The most common species of the Anaconda genus is the green anaconda (Eunectes murinus). It can be found throughout South America, in the nine countries which share the biodiverse Amazon basin as part of their national territories.
As members of the boa family, all anacondas are non-venomous, relying upon constriction to immobilize and kill their prey. At between 30 and 70 kilograms in weight (66 to 154 pounds), the green anaconda is the world’s heaviest snake, and also one of the longest. Adult females are much larger than adult males, and it is believed that they can grow to more than five meters (16.5 feet) in length. However, because anacondas continue to grow throughout their lives, scientists have not been able to establish precisely their maximum size.
Because of their great bulk, fully grown adult green anacondas have no natural predators, with the exception of other anacondas, although when young or adolescent they can be vulnerable to attack from caimans or jaguars.
Female anacondas have been known to kill and eat their own mates after breeding, as a strategy to help them survive their seven-month pregnancy, during which they do not hunt. Anacondas are polyandrous, with a single female mating with between two and twelve males. During breeding, a so-called “mating ball” is formed, with the mass of males remaining entwined around the female for up to fourteen days.
As its name suggests, this species is green, although it also has black patches along the entire length of its body. The Greek name Eunectes means “good swimmer”, and the mostly nocturnal anaconda hunts in water, preying upon aquatic and semi-aquatic species such as fish, caimans, capybaras and turtles. It has also been known to take down deer and birds. When hunting at night, anacondas can sense the vibration caused by the movement of their prey, and also identify the “chemical signature” of individual species.
The green anaconda is also commonly known as the water boa. The Yacuruna indigenous people of Peru, whose name in the Quechua language means “water people”, call the green anaconda “yacumama”, which means “water mother”. Throughout South America, native peoples have traditionally told their own legends about this giant snake. Among the indigenous people of southern Colombia, the green anaconda is said to be the earthly embodiment of the Milky Way, which after descending to Earth created the Amazon River, from which all humans emerged. For their part, the indigenous people of eastern Ecuador believe that the anaconda guards the entrance to heaven, while for the Jichi of Bolivia it safeguards water sources and is therefore the giver of all life.
In the Tambopata National Reserve and the surrounding forests where we offer our ecotourism activities, including our own Private Conservation Area, green anacondas are often sighted by our naturalist guides and guests, particularly in the rainforest oxbow lakes visited as part of the itineraries we offer.