The Virtual Rainforest
A Neotropical Rainforest
Rainforest Research


Tree Seedlings

Forest Flowers



Army Ants

Bullet Ants
Leafcutter Ants

Rhinoceros Beetle

Swallowtail Butterfly



Keel-billed Toucan

Howler Monkeys

White-faced Monkeys

Three-toed Sloth
Baird's Tapir
White-lipped Peccary
Reptiles and Amphibians:
Red-eyed Tree Frog
Poison Dart Frog
Helmeted Iguana
Eyelash Viper
Terciopelo Viper
Spectacled Caiman
American Crocodile
Human Systems:
Rainforest Boy
Rainforest Girl
Traditional Ecological Knowledge
Rainforest Research

About the Authors





The Big Vipers
Terciopelo aka Fer-de-Lance (Bothrops asper)
Bushmaster (Lachesis muta )

The Terciopelo (Spanish for velvet) Viper is one of the largest and most dangerous venomous snakes in the Neotropical rainforest. The Terciopelo (Bothrops asper; Central America)and Fer-de-Lance (Bothrops atrox; South America) are closely related pit vipers in the family Crotalidae. They reach up to eight feet (2.5 m), with heads up to four inches (10 cm) wide.

These snakes are greatly feared and have many common names. Barba Amarilla (yellow beard) is what larger individuals like this one are often called.

Terciopelos are live-bearers, giving birth to up to 100 young at a time.

Army Ant - Eciton hamatum

Terciopelos are responsible for the majority of venomous snake bites in Central America. Their venom is a hemotoxin, meaning it attacks the blood, and causes clots that lead to death of the surrounding tissues. The bites are very dangerous if not treated with antivenom.

However deadly, these snakes are an important part of the rainforest ecosystem. The favorite food of adult terciopelos are rainforest rats. If these rats become too common, they eat a lot of tree seeds and can change the structure of the forest. The rainforest rats also compete with larger mammals like agoutis.


The other large, venomous snake of the Central American rainforest is the Bushmaster, pictured at right. Although it is also a pit viper, it has many traits that are different. It is the only pit viper species that lays eggs, and unlike most pit vipers, its venom also contains a significant amount of neurotoxin (affects the nerves). The combined hemotoxin-neurotoxin venom is very deadly.

Bushmasters are incredibly rare, perhaps even fewer in number than other top predators like Jaguars and Harpy Eagles. These snakes often reach eight feet in length, with reports of eleven foot (3.4 m) snakes in Central America and fourteen (4.3 m) footers in South America.

Bullet Ant - Paraponera clavata
  Bushmaster photos © Tim Knight. Please visit The Wildlife Web for more amazing photos.


The Virtual Rainforest

Back to the Rainforest

Copyright Gerald R. Urquhart
Michigan State University

Students and teachers have permission to quote text and use images from this website in class assignments. Images may be used in classroom and academic presentations with notification of author. All other use should request permission.


Virtual Rainforest development supported by grant #0815966 from the
National Science Foundation

Center for Global Change and Earth Observation

Michigan State University