- Animals
- Reference
Green anaconda
- Common Name:
- Green Anaconda
- Scientific Name:
- Eunectes murinus
- Type:
- Reptiles
- Diet:
- Carnivore
- Group Name:
- Bed, knot
- Average Life Span In The Wild:
- 10 years
- Size:
- 20 to 30 feet
- Weight:
- Up to 550 pounds
- IUCN Red List Status:
- Least concern
- Current Population Trend:
- Unknown
What are green anacondas?
A member of the boa family, the green anaconda is the heaviest snake in the world. Its cousin, the reticulated python, can reach slightly greater lengths, but the enormous girth of the anaconda makes it almost twice as heavy.
Green anacondas can grow to more than 29 feet, weigh more than 550 pounds, and measure more than 12 inches in diameter. Females are significantly larger than males.
They are olive in color, with black spots along the length of its body. Black and yellow scales line their bellies. Their eyes and nasal openings are on top of their heads, allowing them to lay in wait for prey while remaining nearly completely submerged.
There are currently three other anaconda species listed by the International Union for Conservation of Nature (IUCN): yellow, dark-spotted, and Bolivian anacondas. All three are from South America and smaller than the green anaconda.
A 2024 study may add a new name to the list. Researchers conducting genetics analysis found that green anacondas are two different types of anaconda that split into these species millions of years ago.
The original southern green anaconda, Eunectes murinus, and the northern green anaconda, Eunectes akayima, are 5.5 percent different, genetically. Humans are, at most, two percent genetically different from chimpanzees.
(Learn more about how scientists discovered the new green anaconda species)
Green anaconda habitat
Anacondas live in swamps, marshes, and slow-moving streams, mainly in the tropical rain forests of the Amazon and Orinoco basins of northern South America.
They are cumbersome on land, but stealthy and sleek in the water. These water hunters can hold their breath for about 10 minutes.
Green anaconda diet and hunting
These boas reach their monumental size by dining on a wide variety of animals, including feral pigs, deer, birds, turtles, capybara, caimans, and even jaguars. They spend most of their time submerged in water waiting for prey, but they can also drop down from trees.
Green anacondas can sense other animals through a few ways. They can pick up scents by flicking their tongues and heat signatures through pit organs in their upper lip. They can also feel vibrations.
Once they find their prey, they use their teeth and strong jaws to lock on. Then, these nonvenomous constrictors coil their muscular bodies around captured prey and squeeze until the animal asphyxiates.
Jaws attached by stretchy ligaments allow them to swallow their prey whole, no matter the size. After a big meal, they can go weeks or months without food.
Reproduction and lifespan
Anacondas are mostly solitary and reach sexual maturity at three or four years. Female anacondas tend to mate every other year, during the dry season from March to May. When they’re ready to mate, females can attract up to 12 males, who fight it out in a “breeding ball.” Sometimes, the female will eat the smallest male.
Females retain their eggs for seven months and give birth to two to three dozen live young in the water. Baby snakes measure about two feet long at birth and can almost immediately swim and hunt. Their lifespan in the wild is about 10 years, but they can live longer in captivity.
Conservation and threats
Although they originated in parts of South America, green anacondas have spread through some Caribbean Islands. They’ve also been spotted in Florida.
According to the Florida Fish and Wildlife Conservation Commission, they are not yet established and encounters are unlikely. However, they are considered an invasive species because of their size, the wide range of animals they might eat, and a lack of natural predators.
The IUCN currently classifies these snakes as species of least concern, when it comes to extinction risk. But this classification relies in part on how widely a species distributes.
The northern green anaconda has a much smaller range than the southern, which means they’re more vulnerable.
Human activity is the biggest threat to anacondas. Humans have caused habitat destruction and hunt the snakes for their skin. Popular movies have depicted green anacondas as people-eating monsters, causing many to fear them.
Frequently asked questions
Anacondas are not naturally friendly toward humans, and it’s illegal to own one in the United States.
They don’t prey on humans and there is no evidence that one has ever eaten a person. However, their size and strength can be lethal against mammals. There is video of an anaconda coiling around a man attempting to wrestle it. —BBC Wildlife Magazine
Do green anacondas live in the U.S.?
Yes, people have reported these snakes in Florida. Most likely, they were pets that escaped their owners. Like the more prevalent Burmese python, anacondas are an invasive species in North America. —U.S. Geological Survey
Are green anacondas aggressive?
Despite their imposing size, green anacondas are not inherently aggressive. However, like all animals, they can become aggressive if provoked. Smaller anacondas tend to be more aggressive than larger ones. —Reptiles of Ecuador
How venomous is the green anaconda?
These reptiles are members of the boa family, so they are not venomous. Green anacondas kill prey by suffocating them or dragging them underwater. —Florida Fish and Wildlife Conservation Commission