Boidae

The Boidae, commonly known as boas or boids, are a family of nonvenomous snakes. They live in many parts of the world, including the Americas, Africa, Europe, Asia, and some Pacific islands. These snakes are famous for their size; some are among the largest snakes on Earth. The green anaconda from South America is one of the heaviest and second-longest snakes known.

Most boa snakes are medium to large in size. Usually, the females are bigger than the males. Scientists have identified six subfamilies and many different genera and species within this group. Boas are interesting because they are strong and powerful, but they do not use venom to catch their food. Instead, they wrap their bodies around their prey to hold it tightly.

Description

Boas are a type of snake, similar to pythons. They have long bones on the sides of their heads and flexible jaw joints that allow them to open their mouths wide. Both boas and pythons share some basic traits, like a stiff lower jaw and small hind limb spurs that are more noticeable in males. Most boas have teeth on the roof of their mouths and a functional left lung.

Unlike pythons, boas do not have certain bones in their skulls and they give birth to live babies. When they have special sensing pits on their faces, these pits sit between their scales. Boas are found in many parts of the world, including the Americas, Africa, Europe, Asia, and some Pacific islands. They live in different areas than pythons, often preferring unique habitats.

Distribution and habitat

Most boas live in North, Central, and South America, and also in the Caribbean. A few live in southeastern Europe and Asia Minor, North, Central and East Africa, Madagascar, the Arabian Peninsula, Central and Southwestern Asia, India and Sri Lanka, Indonesian islands (Moluccas, West Papua, Talaud, Sulawesi) and Papua New Guinea through Melanesia and Samoa.

Feeding

Boas catch their food by wrapping themselves around it tightly. They wrap their body around the animal quickly and hold it tight. This squeezing stops the animal from breathing, and it eventually stops moving because it can't get air.

Big boas can eat animals about the size of a house cat, and sometimes even bigger! They swallow their food whole, which can take many days or weeks to digest. Even though they look scary, boas are not dangerous to people. They don't crush their food to death; instead, the food stops breathing while being held tightly.

Reproduction

Most boas are born live, meaning the mother gives birth to live babies instead of laying eggs. This is different from pythons, which lay eggs to have their babies.

Subfamilies

Type genus = Boa – Gray, 1825

Taxonomy

Pythons used to be considered part of the boa family, called Pythoninae, but scientists later found they are not closely related to boas even though they look similar.

Most non-boa boids are now placed in their own separate families, including Calabariidae, Candoiidae, Charinidae, Erycidae, Sanziniidae, and Ungaliophiidae. The way scientists classify boid snakes has been debated for a long time. Deciding which group a boid snake belongs to—like a family or subfamily—is sometimes a matter of choice.

The Ungaliophiinae subfamily used to include four groups of snakes. Two of these (Tropidophis and Trachyboa) are more closely related to the American pipe snake (Anilius scytale) and are now in the family Tropidophiidae. The other two groups (Ungaliophis and Exiliboa) are closely related to the Charina/Lichanura group within the boa family.