birds or those found near water, and their eggs, also become part of their varied meals.
Their diet extends to other reptiles, including lizards, small turtles, and even young alligators. Cottonmouths are known to prey on other snakes, including non-venomous water snakes, copperheads, and even rattlesnakes. Cannibalism has also been observed, especially when other food is scarce. Unusually for snakes, they also scavenge on carrion, such as dead fish.
Factors Affecting Diet
Several factors influence the specific diet of a cottonmouth, including its age, the habitat it occupies, and seasonal changes in prey availability. Their diet changes as they grow. Juvenile cottonmouths may consume more insects or small amphibians and often use their bright yellow or greenish tail tips to lure small prey like frogs and lizards within striking distance. As they mature, cottonmouths tend to target larger prey items.
The specific types of prey available in a cottonmouth’s habitat also dictate its diet. Cottonmouths inhabit diverse aquatic environments, from swamps and marshes to ponds and streams, and the local abundance of fish, amphibians, or small mammals will shape what they eat. Seasonal fluctuations can impact food availability; cottonmouths capitalize on concentrated prey when water bodies begin to dry up. Studies have also indicated differences in diet between sexes, with adult male cottonmouths consuming more fish, while adult females may primarily prey on other snakes.