Snakes of the Yasuni

The Snakes of the Yasuni Biosphere Reserve have covered every niche the forest has created from the canopy to the ground, inside soil, inside water. If you are walking through and spot a whip snakes resting on dead branches across the your path, is a signal of the forest is always in motion, sometimes canoeing along rivers or oxbow lakes and catch sight of a giant anaconda coiled, you cannot help but feel excited.

We will talk about some of Snakes of the Yasuni,  encountered  while exploring the terra firme, varzea, moriche swamps, forest streams and forest swamps.


Anacondas are the world’s heaviest snake at around 250 kg. They grow to about 10 metres and lead a semi-aquatic lifestyle made possible by the position of their eyes and nostrils on the tops of their head. They seem to choose areas with thick vegetation (grassy areas ), pile of dead logs where they hide. They hunt mainly at night eating most manageable animals like capybara, peccaries and deer.

Amazon Whip Snake

Snakes in this genus (Chironius) are among the most abundant in all South American forests. They include both ground-living and canopy-living diurnal species that mainly prey on frogs but also take lizards and birds.

Chironius seeks prey in shrubs and trees. Smart for a snake, there are records of this species investigating bromeliads for their frog prey. Bromeliads collects water making a perfect home for frogs.


Bushmasters are a formidable South American viper and are the largest venomous snake in the western hemisphere. Bushmaster is a very large snake, often exceeding 6,5 ft (2 m) in length. But they can grow to be over 12 ft (3.5 m) making them the longest venomous snake found in the Americas. Strangely for a neotropical pitviper, bushmasters lays eggs as opposed to giving birth to live young.

Fer-de lance

Fer-de lance are nocturnal and solitary. It can be found near rivers and streams, basking under the sun during the day and lying still while well camouflaged in leaf litter or under forest cover waiting to ambush prey (including rats and mice) that comes within range during the night. When cornered or threatened, this species can be very defensive and may exhibit an S-coiled defense display. Juveniles are often semi arboreal and even adults are sometimes encountered in bushes and low trees.

Emerald Tree Boa

Emerald tree boas live in the trees and blend into the leafy background. They often use their strength to hang from branches and snatch prey like mammals and birds. They have white markings over their body and are locally common in the Amazon Rainforest. Juveniles of this species are reddish orange then mature to a magnificent green.

Rainbow Boa

Rainbow Boas have iridescent scales -it shines at any direction or angle- giving this boa its common name. They feed on birds, lizards, and small mammals found in their range of northern and central South America. Can be found inside leafcutter ants colonies. Rainbow boas are very popular in the pet trade due to their beautiful colouration.

Boa Constrictor
Boa constrictors are a very distinct snake. Their colouration depends on habitat and there are many different subspecies. Although proficient swimmers, they prefer a more land-based lifestyle and seek safety in mammal constructed burrows. Constrictors are dwarfed by their anaconda cousins and grow to around 4 metres in length. Threatening their existence in the wild, boas are hunted for their skins to make various products.

Coral Snake
The South American coral snake is a beautifully patterned elapid (member of the Cobra (Elapidae) family. Coral snakes vary widely in their behavior, but most are very elusive, fossorial snakes which spend the vast majority of their time buried beneath the ground or in the leaf litter of a rainforest floor, coming to the surface only when it rains or during breeding season. Some species, like Micrurus surinamensis, are almost entirely aquatic and spend most of their lives in slow-moving bodies of water that have dense vegetation. Coral snakes feed on lizards and other snakes and are highly venomous.

Amazon Tree Boa
As their name suggests, Amazon Tree Boas live mainly in the trees and are classed as arboreal, but they can come down to the ground at night. Like the emerald tree boas, these snakes are also known to hang from trees to catch passing prey. They have varied colouration from an olive body to orange or yellow.