Living in tropical South America, anacondas are apex predators and some of the largest and heaviest snakes in the world. They are a semi-aquatic species and prefer going after large prey, both on land and in the water. Their muscular bodies are strong enough to squeeze the life out of deer, tapirs, capybaras, and even aquatic reptiles like caimans. But how strong are anacondas actually?
Anacondas have a constriction force of about 90 PSI, which is the rough equivalent of a 9,000-pound school bus sitting on your chest. They also have powerful jaws compared to other snakes, with an estimated bite force of 900 PSI. However, anacondas don’t use their bite force to kill prey. They kill through constriction, cutting off the prey’s blood supply.
Anaconda Species Strength Facts:
- Adult anaconda bite force: 900 PSI
- Anaconda constriction force: 90 PSI
- Adult anaconda length: 20 to 30 feet
- Adult anaconda weight: up to 550 pounds
- Anaconda speed on land: 5 mph
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How Strong Are Anacondas?
Anacondas are the largest snakes in the world by weight and also the strongest predatory constrictors. Scientifically, anacondas belong to the same family as boas and are even called water boas due to their habitat – they inhabit South America’s rain forests and wetlands.
As predatory constrictors, anacondas don’t have powerful jaws compared to other big reptiles, such as the alligators or caimans. However, they have an incredible squeeze power of about 90 PSI. This is about six and a half times the squeeze force of a python and over 30 times the hand squeeze force of a human.
Not all anacondas are this strong, though. These snakes use their muscular bodies to generate force. Thus, the smaller the snake, the lower the force it can exert.
There are four types of anacondas, with green anacondas being the largest and most powerful. Yellow anacondas and Bolivian anacondas are smaller, while the dark-spotted anacondas are the smallest.
The table below highlights the length and weight differences between the various anaconda subspecies:
| Subspecies | Avg. length | Avg. weight |
|---|---|---|
| Green anaconda | 20 feet | 330 lbs. |
| Yellow anaconda | 13 feet | 100 lbs. |
| Bolivian anaconda | 12 feet | 80 lbs. |
| Dark-spotted anaconda | 9 feet | 70 lbs. |
Note: The sizes and weights above are averages based on the most common smaller and larger snake sizes. Some of the largest anacondas can exceed 30 feet in length and weigh over 500 pounds. It should also be noted that anacondas are sexually dimorphic, with females larger and heavier than males.
How Strong Is An Anaconda’s Bite?
Anacondas don’t have very powerful bites compared to most apex predators (including mammals and other big reptiles), but they can still allegedly exert a jaw force of about 900 PSI.
While experts have only estimated the bite force of an anaconda based on its jaw morphology, these snakes rarely use their mouths to kill prey. As predatory constrictors, anacondas use their muscular bodies to cut off the victim’s blood supply, then swallow their victims whole.
In the rare attacks of anacondas on humans, it was also observed that these snakes didn’t inflict life-threatening injuries through bite alone. Thus, while an anaconda’s bite is undeniably hurtful, we can assume that the small teeth and jaw morphology make it hard for the snake to bite at full force.
In fact, unlike mammals and other reptiles, anacondas don’t have rigid jaws. Instead, each of their jaws (lower and upper) consists of two sides connected by an elastic ligament, while the joint between the upper and lower jaw pivots to allow for a vertical and horizontal rotation.
This morphology allows the snake to move each side of the jaw independently and open its mouth wide enough to swallow its prey whole, regardless of the prey’s size.
Thus, it is safe to conclude that anacondas could exert a bite force of 900 PSI, but their actual bite force is much lower than that.
Squeeze Force
If anacondas don’t have the strongest bites, they definitely have an outstanding squeeze force. In a test, experts found that the constriction force of an anaconda can exceed 90 PSI. This is about as much as a 9,000-pound school bus pressing on your chest.
To understand how strong anacondas truly are, know that the average human can resist a squeezing force of about 50 PSI, if applied gradually, and the average hand squeeze of a human is about 2.37 PSI.
Not only are anacondas much stronger than humans, but they are also stronger than other predatory constrictors, such as the pythons.
In fact, an 18-foot python can only create a squeeze force of about 14.22 PSI, which is about six times the hand squeeze force of a human. By comparison, anacondas are over six times stronger than pythons and about 37 times stronger than a human.
The video below explains more about an anaconda’s constriction force:
https://www.youtube.com/watch?v=ja3Q9ZwWfec
Movement Speed
Like all snakes, anacondas slither on the ground, but that doesn’t mean they are slow. In fact, they can reach speeds up to five miles per hour on land. Anacondas are also good swimmers, reaching speeds up to ten miles per hour in the water.
By comparison, the average human can reach top speeds of about 8 miles per hour when running – which could be your only advantage when faced with a starving anaconda.
Although an anaconda’s speed on land is slower than other apex predators, they are fast by snake standards. Moreover, anacondas can move much faster in short bursts, striking the prey, latching onto it, and completely coiling their bodies around it in about ten seconds.
This leaves most animals that fell into the snake’s deadly grip with little to no chances of striking back or escaping the predator.
Typically, anacondas wrap themselves around a prey’s upper body, and often latch onto their necks, pressing on the jugular vein. This is because anacondas don’t suffocate their prey but apply pressure on the chest to cut off the blood supply to the heart and ensure a faster kill.
Observations also show that these snakes keep squeezing the prey much longer than necessary – sometimes up to 15 minutes. This is enough time to ensure that the prey is dead and will not fight back once the anaconda loosens its grip.
Are Anacondas Stronger Than Humans?
Anacondas have a constriction force stronger than all other snakes. They are not only much stronger than humans, but they are stronger than all other animals, including powerful beasts like the caimans. Anacondas could even kill and feed on other apex predators like the jaguars.
This is where some questions arise. Can anacondas break bones? Can a human fight off an anaconda?
Although an anaconda’s purpose isn’t that of breaking bones when squeezing the prey, the pressure exerted on the victim’s body can definitely break its bones. Think of it as being squeezed under a bus – the high force would break your bones.
Anacondas are much stronger than humans, and they move incredibly fast when striking. While attacks on humans are rare, your only chance of fighting off the snake would be to catch its head and squeeze onto its neck with all your force or poke its eyes, determining it to uncoil from around your body.
However, if the anaconda manages to coil around your arms before you manage to grab its head or neck, the chances of fighting it off on your own are slim.
For this reason, it is always recommended to keep your distance from anacondas and run as fast as you can if you happen to see an anaconda on land – humans usually run faster than an anaconda can slither. If you’re in the water, your best bet is to frighten the snake if possible or try to grip its head, poke it in the eyes, or even bite its tail to fight it off.