Anacondas are solitary animals except in the breeding season, which can last as long as six months. Most of their time is spent in an aquatic environment. They venture onto dry land for mating, but also when moving from one body of water to another. Occasionally they’ll hunt on land. Anacondas do not seem to be territorial.
Around the mouth, anacondas have thermal depressions that are sensitive to infrared radiation (heat). These allow them to perceive the presence of warm-blooded animals (like mammals) in the dark.
The anaconda has rather mediocre hearing. On the other hand, it can capture vibrations through its jaws, which enable it, for example, to detect the movements of a mouse walking on a tree trunk lying on the ground. The anaconda therefore analyzes its environment thanks to its eyes, its forked tongue (which is connected to its Jacobson’s organ, highly sensitive to smells/taste), its thermal dimples and its jaws. It often remains immobile for hours, camouflaged in the water or in trees, making it invisible to prey that get close to it.
As is the case with all snakes, its tongue is forked: the end of it is divided in two. At the tip there are numerous little sensors that retain the smells released by prey. Inside the mouth, there are two small pits sensitive to the smells at the back of the palate: this is the vomeronasal organ, or Jacobson’s organ.
When the tongue enters the mouth, each tip positions itself close to the pits, which will then perceive the smell. If the prey is located to the right, the right part of the tip of the tongue will carry more of the smell, and the right pit will be more stimulated than the one on the left. The anaconda then knows that its prey is on the right side. By moving its tongue continually in and out, the reptile will know at all times what’s going on around it and pursue its victim without any problem.
The yellow anaconda also possesses heat-sensitive pits that are located on the edge of the upper jaw, between the eyes and the nostrils. Those pits are sensitive to subtle variations in temperature. At the back of these there are receptors that capture the heat emitted by prey. It’s in analyzing that heat, from the left or from the right, that the reptile discovers where its prey is located. It can even follow the still warm trail of drops of urine left by a small rodent (like a mouse) when it moves!
To eat very large prey like capybaras or deer, the yellow anaconda, like all snakes, has special adaptations. First of all, it can dislocate its jaw. The two jawbones come apart, which makes it possible for the mouth to open very wide. In addition, the lower jaw is composed of two parts that are not welded together. These two sections can therefore move aside to let the prey pass through. Once the prey is ingested, ligaments, which act like elastics, will bring these two parts back together and reassemble the lower jaw.
The yellow anaconda haunts mostly at night. Its preferred hunting territory is the aquatic environment. It can stay underwater for close ten. Its slender face, its long and extended shape and the fact that its scales are very smooth allow it to glide easily under water. To protect them from aquatic debris, the anaconda’s eyes are covered by a transparent scale.
According to several scientists, anacondas do not make good pets. They grow quickly, their cage becomes too small and the snakes then become dangerous both for other pets and for humans. They have an aggressive temperament and will never become animals that are easy to handle. What is worse, when they’re disturbed they release a foul, repugnant musk. Many of these pet snakes are the result of poaching and illegal harvesting. Activities that are possibly temporarily useful for the local economy but that impoverish biodiversity forever.