Rubber Boa
Charina botae • Order: Squamata, Suborder: Serpentes, Family: Boidae, Subfamily: Charininae, Genus: Charina, Species: Charina botae
Venomous Status
Non-venomous
Danger Level
Harmless; they are one of the most docile snakes in the world and almost never bite humans, even in self-defense.
Geographic Range
Western United States and southwestern Canada. Occurring from British Columbia south through Washington, Oregon, and California into Idaho, Montana, Wyoming, Utah, and Nevada.
Conservation Status
IUCN Red List: Least Concern. Generally stable, though local populations can be affected by habitat destruction and fragmentation.
Physical Description
Small, uniform brown-to-olive-green coloration with a smooth, shiny, and rubbery texture. The head is not distinct from the neck, and the tail is short and blunt, resembling the head. Scales are small and smooth. Eyes are small with vertical pupils.
Size & Dimensions
The specimen in the image appears to be an adult, approximately 15-20 inches long. The species typically ranges from 14 to 33 inches (35–84 cm) in total length.
Habitat
Extremely varied, ranging from sea level to over 3,000 meters. Found in coniferous forests, grasslands, and chaparral. They prefer moist conditions and are often found in microhabitats like rotting logs, leaf litter, and rock crevices.
Behavior & Temperament
Primarily nocturnal and crepuscular, but active during the day in cool weather. They are slow-moving and fossorial (burrowing). When threatened, they roll into a ball and use their blunt tail as a decoy 'head' to provoke attacks away from their actual head.
Diet & Feeding
Specializes in preying on nestling mice and shrews, as well as lizard eggs and small lizards. They are constrictors. Often, the boa will fight off adult rodents with its tail while consuming the nestlings.
Reproduction
Viviparous (gives birth to live young). Litters typically consist of 2 to 8 young, born in late summer or autumn.
Venom & Safety
Venom Type
Non-venomous - no medically significant venom.
First Aid Advice
No medical intervention is required for a bite from this species beyond standard wound cleaning (soap and water). Antivenom is not applicable.
Look-alikes
Rosy Boas (Lichanura trivirgata) which have stripes; Southern Rubber Boas (Charina umbratica) which are physically similar but restricted to specific CA mountain ranges; and various Garter Snakes (Thamnophis) which have stripes and keeled scales.
Conservation Status
IUCN Red List: Least Concern. Generally stable, though local populations can be affected by habitat destruction and fragmentation.
Cultural Significance
Known as the 'two-headed snake' by some indigenous groups due to its blunt tail. They play a vital ecological role in controlling small mammal populations.
Notable Features
Often referred to as the 'cold-weather boa' because they are exceptionally cold-tolerant for a reptile. Their blunt tail is frequently covered in scars from defending against mother rodents while the snake eats their young.