The Rubber Boa is a snake in the family Boidae that is native to the Western United States.
The Rubber Boa (Charina bottae) is a snake in the family Boidae and genus Charina. The name Charina is from the Greek for graceful or delightful, and the name bottae honors Dr. Paolo E. Botta, an Italian ship's surgeon, explorer and naturalist. The Boidae family consists of the nonvenomous snakes commonly called boas and consists of 43 species. The genus Charina consists of four species, three of which are found in North America, and one species found in Africa. It is sometimes also known as the Coastal Rubber Boa or the Northern Rubber Boa and is not to be confused with the Southern Rubber Boa (Charina umbratica). There is debate on whether the Southern Rubber Boa should be a separate species or a subspecies (Charina bottae umbratica). The only other boa species found in the United States is the Rosy Boa (Lichanura trivirgata).
Rubber Boas are one of the smaller boa species, adults can be anywhere from 15 to 33 inches (840 mm) long; and newborns are typically 7.5 to 9 inches (230 mm) long. The common name is derived from their skin which is often loose and wrinkled and consists of small scales that are smooth and shiny, these characteristics give the snakes a rubber like look and texture. Colors are typically tan to dark brown with a lighter ventral surface but sometimes olive-green, yellow, or orange. Newborns often appear pink and slightly transparent but darken with age. Rubber boas have small eyes with vertically elliptical pupils and short blunt heads that are no wider than the body. One of the most identifiable characteristics of Rubber Boas is their short blunt tails that closely resemble the shape of their head. Rubber Boas appear quite different visually than any other species that share the same range (except maybe for the Southern Rubber Boa) and thus are usually easy to identify.
Characteristics of Rubber Boas behavior also set them apart from other snakes. Rubber Boas are considered one of the most docile of the boa species and are often used to help people overcome their fear of snakes. Rubber Boas are known to never strike at or bite a human under any circumstances but will release a potent musk from their vent if they feel threatened. They are primarily nocturnal and likely crepuscular (active during dawn and dusk) which partially contributes to how rarely they are encountered. Because of the temperate regions they inhabit Rubber Boas hibernate during the winter months in underground dens Hunting – Rubber Boas primarily feed on young mammals such as shrews, voles, mice, etc. When nestling mammals are encountered they will try to consume the entire litter if possible and fend off the mother with their tail, this is why individuals will often have extensive scarring on their tails. Rubber Boas have also been known to prey on snake eggs, lizard eggs, lizards, young birds, young bats, and there have even been instances of them eating other snakes. Predation – Rubber Boas can be preyed upon by almost any reasonably sized predator in their habitat. When threatened, Rubber Boas will curl into a ball, bury their head inside, and expose their tail to mimic their head. While this is thought to be a primary defense technique against predators, it is doubtful that this behavior is effective in most cases being that many predators are too large (raptors, coyotes, raccoons, cats, etc.). In reality the best defense of Rubber Boas is their secretive nature.