The elevation range of this species can be from sea level to 3,050 m (about 10,000 ft), but they prefer elevations of 1540-2,460 meters (about 5,000-8,000 ft).
Rubber boas (C. b. bottae) and southern (C. b. umbratica) rubber boas. Southern rubber boas tend to be slightly smaller in size. Northern and southern populations also have a few notable distinctions in scale shape and number. Northern rubber boas tend to have “subtriangle” frontal scales (head scales) that have a convex posterior margin with 42 or more middorsal scale rows and 197 or more ventral scales, whereas southern rubber boas have “subrectangular” frontal scales with straight or barely convex posterior margin, 41 or fewer middorsal scale rows, and 196 or fewer ventral scales. All rubber boas are typically brown to olive green in color on top and yellow to cream on the bottom. They have small, dark eyes with vertical pupils. Rubber boas look and feel like rubber, giving them their name. They have small, smooth scales and wrinkled skin that create this effect. While this snake is usually one solid color without breaks or patterns, sometimes dark spots or mottling can occur on top. This is more common in northern populations. Similarly, dark mottling can occur on the belly but is not common.) can grow to be between 35 and 84 cm, however, they usually fall between 38 and 64 cm. Newly hatched individuals are 19 to 23 cm. There are two subspecies: northern (
The most notable defining feature of rubber boas are their tail. They have a specialized tail that has a thick bulb of bone and looks a lot like their head. When threatened, they curl up and stick their tail out to imitate their head, causing the predator to attack this extremely durable tail instead of their head. Because of this, their tails are usually scarred. This tail is also prehensile, which means it can grasp things. This allows rubber boas to climb shrubs and other small vegetation, as well as swim remarkably well. (Chappell and Ellis, 1987; Hoyer and Stewart, 2000a; "Southern Rubber Boa", 2013; "Northern Rubber Boa", 2023a; "Northern Rubber Boa - Charina bottae", 2023; "Rubber Boa Care Sheet", 2022; Rodrı́guez-Robles, et al., 2001)
Newborns are much like their adult counterparts, only smaller and brighter in color. No metamorphosis is involved in the transition from juvenile to adult for rubber boas. Rubber boas also don’t experience indeterminate growth. Sex is determined by their size in general and the size of their spurs. Females tend to be larger with smaller spurs than males. ("Rubber Boa Care Sheet", 2022)
Rubber boas seek out mates immediately after they come out of hibernation in spring. It can be inferred that both males and females seek each other out, but this was not explicitly stated. Rubber boas only breed during this time each year. Females can have up to 9 young per year, but it’s more typical for them to give birth only once every three to four years. It has not been stated whether rubber boas mate with the same snakes or different ones every few years. Rubber boas are solitary snakes, aside from breeding season. Their territories can overlap, but they aren’t territorial and don’t interact. No further mating information was available. ("Rubber Boa", 2023; "Rubber Boa Care Sheet", 2022)
Rubber boas mate in the spring right after they come out of hibernation. The gestation period is about 5 months and the offspring are born in the months August to November. Rubber boas are viviparous (birth live offspring) and they can have up to 9 hatchlings per year, but females tend to only reproduce once every three to four years. Females fast for the duration of their pregnancy and lay in the sun. The clutch of young is about 19-23 cm in length and born fully developed. Female rubber boas reach maturity at around 4-5 years old, while males reach maturity sooner at around 3-4 years old. Young are usually on their own before this, however, as they leave the spring after their first hibernation. ("Rubber Boa", 2023; "Northern Rubber Boa", 2023b)
Female rubber boas give live birth to a clutch size of around 2-5 young once every three to four years. There are usually more females born than males, however, males tend to outnumber females as adults, suggesting that females have a greater mortality rate than males. The greater number of females in the litter size might be a mechanism to counteract this mortality rate. The gestation period is usually about 5 months and occurs in April right after the rubber boas come out of hibernation. The females tend to be larger and this helps them give birth to large, live young. It also allows them to store extra fat that they use during their gestation period since they fast for the duration of it. Young are born from August to November and captive snakes birth young about 2 weeks earlier. Females invest about half of their own body weight into birthing their young. After birth, the young are protected and given shelter until the spring after their first hibernation when they set off on their own. The young reach maturity later after they leave their parent’s protection. For males, this is around 2-3 years of age, and for females, it is around 3-4 years of age. ("Northern Rubber Boa", 2023b; Hoyer and Stewart, 2000b)
Rubber boas ( ("Rubber Boa", 2023)) have a small home range and tend to stay in the same place every year unless forced to move by external pressures like predators or losing habitat.
Rubber boas (Peromyscus leucopus), voles (Microtus), and shrews (Soricidae). They also eat lizard eggs and other snake’s eggs occasionally. Very rarely, rubber boas prey on lizards, small birds and bats, and other snakes. They hunt during the night, but not much other information on hunting habitats is available. ("Rubber Boa", 2023; "Northern Rubber Boa", 2023b; Hoyer and Stewart, 2000b)) is a carnivore and likes to feed on nesting mammals like white-footed mice (
The juveniles of Buteo), owls (Strigiformes), raptors (Falconiformes), skunks (Mephitidae), raccoons (Procyon lotor), coyotes (Canis latrans), and cats (Felis catus). ("Rubber Boa", 2023; "Southern Rubber Boa", 2013; "Rubber Boa Care Sheet", 2022)are protected by their parent until they go out on their own. Rubber boas use their tail as a dummy head to trick predators into attacking the thick bone instead of their head. Rubber boas can also bite and release a musk to deter predators if necessary. They also have coloration that helps them camouflage. When in defense mode, rubber boas have brown on top and cream on their underside. Since they are a secretive and solitary nocturnal species that spend most of their time underground, they are not preyed upon often. When they are, it is by large predators like hawks (
Rubber boas are a solitary species and doesn’t interact with other species or their own outside of predation and mating. They are prey for large hunters that tend to be nocturnal since they spend most of their time underground aside to hunt, which they do at night. These large predators include hawks, owls, raccoons, coyotes, and others. Rubber boas hunt small, nesting animals like mice and shrews. Occasionally, they will eat lizard or snake eggs. ("Rubber Boa", 2023; "Southern Rubber Boa", 2013; "Rubber Boa Care Sheet", 2022)
Rubber boas are a popular pet and is even over-collected from their natural habitats because of their docile nature. They feed on small nesting animals that might make their homes in human food storage areas. Besides that, rubber boas don't affect the ecosystem in any special way that benefits humans. ("Northern Rubber Boa", 2023a; "Rubber Boa Care Sheet", 2022)
There are no known adverse effects of ("Northern Rubber Boa - Charina bottae", 2023)on humans.
According to IUCN Red List, the Southern Rubber Boa is vulnerable, but the Northern Rubber Boa is of least concern. The US Federal List did not have the Southern Rubber Boa listed as any status and didn't have the Northern Rubber Boa listed at all. CITES had no information on either of the subspecies. The State of Michigan List had no information on either subspecies. The Southern Rubber Boa is considered a threatened species in the state of California due to habitat loss from human development, water diversion, and soil disturbances. The Northern Rubber Boa is listed as a "Priority Species" and "Unprotected" in the state of Nevada due to drought and overcollection. Population estimates are unknown. ("Rubber Boa", 2023; "Southern Rubber Boa", 2013; "Northern Rubber Boa", 2023a)
The “bottae” in the scientific name of the rubber boa is to honor Paolo Emilio Botta who collected the rubber boa in the 19th century. Botta was an explorer, archaeologist, and diplomat. The “umbratica” in the scientific name comes from Latin meaning shade or seclusion which fits the rubber boa’s reclusive behavior. The "Charina" comes from the Greek language meaning "graceful". ("Northern Rubber Boa - Charina bottae", 2023; Stewart, 1977)
Jade Collins (author), Colorado State University, Tanya Dewey (editor), University of Michigan-Ann Arbor.
living in the Nearctic biogeographic province, the northern part of the New World. This includes Greenland, the Canadian Arctic islands, and all of the North American as far south as the highlands of central Mexico.
uses sound to communicate
having body symmetry such that the animal can be divided in one plane into two mirror-image halves. Animals with bilateral symmetry have dorsal and ventral sides, as well as anterior and posterior ends. Synapomorphy of the Bilateria.
an animal that mainly eats meat
uses smells or other chemicals to communicate
active at dawn and dusk
having markings, coloration, shapes, or other features that cause an animal to be camouflaged in its natural environment; being difficult to see or otherwise detect.
animals which must use heat acquired from the environment and behavioral adaptations to regulate body temperature
union of egg and spermatozoan
forest biomes are dominated by trees, otherwise forest biomes can vary widely in amount of precipitation and seasonality.
the state that some animals enter during winter in which normal physiological processes are significantly reduced, thus lowering the animal's energy requirements. The act or condition of passing winter in a torpid or resting state, typically involving the abandonment of homoiothermy in mammals.
Having one mate at a time.
having the capacity to move from one place to another.
This terrestrial biome includes summits of high mountains, either without vegetation or covered by low, tundra-like vegetation.
the area in which the animal is naturally found, the region in which it is endemic.
active during the night
reproduction in which eggs develop within the maternal body without additional nourishment from the parent and hatch within the parent or immediately after laying.
the business of buying and selling animals for people to keep in their homes as pets.
Referring to something living or located adjacent to a waterbody (usually, but not always, a river or stream).
breeding is confined to a particular season
remains in the same area
reproduction that includes combining the genetic contribution of two individuals, a male and a female
digs and breaks up soil so air and water can get in
uses touch to communicate
that region of the Earth between 23.5 degrees North and 60 degrees North (between the Tropic of Cancer and the Arctic Circle) and between 23.5 degrees South and 60 degrees South (between the Tropic of Capricorn and the Antarctic Circle).
Living on the ground.
A terrestrial biome. Savannas are grasslands with scattered individual trees that do not form a closed canopy. Extensive savannas are found in parts of subtropical and tropical Africa and South America, and in Australia.
A grassland with scattered trees or scattered clumps of trees, a type of community intermediate between grassland and forest. See also Tropical savanna and grassland biome.
A terrestrial biome found in temperate latitudes (>23.5° N or S latitude). Vegetation is made up mostly of grasses, the height and species diversity of which depend largely on the amount of moisture available. Fire and grazing are important in the long-term maintenance of grasslands.
uses sight to communicate
reproduction in which fertilization and development take place within the female body and the developing embryo derives nourishment from the female.
young are relatively well-developed when born
2023. "Northern Rubber Boa - Charina bottae" (On-line). California Herps. Accessed February 12, 2023 at https://californiaherps.com/snakes/pages/c.bottae.html.
Burke Museum. 2023. "Northern Rubber Boa" (On-line). Burke Museum. Accessed March 02, 2023 at https://www.burkemuseum.org/collections-and-research/biology/herpetology/amphibians-reptiles-washington/northern-rubber-boa.
Nevada Department of Wildlife. 2023. "Northern Rubber Boa" (On-line). Nevada Department of Wildlife. Accessed February 05, 2023 at https://www.ndow.org/species/northern-rubber-boa/#.
Reptiles Cove. 2022. "Rubber Boa Care Sheet" (On-line). Reptiles Cove. Accessed February 26, 2023 at https://reptilescove.com/care/snakes/rubber-boa.
Animalia. 2023. "Rubber Boa" (On-line). Animalia. Accessed February 16, 2023 at https://animalia.bio/rubber-boa?taxonomy=986.
Los Padres ForestWatch, Inc. 2013. "Southern Rubber Boa" (On-line). Accessed February 05, 2023 at https://lpfw.org/wp-content/uploads/pdf/SouthernRubberBoa.pdf.
Chappell, M., T. Ellis. 1987. Resting metabolic rates in boid snakes: allometric relationships and temperature effects. Journal of Comparative Physiology B, 157: 227–235. Accessed February 26, 2023 at https://doi.org/10.1007/BF00692367.
Dorcas, M., C. Peterson. 1998. Daily Body Temperature Variation in Free-Ranging Rubber Boas. Herpetologica, 54/1: 88-103. Accessed February 12, 2023 at https://www.jstor.org/stable/3893400.
Dorcas, M., C. Peterson, M. Flint. 1997. The Thermal Biology of Digestion in Rubber Boas (Charina bottae): Physiology, Behavior, and Environmental Constraints. The University of Chicago Press Journals, 70/3. Accessed February 05, 2023 at https://www.journals.uchicago.edu/doi/10.1086/639601#pane-pcw-related.
Field Guides, M. 2023. "Northern Rubber Boa - Charina bottae" (On-line). mt.gov. Accessed March 10, 2023 at https://fieldguide.mt.gov/speciesDetail.aspx?elcode=arada01010.
Hoyer, R., G. Stewart. 2000. Biology of the Rubber Boa (Charina bottae), with Emphasis on C. b. umbratica. Part I: Capture, Size, Sexual Dimorphism, and Reproduction. Journal of Herpetology, 34: 348-354. Accessed February 05, 2023 at https://www.jstor.org/stable/1565355?origin=crossref#metadata_info_tab_contents.
Hoyer, R., G. Stewart. 2000. Biology of the Rubber Boa (Charina bottae), with Emphasis on C. b. umbratica. Part II: Diet, Antagonists, and Predators. Journal of Herpetology, 34: 354-360. Accessed February 05, 2023 at https://www.jstor.org/stable/1565356?origin=crossref&seq=3#metadata_info_tab_contents.
Kidadl, T., M. Kochhar, D. Gupta. 2022. "Fun Rubber Boa Facts For Kids" (On-line). Kidadl. Accessed March 10, 2023 at https://kidadl.com/facts/animals/rubber-boa-facts.
Rodrı́guez-Robles, J., G. Stewart, T. Papenfuss. 2001. Mitochondrial DNA-Based Phylogeography of North American Rubber Boas, Charina bottae (Serpentes: Boidae). Molecular Phylogenetics and Evolution, 18/2: 227-237. Accessed February 05, 2023 at https://www.sciencedirect.com/science/article/pii/S1055790300908868?via%3Dihub.
Stewart, G. 1977. Charina, C. bottae. Catalogue of American Amphibians and Reptiles (CAAR), 1: 205-206. Accessed February 12, 2023 at http://hdl.handle.net/2152/45131.
Zhang, Y., M. Westfall, K. Hermes, M. Dorcas. 2008. Physiological and behavioral control of heating and cooling rates in rubber boas, Charina bottae. Journal of Thermal Biology, 33/1: 7-11. Accessed February 05, 2023 at https://www.sciencedirect.com/science/article/pii/S0306456507000903?via%3Dihub.