Rubber Boa
Charina bottae • Order: Squamata, Suborder: Serpentes, Family: Boidae, Subfamily: Charininae, Genus: Charina, Species: Charina bottae
Venomous Status
Non-venomous
Danger Level
Harmless - They are widely considered the most docile snake in the world and almost never bite humans, even when handled.
Geographic Range
Western United States and Canada, ranging from British Columbia south to Central California, and east to Utah, Wyoming, and Montana.
Conservation Status
IUCN Red List: Least Concern. Generally stable, though local populations can be affected by habitat loss and fragmentation.
Physical Description
Smooth, small scales giving a rubbery appearance and texture. Color is typically a uniform tan, olive, or chocolate brown. The head is blunt and barely distinct from the neck, with small eyes and vertical pupils. The tail is short and blunt, resembling the head.
Size & Dimensions
The specimen in the photo appears to be a small adult or sub-adult, roughly 12-15 inches. Typical adult size ranges from 14 to 33 inches (35-84 cm).
Habitat
Montane forests, grasslands, and woodland edges from sea level to over 10,000 feet. Often found in microhabitats such as rotting logs, rock crevices, or under forest litter.
Behavior & Temperament
Nocturnal and crepuscular; highly fossorial (burrowing). Extremely docile temperament. When threatened, they often ball up and present their blunt tail as a 'decoy head' while keeping their actual head protected.
Diet & Feeding
Primarily preys on nestling mice and shrews, as well as lizard eggs and small snakes. They use constriction to kill prey and are known to raid rodent burrows.
Reproduction
Viviparous (gives birth to live young); typical litter size is 2 to 8 neonates. Breeding occurs in spring with births in late summer or fall.
Venom Profile
Venom Type
Non-venomous - no medically significant venom.
AI-generated — see a qualified source if acting on this. For any snakebite, call emergency services immediately.
Look-alikes
Rosy Boas (Lichanura trivirgata) usually have stripes; Smooth Greensnakes (Opheodrys vernalis) are bright green. The blunt tail is a key diagnostic feature separating it from most colubrids.
Conservation Status
IUCN Red List: Least Concern. Generally stable, though local populations can be affected by habitat loss and fragmentation.
Cultural Significance
Referred to as 'the two-headed snake' by some Indigenous groups due to their blunt tails. They play an important ecological role in controlling rodent populations.
Notable Features
One of only two species of boa native to the United States. They are extremely cold-tolerant for snakes and possess vestigial pelvic spurs (remnants of hind limbs) near the vent.
Notes
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