Photo: Close-up of a boa constrictor's head

As their name suggests, boa constrictors slowly squeeze their prey to death.

Photograph by Joel Sartore

Map

Map: Boa constrictor range

Boa Constrictor Range

Fast Facts

Type:
Reptile
Diet:
Carnivore
Average life span in the wild:
20 to 30 years
Size:
13 ft (4 m)
Weight:
60 lbs (27 kg)
Group name:
Bed or knot
Did you know?
Some South Americans keep boas in their houses to control rat infestations.
Size relative to a 6-ft (2-m) man:
Illustration: Boa constrictor compared with adult man

Boa constrictors wear some of the most distinctive markings of all reptiles. Depending on the habitat they are trying to blend into, their bodies can be tan, green, red, or yellow, and display cryptic patterns of jagged lines, ovals, diamonds, and circles.

Boas are nonpoisonous constrictors found in tropical Central and South America. Like their anaconda cousins, they are excellent swimmers, but prefer to stay on dry land, living primarily in hollow logs and abandoned mammal burrows.

Significantly smaller than anacondas, boas can grow up to 13 feet (4 meters) long and weigh more than 100 pounds (45 kilograms). Their jaws are lined with small, hooked teeth for grabbing and holding prey while they wrap their muscular bodies around their victim, squeezing until it suffocates. Boas will eat almost anything they can catch, including birds, monkeys, and wild pigs. Their jaws can stretch wide to swallow large prey whole.

Female boas incubate eggs inside their bodies and give birth up to 60 live babies. Boas are about 2 feet (0.6 meters) long when they are born and grow continually throughout their 25 to 30-year lifespan. The largest boa constrictor ever found measured 18 feet (5.5 meters).

Hunted for their fine, ornate skin and for sale in the exotic pet trade, some boa constrictors are endangered and most have protected status in their range.

Reptile Features

  • Photo: Close view of a Nile crocodile's eye

    King Crocs

    The reptiles were once on top of the world. Why did they fall? Find out in this National Geographic magazine feature.

  • Photo: A king cobra with head raised

    King Cobra

    Come eye-to-eye with the king cobra, the longest venomous snake in the world. Learn why it is the reptile of choice for exotic snake charmers.

  • Boy Croc Meets Girl Croc

    With snout-rubbing and bubble-blowing, two amorous saltwater crocodiles get cuddly.

  • Photo: Meller's chameleon on a branch

    Meller's Chameleon

    Learn why this reptile, nicknamed the "giant one-horned chameleon," changes colors. It's not what you think.

  • Black Mamba vs. Animal Kingdom

    It's not a drink or a dance. It's only the black mamba, Africa's longest and the world's fastest snake. Oh, and one of the most poisonous too.

Adobe Flash Player This requires the latest version of Flash Player. Click here to download.

Shop Animals and Nature

Blogs

  • 025577.jpg

    NatGeo NewsWatch

    Keep current on developments in science, nature, and cultures.

  • Photo: Cesar Milan

    Dog Whisperer

    Get the inside story as Cesar Millan helps problem dogs and their owners.

  • Photo: Adventure by boat

    BlogWild

    National Geographic explorers share tales (and photos) of their adventures.