Boa, Rosy

Southern California and western Arizona in the United States, southward to Baja California and western Sonora in Mexico.

Rocky areas in coastal sage scrub, chaparral, and desert environments.

One of the smallest members of the Boa family, and rarely grows much larger than 3 feet (1 meter) in length. It has a heavy bodied build, a short, blunt tail and small head.

Average of 15 years. Have lived in captivity as long as 20 years.

Wild: Small mammals and birds.
Zoo: Mice


  • Gestation Period: 4 months
  • Boas are ovoviviparous. The eggs are retained in the female’s body and the young are born alive.
  • Five to six live young, as many as 13 have been reported.
  • Females in wild generally breed only every other year, though this may not be the case in captivity.
  • Sexual maturity occurs at 3 – 4 years.


  • Usually nocturnal but are diurnal in early spring.
  • Mainly terrestrial. Will burrow in the ground or hide under rocks.
  • Sometimes, when attacked by a predator, the boa will coil up into a ball, keeping its head in the center. It then releases a foul smelling musk from glands near the base of their tail. Its blunt tail may act to divert a predator from attacking its head, which remains buried in its coils.
  • It kills its prey by constriction.


  • Usually has a pattern of three, poorly defined, lengthwise stripes-one central and two laterals.
  • Coloration includes shades of gray, tan, or reddish brown.
  • Males can be distinguished from females by the presence of spurs.
  • In the wild the young are born just before winter sets in, the late-season babies do not feed at all, going right into hibernation.

Federal Special Concern Species (FSC). Also protected from international trade by CITES, due to pet trade industry.