The Rosy Boa (Lichanura trivirgata) and several of the Sand Boas (Eryx spp.) are among the most unique of the 53 species in the family Boidae. They are excellent choices for both beginning and advanced keepers, especially those with limited space. Stoutly-built but averaging only 24-30 inches in length, these “big snakes in a small package” are hardy, relatively easy to handle and breed, and adapt well to small enclosures.
Rosy and Sand Boas have made similar adaptations to their environments, but live on opposite sides of the globe – a phenomenon known as convergent evolution. Both are highly-specialized burrowers, spending most of their time below-ground in warm, dry habitats. Along with the equally-unusual Rubber Boa (Charina bottae) and African Burrowing “Python” (Calabaria reinhardtii), they are classified in the subfamily Erycinae.
Many people associate boas with humid forests, but the Rosy Boa inhabits deserts and arid scrubland from Southern California through southwestern Arizona to Baja California and Sonora, Mexico. Three subspecies are known.
Many are blue-gray and attractively marked with 3 stripes of pinkish-orange or reddish brown, but natural variations are seemingly endless. Several individuals that I encountered while studying insects in Baja California, Mexico stand out as being among the most beautiful snakes I’ve seen. A number of unique color strains, ranging from black through orange-striped to white, have been developed by hobbyists.
The Sand Boas
Twelve species of Sand Boa make their homes in deserts and arid scrub habitats in Africa, South Asia and the Middle East. The Egyptian and Kenyan Sand Boas (Eryx colubrinus loveridgei and E. c. colubrinus), are the most commonly-kept species. Both average less than 2 feet in length and are attractively patterned, with the Kenyan being particularly bright in color. The Indian Sand Boa (Eryx johnii), which may exceed 3 feet in length, is not commonly seen in US collections.
Sand Boas are highly-specialized ambush predators that wait below the substrate for passing rodents and lizards. To assist is this hunting strategy, the eyes and nostrils are placed high on the head. Captives will explode from their hiding places to snatch small mice moved about with a feeding tong…very impressive!
Both species are generally inoffensive, although their smooth, glossy scales may render handling a bit tricky.
Rosy Boas are often content to be held, and tend to hide their heads when frightened. Sand Boas, however, usually become stressed when removed from their subterranean hideaways.
Sand Boas have an ingrained feeding response that often causes them to strike if touched while buried, so care should be taken when working in their terrariums (touching the body with a small mouse held via tongs may tempt a reluctant feeder).
Setting up the Terrarium
The 8-12 inch-long youngsters may be housed in a 10 gallon aquarium. Adults and pairs can be accommodated in 20-30 gallon tanks. The screen top must be secured with clips or locks.
Rosy and Sand Boas are naturally secretive; being forced to remain in the open is a stressful experience, even for long-term pets.
Sand Boas must be given a deep substrate of smooth-grained sand in which to burrow. As security is provided by the feeling of contact with the substrate, cave-type retreats will not suffice. Some individuals will burrow beneath a piece of glass laid atop the sand, and so may be easily observed.
Boas do not require exposure to UVB light. A day: night cycle of 12:12 hours can be used year-round, but shortening the day-length and lowering the temperature during winter will stimulate breeding. Please see the articles below for further information on breeding.
The ambient temperature of 78-85 F is ideal. An incandescent bulb should be used to create a basking spot of 90-95 F. Heat pads placed below the aquarium work well for Sand Boas, which rarely if ever emerge to bask. Heat pads do not effectively warm the air, and so should be used in conjunction with a bulb.
Large enclosures will enable you to establish a thermal gradient (areas of different temperatures). Thermal gradients, critical to good health, allow snakes to regulate their body temperatures by moving from hot to cooler areas.
Rosy and Sand Boas must be kept dry, as skin and respiratory disorders develop rapidly in damp conditions.
Water bowls should be filled to a point where they will not overflow if the snake curls up within, and must be tip-proof. Rosy and Sand Boas under my care did fine when given access to water bowls for a few hours, 2-3 times weekly.
Rosy and Sand Boas readily accept pre-killed fuzzies or small mice; hatchlings can usually handle pinkies. Sand Boas will explode from beneath the substrate in response to a meal wiggled about via feeding tongs.
Both species have rather small heads (wedge-shaped in the Sand Boa, to assist in burrowing) and their jaws are not well-suited to swallowing large meals. Fuzzies and young mice are preferable to adult mice.
Hatchlings should be fed once weekly, adults each 10-14 days. Vitamin and mineral supplements are not necessary.
Mexican Dwarf Pythons (Loxocemus bicolor) and Calabar Ground or African Burrowing Pythons (Calabaria reinhardtii) share many traits with Rosy and Sand Boas. Please see this article for further information on keeping these unusual fossorial snakes.
Rosy Boa in substrate image referenced from wikipedia and originally posted by LtShears
Indian Sand Boa in substrate image referenced from wikipedia and originally posted by KLPrice
Sand Boa in substrate image referenced from wikipedia and originally posted by OpenCage