Coastal Rosy Boa

Lichanura trivirgata roseofusca


Non-Venomous - considered harmless to humans.

Adults 17–44 in (43–112 in) but generally under 36 inches. The largest Rosy Boa subspecies. Hatchlings are 10-14 inches long.[1]. A moderately heavy-bodied snake with smooth scales and a short, tapered, and slightly prehensile tail that has a blunt tip. Dorsal scales are small and ventral scales are narrow. The head has an elongated shape and is slightly broader then the neck. The eyes have a vertically elliptical pupil. Male rosy boas are typically smaller than females and have more prominent anal spurs.[2]

Three stripes run along the length of the body. Coloration varies and can range from a light grey, bluish-grey to golden brown background color with dark to light rusty stripes. The stripes can be either well defined or not depending on the locality. Some almost appear unicolored.

Similar Species


Most commonly encountered in rocky habitats that are generally in dry shrublands, desert, and near desert environments. Rocks, crevices, and rodent burrows are used for shelter. Preferred habitat is often on south-facing hillsides at elevations from sea level to over 2,000 meters. Favored areas seem to be in close proximity to free water, but they are not confined to such areas.[2] Can be encountered on roads that run through its habitat, often times crawling along the shoulder.


As with many other snakes, the lives a fairly secretive life. During the hot, summer months, they tend to be primarily nocturnal, but activity patterns depend on weather. They can be crepuscular at times, and in late winter and early spring can be diurnal.[2] Movement is relatively slow and rarely over long distances.[3]


Viviparous. Courtship and mating occur from May through July and gestation requires 103 to 143 days. Females give birth to live, independent young between August and November. Litters average 3 to 8 young, with a range of 1 to 14. Males apparently reach sexual maturity at 2 to 3 years of age, at a total length of 43 to 58 cm; females also mature in 2 or 3 years, at a length of about 60 cm.[2]


A constrictor. Will slowly stalk or ambush its prey which include rodents, small birds, lizards, small snakes, and amphibians.[1]


Occurs in southwestern California to the coastal slopes of the San Gabriel and San Bernardino mountains, and across the peninsular ranges into the desert in San Diego County. Snakes in the eastern San Gorgonio pass and Palm Springs area are considered integrades with the Desert Rosy Boa - Lichanura trivirgata gracia.[1]

Meaning of Scientific Name

The genus name, Lichanura comes from the Greek “lichanos,” meaning forefinger, and “oura,” meaning tail. This is possibly referring to the stumpy appearance of its tail or from its body form.[4]

The species name trivirgata comes from the Latin “tri,” meaning three, and “virgata,” meaning striped. This is referring to the color pattern.[4]

The subspecies name roseofusca comes from the Latin “roseus,” meaning ruddy, and “fusca,” meaning dusky. This is referring to the characteristic coloration of this subspecies.[4]

Conservation Status

The Bureau of Land Management in the State of California has listed it as a “sensitive” species.[5]

Taxonomic Notes

L.t. roseofusca are most closely related to Charina, or the rubber boa. Kluge (1993) placed rosy boas into the genus Charina, however, this arrangement has been questioned, and most recent checklists retain rosy boas in the genus Lichanura.[2] The main difference between L. trivirgata and Charina is that Charina have enlarged scales on their head and do not exhibit striping, making them appear more unicolored.


  1. Nafis, Gary, California,
  2. Dacres, K, and J Harding, Animal Diversity Web,
  3. Diffendorfer, James E., Carlton Rochester, Robert N. Fisher, and Tracey K. Brown, Journal of Herpetology,
  4. Beltz, Ellin. Scientific and Common Names of the Reptiles and Amphibians of North America - Explained,, 2006
  5. California Department of Fish and Game,

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