Boa Constrictor

Boa Constrictor

Scientific Classification

Common Name
Genus Species
Boa (type of snake) constrictor (to grasp)

Fast Facts

The boa constrictor is a large, heavy-bodied snake. Their body markings consist of beige blotches on a dark brown background.
Adults range in size from 2.4-3 m (8-10 ft.); some boas can exceed 3.6 m (12 ft.), but lengths of over 11 feet are extremely rare; newborn boas measure about 60 cm (24 in.)
Adult boas weigh approximately 27 kg (60 lb.)
Variety of birds and mammals
8-12 weeks; Females are ovoviviparous - the young develop in eggs that the female retains inside her body. The young hatch from the eggs, then the mother gives birth to the live young.
Sexual Maturity
2-3 years
Life Span
Along with ball pythons, boas are believed to be some of the longest-lived of all snakes. In general, boa constrictors can live 35 or more years. The longest-lived boa ever recorded was 40 years, 4 months.
Boa constrictors are native to Central and South America.
They inhabit dry tropical forests and open areas.
Global: No data
IUCN: Not listed
CITES: Appendix II; one subspecies listed as Appendix I
USFWS: In the United States, 1 subspecies listed as threatened and 2 subspecies as endangered. In addition, several other species are listed.

Fun Facts

  1. Boas are considered primitive snakes, differing from other species by having two vestigial (remnant) hind limbs. These vestigial limbs appear as spurs on either side of the cloaca.
  2. Like all snakes, boas are excellent swimmers, but they usually avoid going into the water as much as possible.
  3. Boas have special heat-sensing pits on their faces that allow them to detect the body heat of their prey. Boas are nocturnal hunters - they rely on heat-sensing abilities to hunt in the dark.

Ecology and Conservation

Boas, like many other large snakes, are killed for their skins, which are highly prized in the leather trade. These snakes are not farmed for their skins, and collecting them from the wild has caused population declines.

Boas are also consumed by indigenous people and collected for the pet trade. They have long been popular as pets because of their large size and relatively calm demeanor.

Probably their biggest threats are the ever-increasing human populations and the loss of prime habitat. Boas are very important in controlling rodent populations which, when in excess, can have a seriously negative impact on the environment.


Bauchot, Roland (ed.). Snakes a Natural History. New York: Sterling Publishing Co., Inc., 1994.

Ernst, Carl H., and Zug, George R. Snakes in Question. Washington: Smithsonian Institution Press, 1996.

Mattison, Chris. Snakes of the World. New York: Facts on File Publications, Inc., 1986.

Mehrtens, John M. Living Snakes of the World. New York: Sterling Publishing Co., Inc., 1987.

Stafford, Peter J. Pythons and Boas. New Jersey: T.F.H. Publications, Inc., 1986.