Eastern Coral Snake Facts

Scientific Name: Micrurus fulvius

Eastern coral snake
Eastern coral snake.

Paul Marcellini / Getty Images

The eastern coral snake (Micrurus fulvius) is a highly venomous snake found in the southeastern United States. Eastern coral snakes are brightly colored with rings of red, black, and yellow scales. Folk rhymes to remember the difference between the coral snake and the nonvenomous king snake (Lampropeltis sp.) include "red on yellow kills a fellow, red on black venom lack" and "red touching black, friend of Jack; red touching yellow, you're a dead fellow." However, these mnemonics are unreliable because of differences between individual snakes and because other species of coral snakes do have adjoining red and black bands.

Fast Facts: Eastern Coral Snake

  • Scientific Name: Micrurus fulvius
  • Common Names: Eastern coral snake, common coral snake, American cobra, harlequin coral snake, thunder-and-lightning snake
  • Basic Animal Group: Reptile
  • Size: 18-30 inches
  • Lifespan: 7 years
  • Diet: Carnivore
  • Habitat: Southeastern United States
  • Population: 100,000
  • Conservation Status: Least Concern

Description

Coral snakes are related to cobras, sea snakes, and mambas (family Elapidae). Like these snakes, they have round pupils and lack heat-sensing pits. Coral snakes have small, fixed fangs.

The eastern coral snake is medium-sized and slender, generally ranging between 18 and 30 inches in length. The longest reported specimen was 48 inches. Mature females are longer than males, but males have longer tails. The snakes have smooth dorsal scales in a colored ring pattern of wide red and black rings separated by narrow yellow rings. Eastern coral snakes always have black heads. The narrow heads are nearly indistinguishable from the tails.

Habitat and Distribution

The eastern coral snake lives in the United States from coastal North Carolina to the tip of Florida and west into eastern Louisiana. The snakes prefer the coastal plains, but also inhabit wooded areas further inland that are subject to seasonal flooding. A few snakes have been documented as far north as Kentucky. Also, there is controversy regarding whether the Texas coral snake (which extends into Mexico) is the same species as the eastern coral snake.

Coral snake species and range in the United States
Coral snake species and range in the United States. HowardMorland, public domain

Diet and Behavior

Eastern coral snakes are carnivores that prey upon frogs, lizards, and snakes (including other coral snakes). The snakes spend most of their time underground, usually venturing out to hunt in the cooler dawn and dusk hours. When a coral snake is threatened, it elevates and curls the tip of its tail and may "fart," releasing gas from its cloaca to startle potential predators. The species is not aggressive.

Reproduction and Offspring

Because the species is so secretive, relatively little is known about coral snake reproduction. Eastern coral snake females lay between 3 and 12 eggs in June that hatch in September. The young range from 7 to 9 inches at birth and are venomous. The life expectancy of wild coral snakes is unknown, but the animal lives about 7 years in captivity.

Conservation Status

The IUCN classifies eastern coral snake conservation status as "least concern." A 2004 survey estimated the adult population at 100,000 snakes. Researchers believe the population is stable or perhaps slowly declining. Threats include motor vehicles, habitat loss and degradation from residential and commercial development, and issues with invasive species. For example, coral snake numbers declined in Alabama when the fire ant was introduced and preyed upon eggs and young snakes.

Venom and Bites

Mexican kingsnake
The Mexican kingsnake is a nonvenomous snake that resembles the eastern coral snake. Paul Starosta, Getty Images

Coral snake venom is a potent neurotoxin. A single snake has enough venom to kill five adults, but the snake cannot deliver all of its venom at once plus envenomation only occurs in about 40% of bites. Even then, bites and fatalities are extremely rare. The most common cause of snakebite comes from mistaking a coral snake for a similarly-colored nonvenomous snake. Only one death has been reported since the antivenin became available in the 1960s (in 2006, confirmed in 2009). Since then, coral snake antivenin production has been discontinued due to lack of profitability.

An eastern coral snake bite may be painless. Symptoms develop between 2 and 13 hours after the bite and include progressive weakness, facial nerve palsy, and respiratory failure. Since antivenin is no longer available, treatment consists of respiratory support, wound care, and antibiotic administration to prevent infection. Pets are more likely than humans to get bitten by coral snakes. They often survive if given prompt veterinary care.

Sources

  • Campbell, Jonathan A.; Lamar, William W. The Venomous Reptiles of the Western Hemisphere. Ithaca and London: Comstock Publishing Associates (2004). ISBN 0-8014-4141-2.
  • Davidson, Terence M. and Jessica Eisner. United States Coral Snakes. Wilderness and Environmental Medicine, 1,38-45 (1996).
  • Derene, Glenn. Why Snakebites Are About to Get a Lot More Deadly. Popular Mechanics (May 10, 2010).
  • Hammerson, G.A. Micrurus fulvius. The IUCN Red List of Threatened Species 2007: e.T64025A12737582. doi:10.2305/IUCN.UK.2007.RLTS.T64025A12737582.en
  • Norris, Robert L.; Pfalzgraf, Robert R.; Laing, Gavin. "Death following coral snake bite in the United States – First documented case (with ELISA confirmation of envenomation) in over 40 years". Toxicon. 53 (6): 693–697 (March 2009). doi:10.1016/j.toxicon.2009.01.032