Reproduction

How does the green anaconda produce its young?

Breeding season takes place from March to May during the dry season. Female green anacodas move around surprisingly little for this time instead waiting for males to approach them. Many males will approach a single female using a scent trail which they lay down to find her.

On occasion up to 12 males may vie for a single female. These males wrap around the female in what is known as a ‘breeding ball.’ They will then all attempt to mate with the female in a process which may take four weeks before one experiences success.

Female green anacondas may eat their partner after mating which provides the energy she needs during her pregnancy.

This species is capable of giving birth through parthenogenesis. This involves the female fertilizing her own eggs thus meaning she does not need to mate with a male.

Six to seven months after mating the young are born live unlike most snakes which lay eggs. An average clutch contains 20 to 40 anacondas but some have included 100. These young develop inside a membrane which they break out of following birth.

They begin life at 70-80cm (27.5-31.5in) long. Following birth they take off and are responsible for looking after themselves. They generally begin by hiding as they are susceptible to predation.

Until sexual maturity at six years of age a green anaconda will grow rapidly. Growth continues after maturity but at a slower pace.

Behavior

What does the green anaconda do with its day?

Green anacondas are nocturnal. Most of their day is spent in the water. A lot of their time is spent floating with the snout sitting above the water.

In areas where the savanna seasonally floods these snakes will find water or bury themselves in the mud while it is dry. The ones which are buried in the mud enter a period of dormancy.

These animals are able to detect their prey using the tongue which will pick up chemical signals.

Green anacondas are considered solitary and tend to stay alone in their hunting area.

Credit: Public Domain

Predators and Threats

What is impacting the survival of the green anaconda?

As adults green anacondas face no natural predators other than humans but juveniles face a number of predators.

When threatened they may burrow in to mud, escape to the water or roll in to a ball. This protects the head and allows them to retain the ability to strike.

Glands around the cloaca of this snake produce a foul smelling musk which is believed to prevent leeches and ticks attaching in this area.

At present the green anaconda is considered locally common in much of its range but their current population trend has not been determined.

The primary threat to the species appears to be persecution due to their large size.

They are experiencing habitat loss within their aquatic habitat and degradation through the construction of hydroelectric dams. Parts of their range are also used for oil drilling.

In some areas green anacondas have been the victim of vehicle strikes.

Some are captured to be turned in to leather and they may also be used for traditional medicines.

Through much of their range this species is protected by law.

Quick facts

Green anacondas are also referred to as water boas or the common anaconda.

Their scientific name “Eunectes” comes from a Greek word for good swimmer.

A group of green anacondas is known as a bed or a knot.

Green anacondas are a member of the boa constrictor family.

The name anaconda comes from a Tamil word "anaikolra" which meant "elephant killer." These animals were referred to as the "bull killer" by Spanish settlers.