Reptiles
Eastern Coral Snake
Micrurus fulvius · also called American cobra, harlequin coral snake
The eastern coral snake is a small, brightly banded, highly venomous relative of the cobra that lives across the southeastern United States. Despite carrying one of the most toxic venoms on the continent, it is among the least likely snakes to ever bite a person — it is shy, secretive, and spends most of its life out of sight.
Overview
Eastern coral snakes inhabit pine flatwoods, sandhills, hardwood hammocks, and scrub with loose, sandy, well-drained soil across the US Southeast. They are fossorial and secretive, spending the bulk of their time burrowed into soil, leaf litter, and decaying wood, and surfacing mainly in the cool of morning and evening and after rain. Even herpetologists consider a coral snake sighting a lucky event.
Warning colours and mimics
The coral snake’s rings of red, yellow (or cream), and black are classic aposematic colouration — a warning that the animal is dangerous. Several harmless snakes, especially the scarlet kingsnake and scarlet snake, have evolved similar banding to borrow that protection (Batesian mimicry). In the US the patterns can be told apart:
- Coral snake: red and yellow bands touch; snout black. (“Red touches yellow, kill a fellow.”)
- Mimics: red and black bands touch; snout red. (“Red touches black, venom lack.”)
This rhyme is dependable only for the North American species; tropical coral snakes break it freely.
Venom and bites
Coral snake venom is a potent neurotoxin in the same family as cobra venom, capable of causing paralysis. But the snake is poorly equipped to deliver it to large animals: it has a small mouth and short, fixed fangs, and it tends to hold on and chew rather than strike and release. Bites on humans are extremely rare — well under 1% of US venomous snakebites — almost always involve deliberate handling, and, since antivenom, none has been fatal. Symptoms can be delayed for many hours, so any suspected bite is treated as an emergency.
Diet and reproduction
Coral snakes are snake and lizard specialists, hunting by scent through the leaf litter and swallowing prey — often nearly as long as themselves — head-first. Unlike the live-bearing pit vipers of the region, the eastern coral snake lays eggs, a small clutch of three to a dozen, in summer; the young hatch fully venomous and independent.
Status
The eastern coral snake is listed as Least Concern and remains widespread, though its secretive habits make population trends hard to judge. Localised declines are linked to the loss and fragmentation of the longleaf pine and sandhill habitats it shares with the eastern diamondback rattlesnake and gopher tortoise, along with road mortality and killing on sight by people who mistake it — or its harmless mimics — for a threat.
Eastern Coral Snake: common questions
How do you tell a coral snake from a harmless mimic?
In the United States, the rhyme "red touches yellow, kill a fellow; red touches black, venom lack" works. On a true eastern coral snake the red and yellow rings touch each other, and the snout is black. On the harmless scarlet kingsnake and scarlet snake that mimic it, red rings touch black rings, and the snout is red. The rule is reliable for the US species but does not hold for the many coral snakes of Central and South America, some of which have completely different patterns.
How dangerous is an eastern coral snake bite?
The venom is extremely potent — a neurotoxin that can cause slurred speech, double vision, muscle weakness, and, in severe untreated cases, respiratory paralysis, sometimes many hours after the bite. But actual bites are very rare. Coral snakes are shy, reluctant to bite, and have small mouths and short fixed fangs, so they usually cannot get a good grip on anything larger than a finger or a fold of skin. There has been no confirmed death from an eastern coral snake bite in the US since antivenom became available in the 1960s.
Why is the eastern coral snake so rarely seen?
It is a secretive, fossorial animal — it spends most of its time buried in loose soil, leaf litter, and rotting logs, or under debris, hunting for the small snakes and lizards that make up its diet. It is most active in the early morning and evening and after rain, and even in areas where it is common, people may live for years without encountering one.
Is the coral snake related to cobras?
Yes. Coral snakes belong to the family Elapidae, the same group as cobras, mambas, kraits, taipans, and sea snakes, all of which have fixed front fangs and largely neurotoxic venom. This is why the eastern coral snake is sometimes called the "American cobra." It is only distantly related to the vipers — rattlesnakes, copperheads, cottonmouths — that account for nearly all other US venomous snakebites.