By Julie Etra
How many ways are there to say “snake” in Spanish? The answer is three (or four, depending on interpretation): serpiente, culebra, víbora (which also refers to vipers, a specific type of snake, including pit vipers), and cascabel, which refers to rattlesnakes. On the Oaxacan coast, we’re home to many snakes. While over 170 species of reptiles exist here—including lizards—this article focuses on two specific snakes: the Tilcoatle (Drymarchon melanurus ssp. erebennus) and the Fer-de-Lance (Bothrops asper). The Tilcoatle is fascinating, while the Fer-de-Lance is equally so but thankfully absent from the Oaxacan coast.
Taxonomy: Understanding the Tilcoatle
The Tilcoatle, also known as the blacktail cribo or middle American indigo snake in English, goes by an impressive variety of names in Spanish: alicante, rey negra (king snake), ratonera negra (black rat killer), culebra arroyera (arroyo snake), babatúa, culebra azul (blue snake), zumbadora (buzzer), culebra prieta (brown snake), culebra negra (black snake), palancacoate, sabanera (savannah dweller), and sayama enjaquimada. Its scientific name originates from Greek: “Drymos” means “forest” and “archon” means “governor,” while “melano” translates to “black” and “urus” means “tail.”
Morphology and Physiology: The Tilcoatle’s Traits
The Tilcoatle is a large snake, measuring an average of 6.5 feet (2 meters) in length as an adult, with some specimens growing up to 3 meters. Its tail constitutes 20% of its overall length. This snake is a visual marvel, with smooth, shiny black scales and an underbelly that can be reddish or yellow. Juveniles often feature faint bands that fade as they mature. While it has teeth and a strong jaw, the Tilcoatle lacks fangs. It is diurnal, meaning it is active during the day, and shelters at night in holes among rocks, rotting roots, or burrows. Breeding occurs annually in winter, with females laying 4–12 eggs under rocks or roots, which hatch in about 80 days. Hatchlings can measure up to 26 inches (66 cm) and reach maturity in two to three years. Their lifespan averages 11 years.
Habitat and Diet: Where the Tilcoatle Thrives
The Tilcoatle is found from the southeastern United States to northern South America. Its adaptability allows it to thrive in various habitats, from forests to deserts. In Mexico, it often inhabits riparian and lacustrine areas and is particularly common around Lake Chapala in Jalisco.An active and voracious predator, the Tilcoatle preys on lizards, bats, rodents, fish, frogs, toads, carrion, and even other snakes, including rattlesnakes and its own species. It has been observed consuming Pituophis deppei (Mexican bull or pine snake) and nauyacas (Fer-de-Lance). The Tilcoatle’s method of predation is unique; rather than venom or constriction, it kills prey by breaking their bones with a powerful bite. Remarkably, its blood is resistant to rattlesnake venom but not to coral snake venom.
Defensive Behavior
Despite its size and predatory capabilities, the Tilcoatle is not aggressive. When threatened, it prefers to flee. Alternatively, it may take a defensive stance by contracting its body and whipping its tail against dry leaves, producing a sound similar to a rattlesnake’s warning. It also emits a foul-smelling odor from its cloaca as a further deterrent.
Myths and Legends Surrounding the Tilcoatle
The Tilcoatle is the subject of numerous myths. One tale suggests that the snake sneaks up on a nursing mother and her baby, sedates them with its breath and tail, and then drinks the mother’s milk, leaving the baby malnourished. Though untrue, this legend is widespread in Mexico, possibly originating in pre-Hispanic times when snakes were revered as deities like Quetzalcoatl, associated with fertility.Other myths claim that the Tilcoatle can deliver a painful whip-like injury with its tail (“chicotazo”). Supposedly, if killed, the snake’s stomach reveals a magical stone that becomes a talisman for the slayer. Some believe the best way to kill a Tilcoatle is by placing a machete upright in the ground so that the snake, striking out, injures itself fatally.Interestingly, the Tilcoatle lends its name to a local cooperative supporting musicians and cultural activities, including free performances at the Mercado Orgánico de Huatulco.
The Fer-de-Lance: A Cautionary Tale
The Fer-de-Lance, known as terciopelo (velvet) in Mexico, is scientifically named Bothrops asper. Its name combines Greek and Latin roots: “Bothros” (“pit”) and “ops” (“face”) refer to its heat-sensing pit organs, while “asper” means “rough.” In French, Fer-de-Lance translates to “spearhead.” This highly venomous pit viper ranges from southern Mexico to northern South America. Unlike the Tilcoatle, the Fer-de-Lance is nocturnal and thrives in moist environments near human habitation, where prey is abundant. Its lifespan is up to 20 years, and females are significantly larger than males.
A Deadly Reputation
The Fer-de-Lance is a dangerous snake with the ability to inject an average of 105 mg of venom per bite; recorded yields go up to 310 mg. As little as 50 mg is enough to kill a human. Its venom causes rapid necrosis, and even with antivenom treatment, survivors often face amputation. Described as unpredictable and excitable, the Fer-de-Lance can move quickly and reverse direction with alarming speed. In Costa Rica, it is responsible for 46% of snake bites and 30% of related hospitalizations. Symptoms of envenomation include severe swelling, bruising, blistering, fever, gastrointestinal bleeding, and even organ failure. Fatalities are often due to sepsis, brain hemorrhage, or kidney failure.
Reducing Fer-de-Lance Fatalities
The Clodomiro Picado Research Institute in Costa Rica has significantly reduced fatalities through antivenom production and venom research. Founded in 1970 by Dr. Clodomiro Picado Twight, the institute plays a vital role in saving lives across Central America.
Moral of the Story
While the Tilcoatle is a fascinating and generally harmless snake deserving of admiration and conservation, the Fer-de-Lance commands respect and caution. Give these creatures the wide berth they deserve, and appreciate them from a safe distance.