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Biotic Factors of Anacondas

Anacondas are the great constricting boas of South America, occupying similar ecological niches as the pythons of Africa, Asia and Australia. As such, the anaconda interacts with its environment in significant biotic ways. The biggest, the green anaconda, is more massive than any other serpent, although it may be exceeded in length by the reticulated python of Southeast Asia. Mature individuals can reach more than 20 feet long and weigh over 550 lbs. Formidable predators, these snakes suffer from a reputation as highly dangerous to humans, although attacks are rare.

Anacondas as Predators
- The yellow anaconda, while smaller than the green, is still a formidable snake.
  
  Many of the other animals that inhabit the swamps, marshes and flooded savannas favored by large anacondas can fall prey to the huge snakes. A green anaconda feasts on a broad range of creatures, including turtles, waterbirds, white-tailed deer, capybara and caimans. A study on yellow anacondas in the great wetland called the Pantanal -- which sprawls across parts of Brazil, Paraguay and Bolivia -- showed they feed on everything from bird eggs and dead fish to small caimans, although wading birds were the most frequent prey.
Anacondas as Prey
- Jaguars are immensely powerful big cats that occasionally prey on anacondas.
  
  Young anacondas are at risk from a host of predators. These include other reptiles such as the black caiman, a crocodile-like animal that can reach 15 feet long, as well as bigger anacondas. Giant otters, which are large, social aquatic weasels, may also take small anacondas, as will herons, eagles and other big birds. Mature snakes have little to fear from most other animals, but may occasionally fall victim to jaguars, largest of New World big cats and capable reptile-hunters.
Ecological Niche
- The black caiman is an apex predator in some of the same drainages the anaconda frequents.
  
  In a basic sense, anacondas function as secondary consumers: they access the solar energy that drives nearly all life on Earth by feeding on animals that glean it from their own prey or from photosynthetic plants. The green anaconda can also be classified as an apex, or top-level, predator -- one that rests at the top of the food chain and isn't regularly preyed upon by anything else. In the Amazon or Pantanal, the snake would share such a position with other large hunters, including the jaguar, black caiman and puma.
Reproduction
- Green anacondas are well-known for "mating balls," consisting of numerous male snakes encircling a female in an attempt to breed. While the males attempt to push each other away, that seems to be the extent of antagonism between them. Such an aggregation, which typically occurs in April and May, can last for weeks and often transpires underwater or in thick surface vegetation. Female anacondas, like most snakes, are larger than males, and give birth to live young, usually several dozen 2-foot-long offspring that immediately fend for themselves.

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