The water moccasin, also known as the cottonmouth (Agkistrodon piscivorus), is a venomous, semi-aquatic snake found throughout the southeastern United States. These adaptable reptiles inhabit wetlands, swamps, and various waterways, where they act as predators.
Their Main Meals
Water moccasins are generalist predators, consuming a wide array of available prey. Fish, such as minnows and catfish, form a substantial part of their diet, often targeting slow-moving or injured individuals. Amphibians like frogs, toads, and salamanders are also frequently consumed, particularly by younger snakes.
They prey on small mammals, including rodents like mice, rats, and shrews. Small birds, such as ground-nesting species or fledglings, can also become a meal. Their diet expands to include other reptiles, such as lizards, smaller snakes (even other water moccasins), and small turtles. Young alligators have also been reported as prey.
Younger water moccasins occasionally feed on invertebrates like insects and crayfish. Their opportunistic nature means they will consume almost anything they can overpower and swallow. This includes scavenging on carrion, a behavior not commonly seen in many other snake species.
How They Hunt
Water moccasins primarily employ ambush predation, patiently waiting for prey to come within striking distance. They often lie in wait near the water’s edge or partially submerged, striking quickly when an unsuspecting animal approaches. Their venom plays a crucial role in subduing prey, as it is primarily designed for incapacitation rather than just defense.
The hemotoxic venom breaks down blood cells and tissues, preventing blood from clotting. The snake will typically strike and then hold onto smaller prey until it stops moving. For larger prey, they may strike and then release, tracking the envenomated animal by scent until it succumbs.
Water moccasins use their heat-sensing facial pits, located between their eyes and nostrils, to detect warm-blooded prey, especially effective during nocturnal hunts. Younger water moccasins exhibit a hunting behavior called “caudal luring,” where they wiggle their bright yellow tail tip to mimic a worm or insect, attracting small prey like frogs or fish.
Factors Affecting Their Diet
Several factors influence the specific diet of an individual water moccasin, reflecting their adaptability. Habitat availability dictates the types of prey present; for instance, snakes in swamps have access to different prey than those in rivers.
Seasonal changes also play a role, as prey availability fluctuates throughout the year. Amphibians might be more abundant in spring, while fish activity can vary with water temperature.
The snake’s age and size are also important determinants. Younger, smaller water moccasins typically consume smaller items like insects, tadpoles, and small fish. As they grow, their diet expands to include larger animals. Their opportunistic nature means they consume whatever is easiest to catch and most readily available in their immediate environment.