Coral snakes are present in Arizona, though encounters are uncommon due to their secretive nature. The species found here is the Western or Arizona Coral Snake (Micruroides euryxanthus), which possesses a highly potent neurotoxic venom. Bites are rare, and fatalities are extremely uncommon in humans due to their small size and specific method of venom delivery. Understanding this species is important for safety in the Sonoran desert ecosystem.
The Arizona Coral Snake: Presence and Range
The Arizona Coral Snake is found primarily across the central and southern parts of the state, extending into southwestern New Mexico and Mexico. This species inhabits a variety of arid and semi-arid landscapes, including desertscrubs, grasslands, and lower mountain slopes. They are typically encountered below 6,000 feet, thriving in rocky drainages, gravelly washes, and areas with loose soil.
This reptile is largely fossorial, spending the majority of its life underground, which explains the rarity of human sightings. They are primarily nocturnal, emerging after sundown to hunt, though they may be active during the day following heavy rains. Their diet consists almost entirely of other small snakes, such as blind snakes and black-headed snakes, along with small lizards.
Identifying the Arizona Coral Snake
Accurate visual identification is necessary for distinguishing the venomous coral snake from its harmless mimics. The Arizona Coral Snake features a distinct tri-color pattern of broad red and black bands separated by narrower bands of bright yellow or white. These bands completely encircle the body, which is a key distinguishing characteristic.
A well-known rhyme is often recited to aid in identification: “Red on yellow, kill a fellow; Red on black, venom lack.” This rhyme is a useful guide since the Arizona Coral Snake’s red bands are bordered by yellow bands. However, relying solely on this rhyme can be dangerous, as some non-venomous snakes, such as the Sonoran Shovel-nosed Snake, can also display red and yellow bands touching.
A more reliable distinguishing feature is the head and snout, which is blunt and black from the nose to just behind the eyes. Harmless mimics, like Kingsnake species, often have a red or light-colored snout and a different arrangement of colored bands. The Arizona Coral Snake is quite slender, typically reaching lengths between 13 and 21 inches, with a head barely wider than its neck.
Understanding the Venom and Bite
The venom of the Arizona Coral Snake is a potent neurotoxin that targets the nervous system by blocking neuromuscular transmission. This action can lead to muscle paralysis and respiratory failure if enough venom is successfully delivered. Unlike pit vipers, which use retractable fangs, the coral snake has short, fixed fangs located in the front of its mouth.
Due to the short fangs and small mouth, a successful envenomation often requires the snake to hold on and perform a “chewing” motion to work the venom into the tissue. This mechanism results in a high number of “dry bites,” where no venom is injected, but all bites must be treated as serious.
A unique characteristic of the coral snake bite is the delayed onset of symptoms, which may not appear for up to 12 hours. Initial symptoms of neurotoxicity include drowsiness, slurred speech, double vision, and generalized muscle weakness. Since the bite site may show minimal pain or swelling, victims might mistakenly believe they were not envenomated. The most severe consequence is the paralysis of the respiratory muscles, necessitating immediate medical intervention.
Safety and Emergency Protocols
Preventative measures significantly reduce the risk of an encounter with this secretive snake. Since they are ground-dwelling and often hide beneath objects, people should avoid turning over rocks, logs, or debris where a snake might be resting. Using a flashlight when walking after dark in desert environments can also help to spot a snake that has emerged from its burrow.
If a bite occurs, the most important step is to remain calm and seek immediate medical attention, even if symptoms are absent. The affected limb should be immobilized and kept below the level of the heart to slow the potential spread of venom. Due to the delayed onset of symptoms, a victim must be monitored in a hospital setting for at least 24 hours.
It is crucial to avoid outdated first-aid methods, such as cutting the wound, applying suction, or using a tourniquet, as these actions are ineffective and can cause further tissue damage. The antivenom for the Eastern and Texas Coral Snakes does not neutralize the venom of the Arizona Coral Snake. Treatment is supportive care focused on managing neurological symptoms and maintaining the patient’s airway and breathing until the neurotoxin effects subside.