What to Know About the Rosy Boa


In this Article

  • What Is a Rosy Boa?
  • Rosy Boa Characteristics
  • Do Rosy Boas Bite?
  • Rosy Boa Care

Rosy boas are a distinctively colored, small species of boa. They’re one of the only types of boas in the United States, and they make excellent pets.

What Is a Rosy Boa?

The rosy boa (genus Lichanura) is a genus of boas with two species: Lichanura orcutti, the coastal rosy boa, and Lichanura trivirgata, the desert rosy boa. These, plus two species of rubber boa, make up the only species of boas native to the continental U.S. 

Boas, or boa constrictors, are a large type of snake that squeeze their prey. They do this by grabbing their prey with their teeth, wrapping their body around the prey, and squeezing. The goal isn’t to crush the prey, but to squeeze tightly enough that the prey cannot expand its lungs, leading it to suffocate. Every time the prey exhales, the snake squeezes a little more.

Once the snake is wrapped around its prey, it unhinges and stretches its jaw so it can swallow its prey whole. They often start head-first, and muscle contractions pull the prey down the boa’s throat and into its stomach. A boa can do this due to a special tube in the bottom of its mouth that can take in air while it swallows.

Rosy Boa Characteristics

The two species of rosy boa are very similar. Rosy boa size usually measures about 17 to 34 inches (43 to 86 centimeters) in length, although some have been found in parts of coastal California that measure 6 feet long. Rosy boas’ weight ranges from 11 to 21 ounces (0.3 to 0.6 kilograms), and males tend to be smaller than females.

The head and tails of rosy boas are blunt, which serves to confuse predators and also makes it easier for the snake to burrow into the ground. Their heads are covered in small scales, and their pupils are vertical and elliptical.

Rosy boas are named for their pinkish bellies, but the rest of their coloration can vary. They often have three stripes going down their bodies. The stripes are often shades of black, brown, maroon, orange, rose, or rust, with shades of gray, tan, or yellow in between.

For a boa, rosy boas are relatively mild-mannered. They prefer to hide from predators, but if that’s not an option, they’ll confuse the predator by pretending its tail is its head. Rosy boas are also active at different times of day during different times of the year. In the summer, when it’s hot, they’re mainly nocturnal. In spring and fall, they’re diurnal, that is, awake during the day and asleep at night. During winters, they brumate, which means they hide in crevices or underground and their body temperature, heart rate, metabolism, and respiratory rate drop in a state that’s similar to hibernation.

Rosy boa habitat. Both species of rosy boas are found in the southwestern U.S., but their range differs slightly. Desert rosy boas are found in California, Arizona, and northwestern Mexico. Coastal rosy boas, meanwhile, are found in California, Arizona, and Nevada. 

Both species of boa live mainly in desert areas as well as brushlands and rocky scrubs, and prefer to be near streams, canyon floors, and spring seeps. They can be found at elevations ranging from sea level to 4,000 feet above sea level.

Rosy boas prefer to spend most of their lives in crevices and hidden under rocks to stay protected from the elements and predators. They’re often found on granite outcroppings, but sometimes on other types of rock. If they’re in an area where rocks aren’t available, they’ll hide in rodent burrows instead.

Diet. Rosy boas are carnivores. They mainly eat small mammals, like deer mice, kangaroo rats, and pack rats, but will also sometimes eat small birds and lizards.

Boas in general, including rosy boas, are ambush predators. They can stick their tongues in the air to catch scent particles and tell when prey is near. Then, they’ll stay still and hidden until the prey is within striking distance, at which point they’ll spring at their prey with open jaws and bite down on their prey to prevent it from escaping. The boa will start to wrap its body around its prey, squeezing until the prey stops struggling, and then swallow it headfirst.

Rosy boa lifespan and life cycle. In the wild, rosy boas often live 15 to 20 years. In captivity, they can live 30 years or more.

Both males and females reach sexual maturity at about two or three years old. The mating season is usually from May through July. After mating, gestation can take 103 to 143 days. Female rosy boas give birth to live young and may birth one to 14 offspring at a time, with an average of three to eight young in each litter. These babies can be 7 to 14 inches long (18 to 36 centimeters) and often look very similar to adults but with more contrasting color patterns. They are independent immediately after birth.

Do Rosy Boas Bite?

While rosy boas can bite, they mostly bite their prey, not humans. Rosy boas are non-confrontational and prefer other defensive tactics before resorting to biting. They aren’t venomous, so while their bite may hurt, it won’t poison you.

Rosy Boa Care

Thanks to their gorgeous colors, gentle personality, and small size, rosy boas are a favorite pet of snake owners. There are some restrictions on rosy boa trade. They’re a protected species under the Federal Special Concern Act and the Convention on the International Trade of Endangered Species (CITES), meaning that snakes must be purchased through breeders, not taken from the wild.

If you’re purchasing a rosy boa as a pet, keep a few things in mind.

Enclosure. A 20-gallon enclosure is usually a good size for a rosy boa. They don’t need things to climb on, but they do like to burrow, so be sure to provide things like half-logs for them to hide under. The substrate should be dry and about 2 to 4 inches deep. Keep the temperature at about 73°F to 83°F (23°C to 28°C), though it can drop slightly at night.

Food and water. Small feeder mice are a great option for rosy boas. Young boas should be fed once or twice a week, while adults only need to be fed every 7 to 10 days. You can also provide a water bowl for your rosy boa, just be sure it can’t tip it over.

Show Sources

Anapsid: “Rosy Boa.”
Animal Diversity Web: “Charina trivirgata.”
Discovery Place: “Ask a Naturalist: Hibernation vs. brumation vs. estivation.”
Hogle Zoo: “Desert Rosy Boa.”
Integrated Taxonomic Information System: “Lichanura.”
Los Angeles Zoo: “Rosy Boa.”
NatureServe Explorer: “Lichanura orcutti.”
San Diego Zoo: “Boa.”
Turtle Bay: “Rosy Boa Snakes.”

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