The Baja California rat snake ''(Bogertophis rosaliae)'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

of nonvenomous

snake Snakes are elongated, Limbless vertebrate, limbless, carnivore, carnivorous reptiles of the suborder Serpentes . Like all other Squamata, squamates, snakes are ectothermic, amniote vertebrates covered in overlapping Scale (zoology), scales. Ma ...

in the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Colubridae Colubridae (, commonly known as colubrids , from la, coluber, 'snake') is a family of snakes. With 249 genera, it is the largest snake family. The earliest species of the family date back to the Oligocene epoch. Colubrid snakes are found on ever ...

. The species is native to

Baja California Baja California (; 'Lower California'), officially the Free and Sovereign State of Baja California ( es, Estado Libre y Soberano de Baja California), is a state in Mexico. It is the northernmost and westernmost of the 32 federal entities of Mex ...

Mexico Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...

; extreme southern

California California is a U.S. state, state in the Western United States, located along the West Coast of the United States, Pacific Coast. With nearly 39.2million residents across a total area of approximately , it is the List of states and territori ...

; and some islands in the

Sea of Cortés The Gulf of California ( es, Golfo de California), also known as the Sea of Cortés (''Mar de Cortés'') or Sea of Cortez, or less commonly as the Vermilion Sea (''Mar Bermejo''), is a marginal sea of the Pacific Ocean that separates the Baja C ...

Description

The Baja California rat snake is a large, slender colubrid snake with a long head, large eyes, and smooth

dorsal scales In snakes, the dorsal scales are the longitudinal series of plates that encircle the body, but do not include the ventral scales. Campbell JA, Lamar WW (2004). ''The Venomous Reptiles of the Western Hemisphere''. Ithaca and London: Comstock Publis ...

. Adults have a total length (including tail) of . Each dorsal scale contains two apical pits (Price 1990a, 1990b). The dorsum is uniform olive or reddish brown without dark markings on a cream-colored background (Ottley and Jacobsen 1983). Yellowish or greenish coloration extends from the lower sides of the body to the venter (Price 1990b). The iris is yellow-green (Ottley and Jacobsen 1983).

Taxonomic remarks

Dowling and

Price A price is the (usually not negative) quantity of payment or compensation given by one party to another in return for goods or services. In some situations, the price of production has a different name. If the product is a "good" in the c ...

(1988) placed this snake in its own genus, ''

Bogertophis ''Bogertophis'' is a genus of New World rat snakes in the family Colubridae. The genus is endemic to the southwestern United States and northern Mexico. There are two accepted species. Etymology The genus ''Bogertophis'' is named in honor of Am ...

'', based on immunological data, but complications with the data set and the mode of analysis indicated that it was best to regard this species as a member of the

rat snake Rat snakes are members – along with kingsnakes, milk snakes, vine snakes and indigo snakes – of the subfamily Colubrinae of the family Colubridae. They are medium to large constrictors and are found throughout much of the Northern Hemisph ...

genus, ''

Elaphe ''Elaphe'' is a genus of snakes in the family Colubridae. ''Elaphe'' is one of the main genera of the rat snakes, which are found in many regions of the northern hemisphere. ''Elaphe'' species are medium to large constrictors by nature. Althoug ...

'', until further data became available (L. Grismer and John Wright, pers. comm.). No attempts have been made to characterize genetic variation across the geographic range of ''B. rosaliae''. An understanding of that variation is needed to determine whether genetically differentiated populations exist within ''B. rosaliae''. The difficulty in obtaining the requisite material for such a study makes it likely that novel techniques, such as extracting DNA from preserved specimens, will be needed to address this problem.

Geographic range

The Baja California rat snake ranges from extreme southern

Imperial County, California Imperial County is a County (United States), county on the southeast border of the U.S. state of California. As of the 2020 United States Census, 2020 census, the population was 179,702, making it the least populous county in Southern Californi ...

, southward into

Cabo San Lucas Cabo San Lucas (, "Saint Luke Cape"), or simply just Cabo, is a resort city at the southern tip of the Baja California Peninsula, in the Mexican state of Baja California Sur. As at the 2020 Census, the population of the city was 202,694 inhabitan ...

(Price 1990a). Over at least the northern half of its range, it is known from widely disjunctive locations (Ottley and Jacobsen 1983, Price 1990b). Its known elevations range from near sea level to ca. . In the United States, ''B. rosaliae'' is known from only one road-killed specimen, CSDSNH 644161 taken 26 May 1984 on Interstate Highway 8, east of Mountain Spring (Imperial County), California. Although Stebbins (1985) and others believe this locality to be genuine (L. Grismer and G. Pregill, pers. comm.), some have questioned the validity of this record (S. Barry, J. Copp, and C. Fagan, pers. comm.).

Life history

The life history of ''B. rosaliae'' is virtually unknown (Price 1990b). The

seems to be nocturnal or crepuscular and may be surface active during daylight hours under suitable conditions (Ottley and Jacobsen 1983). Nothing is known about reproduction or growth except that clutches with an unspecified number of eggs have been laid in captivity (Price 1990b). The few data on diet and behavior are based on captive specimens and are difficult to interpret in the absence of data on this snake under field conditions. If similar to other rat snakes, it climbs easily (Wright and Wright 1957) and adults are probably long-lived (see Bowler 1977). No data on movement, colonization abilities, or the potential predators of this taxon exist.

Habitat

''B. rosaliae'' is largely confined to mesic and dry desert habitats (rocky arroyos and washes) in the immediate vicinity of small springs (Ottley and Jacobsen 1983, Stebbins 1985) but individuals have also been observed on hillsides and dry mesas away from water sources (L. Grismer, pers. comm.). The habitat components critical to this snake have not been identified precisely, but it may require some kind of shrub or tree with a moderately dense crown in which to take refuge because it has been taken in native fan palms (''

Washingtonia ''Washingtonia'' is a genus of palms, native to the southwestern United States (in southern California, and southwest Arizona) and northwest Mexico (in Baja California and Sonora). Both ''Washingtonia'' species are commonly cultivated across t ...

'' spp.),

date palm ''Phoenix dactylifera'', commonly known as date or date palm, is a flowering plant species in the palm family, Arecaceae, cultivated for its edible sweet fruit called dates. The species is widely cultivated across northern Africa, the Middle Eas ...

s (''Phoenix dactylifera''),

mesquite Mesquite is a common name for several plants in the genus ''Prosopis'', which contains over 40 species of small leguminous trees. They are native to dry areas in the Americas. They have extremely long roots to seek water from very far under grou ...

, palo blanco (''

Lysiloma ''Lysiloma'' is a genus of flowering plants in the family Fabaceae. The genus is native to the Americas, and species range from Arizona and New Mexico through Mexico and Central America to Costa Rica, and in Florida, Cuba, Hispaniola, the Bahama ...

candidum''), palo verde, and

creosote bush ''Larrea tridentata'', called creosote bush and greasewood as a plant, chaparral as a medicinal herb, and ''gobernadora'' (Spanish language, Spanish for "governess") in Mexico, due to its ability to secure more water by inhibiting the growth of n ...

associations in the past (Price 1990b). The locations of

oviposition The ovipositor is a tube-like organ used by some animals, especially insects, for the laying of eggs. In insects, an ovipositor consists of a maximum of three pairs of appendages. The details and morphology of the ovipositor vary, but typical ...

sites are unknown.

Status and habitat recommendations

The California State Government classes its status as "Special Concern". It notes that the snake is an infrequently observed

avidly sought after by amateur, scientific, and professional collectors alike. Because of the uncertain status of the single record from California, it believes that it should remain protected until further information regarding its distribution within the state becomes available. The California Department of Fish and Game Habitat Conservation Planning Branch recommends that intensive surveys of habitats with shrubs or trees having a moderately significant crown in Imperial and San Diego counties are needed to determine whether this snake is really part of the herpetofauna of California. If populations are discovered, the Planning Branch states that the local habitat needs to be protected from modification and potential collecting, and some kind of monitoring for this taxon should be initiated.

Footnotes

Sources

* Text in this article has been taken directly from the public domain sourc
Amphibian and Reptile Species of Special Concern in California, Baja California Rat Snake. California Department of Fish and Game, 1994
{{Taxonbar, from=Q773324

Baja California Rat Snake The Baja California rat snake ''(Bogertophis rosaliae)'' is a species of nonvenomous snake in the family Colubridae. The species is native to Baja California, Mexico; extreme southern California; and some islands in the Sea of Cortés. Descrip ...

Reptiles of Mexico Fauna of the Baja California Peninsula

Fauna of the Colorado Desert Fauna of the Southwestern United States Least concern biota of Mexico Reptiles described in 1899