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Terciopelo (Fer-de-Lance Snake): Characteristics, Diet, Facts & More [Fact Sheet]

The Fer-de-Lance or Terciopelo, known scientifically as Bothrops asper, is a formidable and widely recognized snake species native to Central and South America. Renowned for its potent venom and agility, this species is both respected and feared.

As a member of the pit viper family, the Fer-de-Lance embodies the perfect blend of evolutionary adaptation and ecological significance, playing a crucial role in its habitat as a top predator.

This article aims to provide an insightful overview of the Terciopelo, exploring its classification, physical characteristics, behavior, and ecological impact, offering a window into the life of one of the most intriguing snake species in the Americas.

The Terciopelo at a Glance


Class:Reptilia (Reptiles)
Species:B. asper

Essential Information

Average Size:Length: 1.2-1.8 meters (4-6 feet), occasionally larger
Average Weight:1.5-2 kg (3.3-4.4 lbs)
Average Lifespan:Around 10-20 years in the wild
Geographical Range:Central and South America, from southern Mexico to northern South America
Conservation Status:Least Concern (IUCN Red List)

Species and Subspecies

The Fer-de-Lance or Terciopelo, scientifically known as Bothrops asper, is a highly venomous pit viper with no currently recognized subspecies. It’s one of the largest and most formidable pit vipers, both in size and venom potency.

The Terciopelo is found in various regions, from northeast Mexico and Central America to South America, including elevations up to 2600 meters in the Colombian and Ecuadorian Andes, as well as Venezuela.

This species can reach a massive size, with individuals weighing up to 6 kilograms (13 lbs) and growing up to 2.5 meters (8.2 feet) in length. The Terciopelo is characterized by its light to dark brown coloration, often adorned with yellow zig-zag-shaped lines on each side of the body.

The Terciopelo, also known as the fer-de-lance among several other local names, has a reputation for being “the ultimate pit-viper.” It is responsible for the most snakebites within its range, due to its defensive temperament and proximity to human residences. Despite this, like other venomous snakes, it generally avoids confrontation with humans.

The name “fer-de-lance” is French, translating to “iron of the lance” or “spearhead”, and is used to refer to various species within the genus Bothrops. However, the term “terciopelo” is now preferred by herpetologists for Bothrops asper. The specific epithet, asper, meaning ‘rough’ or ‘harsh’ in Latin, may allude to the species’ keeled dorsal scales.

Fer de Lance


The Terciopelo, or Bothrops asper, is a robust and powerful snake, renowned for its size and potent venom. Adults typically reach lengths of 1.2 to 2.5 meters (4 to 8.2 feet), making them one of the largest pit vipers.

They can weigh up to 6 kilograms (13 lbs), which is substantial for a snake. Their coloration is generally light to dark brown, providing excellent camouflage in their natural habitat, and is marked by distinctive yellow zig-zag-shaped lines along the body.

A defining characteristic of the Terciopelo is its broad, triangular head, which houses the heat-sensitive pit organs used for detecting warm-blooded prey. The dorsal scales are keeled, giving them a rough texture, as indicated by the Latin name ‘asper’. This species also possesses long, hinged fangs capable of delivering a large volume of venom.

Sexual dimorphism in Terciopelos is not particularly pronounced, though females are generally larger and heavier than males, which is typical of many viper species.

Habitat and Distribution

The Terciopelo is found at low to moderate elevations in northeast Mexico, throughout Central America, and into South America. Their range extends to the Colombian and Ecuadorian Andes and into Venezuela, inhabiting elevations up to 2600 meters.

They thrive in a variety of habitats, including tropical rainforests, dry forests, and even cultivated areas like plantations, often bringing them into close proximity with humans.

Fer de Lance


Terciopelos are primarily nocturnal, hunting and being most active during the night. They are known for their defensive temperament and will often stand their ground or strike if they feel threatened. This behavior, combined with their tendency to inhabit areas near human activity, contributes to their reputation for being involved in many snakebite incidents.

These snakes are generally solitary, except during mating periods. They rely heavily on their heat-sensing pit organs for hunting, allowing them to detect and accurately strike warm-blooded prey even in complete darkness.

Communication in Terciopelos is not well documented but, like other snakes, they likely use pheromones for signaling during mating seasons and may exhibit body language as a form of defensive communication.

Diet and Feeding Behavior

The Terciopelo is a carnivorous predator, primarily feeding on small mammals like rodents, as well as birds, lizards, and amphibians. Their hunting strategy is characterized by ambushing prey, using their camouflage to remain hidden until a potential meal comes within striking distance. Their heat-sensing pit organs play a crucial role in detecting warm-blooded prey, even in low visibility conditions.

Once the prey is within range, the Terciopelo strikes quickly, injecting a potent hemotoxic venom that immobilizes and begins to digest the prey internally. The snake then locates and swallows its prey whole. The efficiency of their hunting technique makes them successful predators in their environments.


While adult Terciopelos have few natural predators due to their size, venom, and aggressive nature, they are at risk from larger predators when they are younger and smaller.

Potential predators include large birds of prey, such as eagles and hawks, as well as other larger snakes and mammals. Their cryptic coloration helps to protect them from these threats.

Fer de Lance

Reproduction and Life Cycle

Terciopelos are oviparous, meaning they give birth to live young. Breeding occurs annually, and during the mating season, males may engage in combat dances to compete for females. These dances involve intertwining their bodies and trying to subdue each other.

The gestation period for the Terciopelo is approximately six to seven months. During this time, the female carries the developing embryos internally until they are ready to be born.

A female Terciopelo can give birth to a large number of young, sometimes up to 60 in a single litter, although the average is usually around 20 to 30. The newborn snakes are independent from birth and are equipped with venom and fangs, enabling them to fend for themselves and start hunting almost immediately. The mother provides no parental care after birth.

Conservation and Threats

The Terciopelo, or Bothrops asper, is not currently listed as a threatened or endangered species. It is relatively widespread and common within its geographical range. However, like many wildlife species, it faces general threats from habitat destruction and environmental changes.

Habitat loss due to agricultural expansion, deforestation, and urban development poses a threat to the Terciopelo’s natural habitat. Additionally, they are often killed on sight by humans due to their reputation as dangerous snakes, which can locally impact their populations.

Conservation efforts for the Terciopelo mainly involve habitat preservation and educating local populations about the snake’s ecological role and how to coexist safely with them. Research on their ecology and behavior also contributes to the understanding and conservation of this species.

Fun Facts

  1. Impressive Venom: The Terciopelo’s venom is not only potent but also abundant; it can deliver large amounts of venom in a single bite.
  2. Resilient Survivors: These snakes can thrive in a variety of environments, from dense rainforests to agricultural areas.
  3. Long Fangs: The Terciopelo has some of the longest fangs of any viper, reaching lengths of up to 2.5 cm (1 inch).
  4. Cultural Significance: In many cultures within its range, the Terciopelo is a subject of folklore and often respected as a powerful force in nature.
  5. Speedy Striker: Known for its lightning-fast strike, the Terciopelo can strike and return to its coiled position in a fraction of a second.

Frequently Asked Questions

How dangerous is the Terciopelo to humans?

The Terciopelo is considered one of the most dangerous snakes in its range due to its potent venom, tendency to inhabit areas near humans, and defensive nature. However, fatalities are rare with prompt and appropriate medical treatment.

What should I do if I encounter a Terciopelo in the wild?

If you encounter a Terciopelo, maintain a safe distance and do not attempt to touch or move it. Slowly back away and give the snake space to retreat.

Can Terciopelos swim?

Yes, like many snakes, Terciopelos are capable swimmers and can be found near water sources.

How can Terciopelos be identified?

Terciopelos can be identified by their large size, distinctive brown color with yellow zig-zag patterns, large triangular head, and notably long fangs.

What is the natural diet of the Terciopelo?

The Terciopelo primarily feeds on small mammals, birds, and occasionally amphibians and reptiles.

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