Scientific Name: Constrictor constrictor
Range/Habitat: Tropical Central and South America; Forests, stream banks, croplands
Diet: A variety of prey including lizards, birds, rodents, monkeys and even wild pigs
Description: Common boas are thick-bodied snakes that can be 3-14 feet (0.9-4.3 m) long and can weigh more than 100 pounds (45 kg). Most mature at 5-8 feet (1.5-2.4 m) long and weigh less than 60 pounds (27 kg). They have oval, diamond, or bat-shaped patterns of reddish-brown outlined in black, on a background of cream, pale tan or gray. “Red-tailed boas” aren’t another species, but a color variation.
Their relatively short tails are prehensile and able to securely grip branches. They have many small teeth for gripping their prey, but no fangs or venom. Boas have spurs near the cloacae that are vestiges of the legs possessed by ancestors. In females, the spurs are usually smaller or less hooked, and may be absent.
Family Life: Common boas are ovo-viviparous, which means the female retains her eggs internally until they hatch, so she bears live young. Most clutches number 20-50 thin-membraned eggs. The neonates are born after 100-150 days of development. Females can store sperm for quite some time before fertilization takes place, so the total apparent gestation can take 10 months. The female will usually eat little or nothing while she is retaining eggs (called gravid in reptiles).
Nature Notes: Boas breathe with both lungs; most other snakes have only one functional lung. They can live 20 years or more in captivity.
Status in the Wild: Threatened