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The Eastern Coral Snake
The Eastern Coral Snake Micrurus fulvius (Linnaeus, 1766)
Robert George Sprackland, Ph.D.
Family: Elapidae, venomous snakes that include cobras, kraits, mambas, brown snakes, tiger snakes and coral snakes.
Comment: The name "Micrurus" means "tiny tail," and "fulvius" means "reddish-yellow." You can find additional information in the web of life section of http://www.curator.org/ on the Internet.
Appearance: A distinctive snake with broad black, red and yellow bands that completely encircle the body. The snout is broad and blunt, and the head is only slightly broader than the neck. The eyes are moderate, and completely contained within a black band. The body is nearly cylindrical. Coral snakes lack a loreal scale, which may help in identification when comparing wit harmless mimics. The loreal is a moderately large scale that lies on a line between the snake's eye and nostril. Look at a king snake or milk snake and you will see the scale. No elapid snake has a loreal scale. Eastern coral snakes have no teeth in the upper jaws except for the pair of venomous fangs.
Coral snakes grow to an average size of some 45 inches, but some giants have been recorded that approached four feet in length.
Coloration: Eastern coral snakes may be confused with scarlet snakes and some king (milk) snakes. However, in coral snakes, red and yellow bands are in contact (think about the warning colors of a traffic light) and there is no red coloring on the head. The tip of a coral snake's snout is black. These comments only pertain to coral snakes in the United States; many Central and South American species have different patterns in which yellow and red bands are not in contact.
On very rare occasions, completely black (melanistic) specimens may be encountered.
Distribution: Specimens are found in a variety of habitats in the southeastern United States, from northern North Carolina west to mid Texas and south to southern Florida. The range extends south into eastern central Mexico.
Subspecies: Several subspecies are recognized, but only two are natives. The eastern coral snake (Micrurus fulvius fulvius) has brighter red markings with little if any black in the red bands, and the second black band is thinner, not reaching the parietal scales on top of the head. The Texas coral snake (Micrurus fulvius tener) has darker, often maroon, bands with considerable black pigmentation, and the second black band is thick, usually just including the rear of the parietal scales. The range of this species does not overlap that of any other coral snake.
Habitat and Habits: Eastern coral snakes are relatively small animals with a tiny head and fangs, and a small gape. Though it is difficult for the snake to bite and penetrate human skin, they can do so, and especially vulnerable areas are the webbing between fingers and folds of skin at the wrist and thumb joint. The venom is highly toxic, and though many bites may not puncture the skin, all bites should be treated as potential envenomations: It may take 1-8 hours for symptoms to be noticed, so do not postpone seeking medical help.
Symptoms of envenomation may not occur for as much as eight hours after a bite, but are characteristic. Included are dizziness, apprehension, nausea, vomiting, uncontrolled salivation, and a general feeling of weakness. As intoxication progresses, the lower cranial nerves become affected, affecting facial paralysis and loss of feeling, and respiratory inhibition. If not properly treated, coral snake envenomation may cause death from asphyxiation via respiratory failure.
Despite their formidable weaponry, coral snakes are secretive animals that are rarely encountered casually. As burrowing snakes, they are most likely found by non-herpetologists when digging up gardens, breaking up decaying logs, or moving sheet metal or boards that have been lying on the ground. They prefer moist humus and mossy habitats, and frequent rotting logs and piles of leaves where humidity levels are high and prey animals numerous. Some moisture is necessary for coral snakes, and they are common in sandy, well-drained areas in a variety of forested habitats. Coral snakes are diurnal in cool weather, and crepuscular or nocturnal when it is warm. They prefer an air temperature between 82-90º F
The natural diet consists largely of other reptiles, including blind snakes, young burrowing snakes, and skinks, as well as very small mammals (such as newborn shrews and mice), frogs, earthworms, slugs, and large arthropods.
When frightened, coral snakes may form a ball and raise and wave the blunt tail. Presumably, a predator will be distracted by the tail, allowing the snake to make a defensive bite.
Breeding: These snakes are egg layers, but there are few records of captive breedings. The eggs are elongate, oblong and leathery-shelled. Hatchlings are also dangerously venomous.
Special Notes: Coral snakes are deceptively inoffensive animals. This seeming docility, plus their pretty coloring, has led many people to think of them as harmless snakes. This is the typical set-up that leads to snake bite. Young and subadult coral snakes may have difficulty getting their tiny fangs to pierce human skin, but the thin kin between fingers may get punctured. Adult coral snakes (over 25 inches) have little trouble delivering a bite. Unlike pit vipers, which bite quickly and release, coral snakes hang on and use chewing motions to ensure venom delivery. Even a young coral snake can potentially deliver a fatal dose of venom.
Coral snakes are dangerously venomous and have caused human fatalities. They should only be kept by zoos or experienced venomous snake keepers. The venom is a neurotoxin (attacking nerves), and though antivenin is available, a bite is serious and painful. Obviously, these animals are not to be kept as pets.
Dr. Sprackland, author of the forthcomin book GIANT LIZARDS, SECOND EDITION (Fall 2008: TFH Publications), is a herpetologist, science writer, and director of The Virtual Museum of Natural History at http://www.curator.org/.