Green Anacondas

They eat different types of mammals, fishes, caimans, birds and turtles. The snakes at the Vancouver Aquarium primarily get a diet of rabbits, rats and mice.

Green anacondas use both sight and smell to detect their prey. They can also find their prey with special heat sensing pits that border their mouth. Being a powerful constrictor, the anaconda coils its body around its ambushed prey and squeezes until the prey can no longer draw breath.

Like all snakes, green anacondas reproduce sexually and use internal fertilization. Mating typically occurs between April and May. During breeding, the anacondas often cluster in a breeding ball that may consist of 2 - 12 males coiled around one female. The snakes can stay like this for two to four weeks. Green anacondas produce eggs, but the eggs hatch inside the female’s body. The young are then born as miniature snakes. Scientists call this type of birthing ovoviviparous; “ovo” for egg, “vivi” for live and “parous” for bith. Females can give birth from four to 82 young. The longer the female is, the longer the litter size will be. First time mothers have average litter sizes of 10 - 30 young.

To humans, not really: There are few documented attacks by green anacondas on humans. This may be because few people live in places where anacondas are common. There are many myths and stories that depict anacondas as ‘man-eaters’ but anacondas are not ‘man-eaters’ by nature. They are generalists and will take any prey they can subdue and swallow. Large anacondas can capture prey as big as adult capybaras (giant rodents), adult white-tailed deer and full-grown spectacled caimans. These are the same size as a small human (weighing up to 55 kg).

Not really, but the anaconda belongs to the Boidae (Boa) family of snakes and these species are listed in the CITES II appendix. The CITES II appendix lists species which might become endangered if trade is not controlled. Trade in anacondas is prohibited in most South American countries although some are still exported for zoos, research or the pet industry. Few people take anacondas as pets because they grow quite big and are potentially aggressive, although anaconda skins are still traded illegally. These large snakes have very few natural predators because of their size. The main causes of population decline are poaching and habitat destruction.

Boas and pythons are included in the Boidae family, but pythons belong to a subfamily called Pythoninae. The main difference between boas and pythons has to do with their offspring. Boas are ovoviviparous, meaning that the eggs hatch inside the female and the babies are born live. The membrane surrounding the young breaks during birth and allows them to immediately move away from the mother. Pythons are oviparous, meaning that a thin parchment-like shell surrounds the babies. The female lays the eggs and usually incubates them by wrapping her body around the eggs.

Our male green anaconda was born in 1995. He is approximately 3.5 m long. On September 23, 2002, one of our previous anacondas gave birth to 20 young, making the Vancouver Aquarium the first Canadian aquarium or zoo to have a successful anaconda birth. On September 4, 2007, 16 more young were born.