About the Cottonmouth Drawing
About the Cottonmouth Drawing
The first baby Cottonmouth I ever caught confused me. With its bold reddish-brown crossbands and bright yellow tail, it looked at first like a particularly strange Copperhead. The resemblance makes sense: the two species are close relatives, and their young share similar patterns and use brightly colored tail tips to lure frogs and other small prey within striking distance. As Cottonmouths mature, many become progressively darker until the juvenile pattern is difficult to see.
Cottonmouths, also known as Water Moccasins, have been among my favorite snakes for many years. I have encountered and handled numerous individuals during fieldwork and have always been drawn by their chunky build, variable patterning, broad diet, and distinctive defensive behavior.
They are strongly associated with wetlands but are not limited to eating aquatic prey. Cottonmouths consume fish, frogs, salamanders, turtles, snakes, birds, mammals, and carrion. Their willingness to eat animals they did not kill makes them unusually opportunistic among snakes. A Cottonmouth may hunt along the water’s edge, capture prey in shallow water, or simply investigate the scent of a dead fish washed onto shore.
Their best-known behavior is the warning display that gives them their name. When threatened, a snake may coil, raise its head, and hold its mouth open to expose the startlingly pale lining. It may also flatten its body, vibrate its tail, release musk, or strike without biting. The display is dramatic precisely because it is intended to prevent a closer confrontation.
Cottonmouths nevertheless have an enduring reputation for aggression—chasing boats, attacking swimmers, and pursuing people through swamps. Whit Gibbons and I decided to test that reputation experimentally with free-ranging snakes. Science occasionally requires unusual methods, and in this case those methods included deliberately standing beside venomous snakes, stepping on them, and picking them up with an artificial human hand.
We wore snake-proof boots (well, the label said they were snake-proof) and conducted three tests increasing in stress to the snakes. We stood beside snakes with a boot touching them, then restrained them by stepping lightly on the middle of the body, and then lifted them with snake tongs disguised as an arm and hand – with a padded sleeve and leather glove (even a wrist watch). None of the snakes merely stood beside ever bit the boot. Only one of the 22 snakes stepped on attempted to bite, and even when lifted with the artificial hand, only 13 of 36 bit it.
Most tried to escape or relied on gaping, tail vibration, musking, striking without contact, and other warnings. Our results did not mean that Cottonmouths cannot or will not bite—their venom is medically significant and they must be treated with respect. They did show, however, that an animal famous for aggression remained surprisingly reluctant to bite even when we subjected it to treatment no sensible person should ever imitate. I always tell people that if you stepped on me and picked me up, I’d bite you every time. Thus, I’m much more aggressive than a cottonmouth.
Some of the most extraordinary Cottonmouth research has taken place on Seahorse Key, a small island off Florida’s Gulf Coast studied extensively by Harvey Lillywhite and his colleagues. Thousands of pelicans, cormorants, herons, and other waterbirds once nested above an unusually dense population of Cottonmouths. Fish accidentally dropped or regurgitated from the rookery fell to the ground, where the snakes scavenged them. Marine fish became the principal source of energy for many of the island’s Cottonmouths.
The relationship may even have benefited the birds. Cottonmouths gathered beneath the nests for fallen fish but also ate rats that might otherwise have climbed into the rookery to prey on eggs and chicks. Instead of the more familiar island story of snakes devastating a bird colony, the birds effectively fed the snakes, and the snakes may have helped protect the birds.
The island presented another challenge: it had virtually no dependable source of fresh water other than rain. Cottonmouths lack the specialized salt glands that allow some marine reptiles to eliminate excess salt, and they cannot maintain themselves by drinking seawater. The island snakes depended on temporary freshwater collected after storms and were more likely to be dehydrated as the time since rainfall increased. Experiments also showed that they strongly avoided salty and brackish water—a useful response for an animal surrounded by water it cannot safely drink.
In 2015, the waterbirds abruptly abandoned the Seahorse Key rookery for reasons that remain uncertain. The rain of fish stopped. Researchers subsequently found Cottonmouths that were thin, weak, dying, and in some cases eating one another. The event revealed how completely an abundant population of venomous predators had come to depend on food delivered accidentally by birds overhead.
In Fair Warning, the boldly patterned coils surround the raised head and brilliant interior of the mouth, creating a dramatic contrast against the dark background. I developed the composition from two reference photographs by W. W. Lamar, combining the snake’s intricate markings with the display that has defined its public image.
The title reflects the real meaning of that open mouth. It is not an announcement that the snake intends to pursue or attack. It is a clear request for distance—an unmistakable warning that gives another animal, including humans, the opportunity view it from a distance only.
Fair Warning is a graphite-pencil wildlife drawing of a Cottonmouth, or Water Moccasin (Agkistrodon piscivorus), by Michael E. Dorcas for Tantilla Art. Reference photographs courtesy of W. W. Lamar.