The coral snake is a slender, brightly patterned reptile known for its potent, neurotoxic venom and striking coloration of red, yellow, and black bands. Belonging to the Elapidae family, which includes cobras and mambas, the coral snake possesses one of the most toxic venoms of any snake in North America. Though generally reclusive and rarely seen, their presence spans a vast geographic area across the Americas.
Defining the Geographic Range
The distribution of coral snakes across the Americas is expansive, primarily represented by the genus Micrurus. This genus includes over 85 species found throughout Mexico, Central America, and South America, ranging from lowland rainforests to high-altitude cloud forests. Various species occupy nearly every country south of the United States border, extending as far south as Argentina and covering nations like Brazil, Colombia, Costa Rica, and Panama.
Within the United States, the coral snake population is represented by two distinct species with non-overlapping ranges. The Eastern Coral Snake (Micrurus fulvius) is found across the southeastern US, inhabiting a region that stretches from southeastern North Carolina and South Carolina, south through Florida, and westward through Georgia, Alabama, and Mississippi. This species favors the scrub and hammock habitats of the coastal plain, with its range extending to the eastern border of Louisiana.
The Texas Coral Snake (Micrurus tener) occupies a range that includes Texas, western Louisiana, and southeastern Arkansas. Further west, the Sonoran Coral Snake (Micruroides euryxanthus) is the only other species found in the US. This smaller species inhabits central and southern Arizona, extreme southwestern New Mexico, and extends southward into the Mexican state of Sinaloa. Their presence is restricted to the southern and southwestern corners of the country.
Preferred Habitats and Ecological Behavior
Coral snakes are highly secretive reptiles whose habitat preference is defined by environmental features that allow for their subterranean lifestyle. They are classified as fossorial, meaning they spend the majority of their time buried beneath the surface, utilizing loose soil and ground cover for shelter and hunting. Their favored micro-habitats include areas with abundant leaf litter, fallen logs, and loose, sandy soil, such as pine forests and scrub oak sandhills.
This preference for life underground is the primary reason the snakes are rarely encountered by humans, even in densely populated areas within their range. They emerge primarily at night or during the cooler, twilight hours, making them nocturnal or crepuscular in habit. When they do surface, they often use cover objects like rocks, boards, or debris to regulate their body temperature.
Their diet is specialized, consisting mainly of other small reptiles, including other species of snakes and lizards. The neurotoxic venom they produce is highly specialized for quickly incapacitating the nervous systems of these cold-blooded prey items.
Identifying Coral Snakes in Their Environment
The striking pattern of alternating red, yellow, and black bands is the most prominent feature of the coral snake, but this coloration is also mimicked by several harmless species, such as the Scarlet Kingsnake and the Scarlet Snake. Distinguishing the venomous species from its non-venomous look-alikes is a matter of observing the precise arrangement of these color bands. In the United States, a reliable guideline is the famous mnemonic device: “Red touches yellow, kill a fellow; Red touches black, venom lack”.
This rhyme refers to the fact that on a true coral snake, the red bands are always bordered by the yellow bands. Conversely, the harmless mimics have red bands that touch the black bands. Another differentiating feature is that the bands on a coral snake are complete rings that encircle the entire body, whereas the bands on some mimics do not wrap fully around the belly.
A further distinguishing characteristic for both US coral snake species is the head: true coral snakes possess a blunt, black snout that extends past the eyes. However, the color rhyme is not universally accurate, especially for some species in Mexico and Central and South America. Therefore, any banded snake should be left alone without certain identification.