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Living Sanibel: Cottonmouth

By Staff | Jul 12, 2017

PHOTO BY Kenny Krysko Cottonmouth snake.

The longest known cottonmouth specimen was taken from the Dismal Swamp of Virginia and measured 74 inches. The Florida average is half of that, at approximately 36 inches.

Highly aquatic and an exceptional swimmer, the cottonmouth prefers the numerous swamps, marshes, and wetlands found throughout the Southwest Florida landscape. It is fairly commonly seen at the Audubon Corkscrew Swamp Sanctuary and Big Cypress National Wildlife Preserve in Collier County and Myakka River State Park in Sarasota County.

In these black waters, the cottonmouth is a skilled predator, feeding on an array of animals. It has been known to feed on banded water snakes, mud snakes, fish, frogs, salamanders, sirens, lizards, turtles, baby alligators, birds, small mammals, insects, crayfish, snails and even bats. Because its diet is so varied, it is sometimes referred to as being omni-carnivorous.

When approached, it is not as aggressive as the rattlesnake, and sadly, many similar-looking banded water snakes are killed every year in a lamentable example of mistaken identity. Fatal cottonmouth bites are far rarer than those of rattlesnakes, both because of the smaller size of the snake and the fact that the cottonmouth is generally found in wet environments avoided by humans.

The venom of a cottonmouth is similar in composition to that of a rattlesnake. It is rich with tissue-destructive enzymes and causes extensive bleeding. Immediate emergency medical attention is mandatory.

It is preyed upon by kingsnakes, which are virtually immune to the cottonmouth’s venom, great horned owls, opossums, alligators, snapping turtles and great blue herons.

This is an excerpt from The Living Gulf Coast – A Nature Guide to Southwest Florida by Charles Sobczak. The book is available at all the Island bookstores, Baileys, Jerry’s and your favorite online sites.