Cottonmouth (Agkistrodon piscivorus)


Class: Reptilia
Order: Squamata
Family:    Viperidae
Size:    Length: 1.5 to 6 feet (0.45 to 1.8 m)
Weight: Unknown 
Diet: Primarily small mammals and birds, as well as frogs, fish and other snakes
Distribution: Southeastern United States
Young:  1 to 14 offspring every other year
Animal Predators:  King snake, great blue heron, large mouth bass
IUCN Status: No special status
Terms: No special terms
Lifespan: 18 to 20 years



·         Cottonmouth snakes are also known as water moccasins.

·         They are called cottonmouths because they threaten with their mouths open, showing the white interior.

·         Cottonmouths are the only poisonous North American water snakes.

·         Cottonmouths imitate rattlesnakes by shaking their tails.



Cottonmouths are dark olive or black in colour with a pale belly. The young are born with a slight pattern on their backs which is lost as they age. Cottonmouths belong to the same family as copperhead snakes and rattler snakes. Cottonmouth snakes are pit vipers, which means they have heat-sensory pits located behind their nostrils. These pits allow these snakes to identify warm-blooded prey while they hunt at night. The snakes sense a source of heat and strike. 



Cottonmouths can be found from southeast Virginia to Florida and from the eastern coast all the way west to central Texas. They live in swamps, slow-moving streams, marshes, drainage ditches and ponds, fields, rocky outcrops and forests.


Feeding Habits

Cottonmouths do most of their hunting at night, when temperatures are cooler than during the day. They primarily prey on small mammals and birds, as well as frogs, fish and other snakes. When cottonmouths attack, they hold the prey in their jaws until the venom has been released via the hollow fangs and has entered the bloodstream of the prey. They then release the victim to wait for the venom to take effect—once the prey is dead, they swallow it headfirst. 



Spring is the usual mating season of the cottonmouth, with females giving birth to up to 14 young in late summer. The young snakes are either born live or within a sac that they tear open within minutes of being born. The newborns are more vividly coloured than their parents, with bright yellow tails. They are eight to 12 inches (20 to 30 cm) long and ¾ of an inch (1.9cm ) in diameter. They have to catch their own prey because the mother departs soon after giving birth.



Cottonmouths often spend the day basking in the sun on a rock to get their body temperatures up to a high level in order to aid digestion. Although they often stand their ground when approached, they are normally non-aggressive towards humans and rarely attack unless provoked. Cottonmouths swim with their heads out of the water. If they notice people swimming nearby, they will head in the opposite direction, but if they are stepped on or grabbed while in water, they will bite in self-defence. However, cottonmouths prefer to inhabit marshes and swamps, not clear, open rivers or lakes where people usually swim. 



Cottonmouths are not of conservation concern.



Cottonmouth Wildlife Fact File, IM Pub, US