The green anaconda is one of the largest snakes in existence, growing up to 30 feet (9 m) long and weighing more than 500 pounds (227 kg), though the average size is about 17 feet (5 m). Like the python and boa constrictor, these non-venomous snakes kill by squeezing, crushing and sometimes drowning their prey. They live in the rivers and streams of remote regions of several South American countries, including Brazil, Venezuela, Columbia, Ecuador and Peru. The Latin name for this species is Eunectes murinus, which means "good swimmer who preys on mice."
These types of snakes are identified by their drab green color with splotches of black covering the full length of their thick, shiny bodies. Their narrow heads have yellow or red striping on each side, and high set eyes that allow good vision while immersed in water with only the tops of their heads above the surface. Their nasal cavities also are on top of their heads; this allows them to breathe while remaining unseen in the water, which is where they spend most of their lives. Green anacondas are also good climbers and can frequently be found hanging from trees above the water, waiting to drop on their prey.
These snakes spend much of their time in the water, so the majority of their diet is found there. They prey on fish, water birds, other reptiles, and even smaller anacondas. When on land, the green anaconda can take down large animals such as deer and jaguars, though this does not happen frequently. They are much more likely to go in search of an easier meal in or near the water. The green anaconda eats only infrequently and can go as long as a year after a large meal before needing to eat again.
The green anaconda is a solitary creature and goes in search of others only during mating season. This is during the rainy season in South America and lasts for most of the spring. Male snakes may travel quite far in search of the much larger females, and several males may end up locating the same female snake. The result is what is known as a breeding ball, where many males are wrapped around one female in an attempt to breed with her.
The female does not eat in the six or seven months it takes for baby green anacondas to incubate. The mother produces eggs that hatch while still inside the body, and she gives birth to a litter of about 30 to 40 live babies, though litters of as many as 100 have been recorded. The babies are on their own from birth, receiving no care from their mother. As a result, many of them do not survive for long, becoming prey for many types of animals.