Bio Facts: Snake, Eastern Coral
Eastern Coral Snake
Micrurus fulvius fulvius
Southeastern United States and northeastern Mexico
May be found at sea level to 1300 ft (400 km) above sea level in upland mesophytic and tropical hammocks in Florida, as well as glade land, high pine, scrub oak and live oak hammock, Slash Pine and wiregrass flatwoods, dry areas with open ground that are bushy but not heavily vegetated, and associated with sandy ridges and sandy creek bottoms.
Adult length: 31 in. (80 cm); maximum reported length: 51 in. (129.5 cm); appearance: males have longer tails than females, but females reach a greater total length; dorsal scales are smooth in 15 rows; ventral scales number 197-217 in males and 219-233 in females; there are 40-47 subcaudals in males and 30-37 in females; the anal plate is divided; coloration: pattern consists of a series of rings that encircle the body: wide red and black rings separated by narrow yellow rings. The head is black from the rostral to just behind the eyes. The red rings are usually speckled with black. The scales are smooth. The pupil is round. The color pattern of the young is the same as the adults. Fangs are permanent, erect, and hollow proteroglyphous near the front of the maxillae. The venom duct is not attached to the fang directly but enters a small cavity in the gum above the entrance lumen of the gum.
Up to 7 years
Females: 21 – 27 mos.; males: 11 – 21 mos.
In the wild, they eat lizards, frogs and small snakes; in the Zoo, they are fed small rodents and small snakes.
IUCN – Least Concern
M. fulvius is largely a diurnal snake, spending most of the time buried in the soil, in forest areas among decaying logs, leaves, and rocks. It possesses a bimodal activity pattern with more activity from March to May and, again, from August to November. It is solitary except when breeding. It can be aggressive towards its own species but it is otherwise mild mannered.
For defense, it uses color and disruptive patterning: a predator does not know which end is the head or tail, thereby confusing the predator. When threatened, a coral snake often elevates and curls the tip of its tail, swinging it in an attempt to mimic a head; it will also rattle its tail and emit a popping sound with its vent lining.
M. fulvius breeds from late spring to early summer and late summer to early fall. Eggs are laid during May to July. There are approximately 37 days between copulation and oviposition. Clutches of 5-7 eggs will be laid and the young will hatch approximately 60 days later.
New World coral snakes serve as models for their Batesian mimics, false coral snakes, snake species whose venom is less toxic, as well as for many nonvenomous snake species that bear superficial resemblances to them. The role of coral snakes as models for Batesian mimics is supported by research showing that coral snake color patterns deter predators from attacking snake-shaped prey, and that in the absence of coral snakes, species hypothesized to mimic them are indeed attacked more frequently.
The Eastern coral snake has many common names: American cobra, candy stick, common coral snake, coral adder, Elaps harlequin snake, Florida coral snake, garter snake, harlequin coral snake, North American coral snake, red bead snake, thunder-and-lightning snake, candy-stick snake, eastern coralsnake, Florida coralsnake, harlequin coralsnake, and in Spanish serpiente-coralillo arlequín.
M. fulvius does not account for many cases of snakebite in the U.S. because of its secretive nature and general reluctance to bite. In addition, it is estimated that envenomation occurs in only 40% of all bites. But unlike New World pitvipers, this New World coral snake cannot control the amount of primarily neurotoxic venom injected. Dry bites often result from a near miss or deflection, and although the venom an adult coral snake holds is enough to kill 4–5 adult humans, it cannot release all its venom in a single bite. Historically, however, the mortality rate was estimated to be about 10–20%, with death occurring in as little as 1–2 hours, or as much as 26 hours post bite. This is not that surprising, since the LD100 for humans is estimated to be 4–5 mg of dried venom, while the average venom yield is 2–6 mg with a maximum of more than 12 mg. This is probably why it is currently standard hospital procedure in the U.S. to start with antivenin therapy for coral snake bites, even if there are no symptoms yet (since there may not be any noticeable localized symptoms).
Only two documented fatalities were attributed to this species in the 1950s and only one has been reported since Wyeth antivenin became available in the 1960s. The most recent fatality attributed to the eastern coral snake occurred in 2009. The victim failed to seek proper medical attention and died several hours after being bitten, becoming the first fatality caused by M. fulvius in over 40 years.
North American coral snake antivenin belongs to a group of medicines known as immunizing agents. It is used for the treatment of poisoning caused by bites of North American coral snakes, such as the Eastern coral snake, the Texas coral snake, and some other related species of coral snakes. North American coral snake antivenin is to be used only by or under the supervision of a doctor.
A common children’s poem helps distinguish between the venomous coral snake and the harmless mimics, the scarlet snake (Cemophora coccinea) or scarlet kingsnake (Lampropeltis elapsoides): “Red touch black, friend of Jack; Red touch yellow, kill a fellow.” However, this reliably applies only to coral snakes native to North America.
Listed as Least Concern in view of its wide distribution, presumed large population, and because it is unlikely to be declining fast enough to qualify for listing in a more threatened category. Overall, this species does not appear to be significantly threatened. In Alabama, populations declined after introduction of the fire ant, which may prey on eggs and young. Habitat destruction and motorized vehicles are the most serious threats.
Jacksonville Zoo History:
Our first record of an Eastern Coral Snake is 1957 and we have had the species in our animal collection for some part of every decade since then.