Class: Reptilia (Reptiles)
Size: longest—reticulated python Python reticulatus, up to 33 feet (10 meters); shortest—ant-hill python Antaresia perthensis, about 23 inches (60 centimeters)
Weight: heaviest—reticulated python, up to 250 pounds (113 kilograms)
Life span: up to 35 years
Number of eggs laid: 2 to 100, depending on species
Incubation: 40 to 100 days, depending on species
Size at hatching: 10 to 27 inches (25 to 70 centimeters)
Age of maturity: 2 to 8 years
Conservation status: woma Aspidites ramsayi and Indian rock python Python molurus molurus are endangered, most other pythons are becoming more rare due to the trade in snake skins and habitat destruction.
pythons have been seen swimming in the ocean, which is probably
how they originally got to the islands in the Pacific Ocean where
some of them live.
Pythons have four rows of back-curving teeth in their upper jaw and two rows of teeth in the lower jaw that they use for obtaining, holding, and moving prey back into the esophagus.
Listen to a python!
Because reticulated pythons, boa constrictors, and anacondas are some of the biggest snakes in the world, many people get confused about which is which.
The first thing to note is that the anaconda is a species of boa, not a separate type of snake. That leaves two groups, the pythons and the boas. These snakes are both constrictors, killing their prey by wrapping around it and suffocating it. And they are both considered primitive snakes with two lungs (most snakes only have one) and the remnants of hind legs and pelvic bones. But they have differences, too.
Pythons have one more bone in their heads than boas do and some additional teeth. And pythons are mostly found in the Old World (Africa, Asia, Australia) while boas live in both the Old World and the New World (North, Central, and South America). But the biggest difference is that pythons lay eggs while boas give birth to live young.
Pythons are constrictors. They grab their prey with their teeth, then quickly wrap coils of their bodies around the prey and squeeze. They don’t actually crush the prey and break its bones, though. Instead, they squeeze tightly so that the prey animal can’t breath and it suffocates. The snake then begins the leisurely process of unhinging its jaw and swallowing the prey whole, usually head first. This is accomplished with rhythmic muscular contractions that pull the prey down the snake’s throat and into its stomach. How does the snake breathe while its mouth is full? It has a special tube in the bottom of its mouth that stays open to one side to take in air.
Do pythons have predators?
Yes, they do. Small, young pythons may be attacked and eaten by a variety of birds, carnivorous mammals, large frogs, large insects and spiders, and even other snakes. But adult pythons are also at risk from birds of prey like eagles and even lions and leopards.
Feeling the heat
Like most snakes, pythons don’t chase after their prey. Instead they are ambush hunters. They use both sight and smell to locate prey. Pythons also have an additional advantage: most have special temperature-sensitive "pits,” or holes, along their jaws that can sense the heat of a nearby animal. This helps them find prey even in the dark or among dense foliage. Depending on the size of the snake, pythons may eat rodents, birds, lizards, and mammals like monkeys, pigs, or antelope. One rock python Python sebae was even found to have a small leopard in its stomach. At the San Diego Zoo, our pythons eat thawed rodents and rabbits.
Unlike their close relatives the boas, pythons lay eggs. Some species lay them in a shallow nest or even cover them with leaves and soil. But what’s really remarkable is that most python mothers stay coiled around their eggs to protect them while they develop, and if the temperature gets too cold, the mothers of larger species warm their eggs up by "shivering.” This involves rhythmic contractions of the muscles and is described as looking like the snake has the hiccups. Even though snakes are ectothermic, the mother python can, amazingly, raise the temperature of her eggs up a few degrees by doing this. It takes a lot of energy, though, so she may not reproduce again for two to three years as she gains back the weight she lost. After the eggs hatch, she leaves and the babies are on their own.
Because of their bulk, pythons move by traveling forward in a straight line, which is known as "rectilinear progression.” This is accomplished by stiffening the ribs to provide support, then lifting a set of ventral (on the belly) scales and moving them forward so the loose ends grip the surface, pushing the snake ahead. This type of movement works on the ground as well as in trees. They can’t move very fast though—only about 1 mile per hour (1.6 kilometers per hour) on open ground. But since they don’t have to chase their food, they don’t really need to move quickly.
Swimmers, not divers
Some people think that pythons launch themselves out of trees onto unsuspecting animals below. That’s not something a python would want to do. Diving out of a tree like that could cause serious injury to the snake, especially a big one. In fact, most big pythons stay on the ground for that very reason. Swimming is another story! Many pythons are excellent swimmers and spend a lot of time in the water. One of their ambush techniques to catch food is to lie submerged in a stream or slow-moving river with only their heads above the water, waiting for a bird or small mammal to come to the water’s edge.