Southern rubber boa

Southern rubber boa
Conservation status
Vulnerable  (IUCN 3.1) [1]
Imperiled  (NatureServe) [2]
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Squamata
Suborder:	Serpentes
Family:	Boidae
Genus:	Charina
Species:	C. umbratica
Binomial name
Charina umbratica Klauber, 1943
Southern rubber boa range [3]
Synonyms [4]
Charina bottae umbraticaKlauber, 1943 Charina umbratica — Rodríguez-Robles et al., 2001

Charina umbratica, known commonly as the southern rubber boa, is a species of snake in the family Boidae. ^{[1] [4] [5] [6]} The species is endemic to the United States, in southern California. ^[1]

Taxonomy

The southern rubber boa, also known as Charina umbratica, has been proposed as an independent species because of its morphological and geographic differences. A study published in 2001 concluded that Charina umbratica is separated from its subclade. ^[7] This means that the southern rubber boa and its subclades have allopatric distributions. ^[7] All evidence gathered from the mitochondrial DNA study points to consider Charina umbratic as a distinct species. ^[7] Despite the distinction of the two subclades, a more recent study suggests that grounds for distinction of clades may be invalid as range movements may not be as thoroughly studied and contextualized as previously considered. ^[8]

Conservation status

As of April 2017, the southern rubber boa was listed as a state threatened species in the California Natural Diversity Database. ^[9]

Description

The southern rubber boa is a small snake with a blunt tail. Due to its secretive nature, it makes it very difficult to collect these snakes for data. However, a five-year study done in the San Bernardino Mountains of southern California ^[10] has been able to provide information on this reptile. The study was published in the Journal of Herpetology, and concluded that the female boas' length and weight out-performed the male boas. ^[10] In addition, adult female boas were found to have greater percentages of tail tip scarring and tail shortening when compared to males. Furthermore, this study also explored the weight loss that happens during gestation for female boas and determined that female boas lose 47% of their weight during gestation. ^[10]

Habitat

The southern rubber boa is known to typically inhabit areas such woodlands and coniferous forests characterized by their developed soils and great vegetative productivity. These areas are typically moist and may contain accumulated organic debris that are largely-responsible for the moisture levels of inhabited sites. The southern rubber boa makes use of outcrops, loose and developed soils, as well as tree-debris to burrow and seek refuge. ^{[11] [8]}

Distribution

The southern rubber boa is distributed across the San Bernardino and San Jacinto Mountains east of Los Angeles in southern California, at elevations between 4,900 and 7,900 feet. Phylogenetic analyses have conclusively distinguished northern and southern boas and identified an area in Northeastern California containing populations of both subspecies. ^[7] Some intergrades between northern and southern boas have been located in isolated populations in the Southern Los Padres Ranges. ^{[7] [8]}

Behavior

A five-year study done in the San Bernardino Mountains of southern California analyzed the diet and behavior of the southern rubber boa. This study discussed the behavior of the southern rubber boa and its distinct tendency to eat lizard eggs, rather than the lizards themselves. ^[12] The behavior exhibited from the southern rubber boa to eat the lizard eggs and not the lizard, is what separates the southern rubber boa from other rubber boas. In like manner, this study also found that female boa injuries are primarily received through other animals protecting their young from boa predation. ^[12]

Reproduction

Boas are ovoviviparous – they produce between two and eight young snakes where eggs are hatched within the parent. In April, female boas typically emerge from hibernation under reproductive conditions; mating occurs immediately and persists through May. They give birth between late summer and throughout autumn with a greater majority of young birthed between late August through September. ^{[10] [11]}

Predators

Known predators of the southern rubber boa include kingsnakes (Lampropeltis sp.) and California striped racer (Masticophis lateralis). Other local reptilian predators presumed to prey on the southern rubber boa include ring-necked snakes (Diadophis punctatus) and night snakes (Hypsiglena torquata). ^[12]

References

1. Hammerson, G.A. (2019). "Charina umbratica". IUCN Red List of Threatened Species . 2019: e.T4567A18979867. doi: 10.2305/IUCN.UK.2019-2.RLTS.T4567A18979867.en . Retrieved 20 December 2021.
2. NatureServe (5 May 2023). "Charina umbratica". NatureServe Network Biodiversity Location Data accessed through NatureServe Explorer. Arlington, Virginia: NatureServe. Retrieved 20 May 2023.
3. U.S. Geological Survey (2017). "Southern Rubber Boa (Charina umbratica) rSRBOx_CONUS_2001v1 Range Map". Gap Analysis Project. doi:10.5066/F7MK6BZ1.
4. Charina umbratica at the Reptarium.cz Reptile Database. Accessed 20 December 2021.
5. "Charina umbratica". Integrated Taxonomic Information System . Retrieved 20 December 2021.
6. Banks RC, McDiarmid RW, Gardner AL, Starnes WC (2004). Checklist of Vertebrates of the United States, the U.S. Territories, and Canada.
7. Rodrı́guez-Robles, Javier A; Stewart, Glenn R; Papenfuss, Theodore J (2001). "Mitochondrial DNA-based phylogeography of North American rubber boas, Charina bottae (Serpentes: Boidae)". Molecular Phylogenetics and Evolution. 18 (2): 227–237. Bibcode:2001MolPE..18..227R. doi:10.1006/mpev.2000.0886. PMID   11161758.
8. Stephenson, John R.; Calcarone, Gena M. (1999). Southern California Mountains and Foothills Assessment: Habitat and Species Conservation Issues (Report). General Technical Report. Vol. GTR-PSW-172. Albany, CA: Pacific Southwest Research Station, Forest Service, U.S. Department of Agriculture. p. 402. doi: 10.2737/PSW-GTR-172 .
9. California, State of. "Threatened and Endangered Reptiles - California Department of Fish and Wildlife". www.dfg.ca.gov. Retrieved 2017-05-12.
10. Hoyer, Richard F.; Stewart, Glenn R. (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 (3): 348–354. doi:10.2307/1565355. JSTOR   1565355.
11. Stebbins, Robert C.; McGinnis, Samuel M. (2019-07-01). Field Guide to Amphibians and Reptiles of California. doi:10.1525/9780520949973. ISBN   9780520949973. S2CID   242392961.
12. Hoyer, Richard F.; Stewart, Glenn R. (2000). "Biology of the rubber boa (Charina bottae), with emphasis on C. b. umbratica. Part II: Diet, antagonists, and predators". Journal of Herpetology. 34 (3): 354–360. doi:10.2307/1565356. JSTOR   1565356.

Further reading

• Klauber LM (1943). "The Subspecies of the Rubber Snake, Charina ". Trans. San Diego Soc. Nat. Hist.10 (7): 83–90. (Charina bottae umbratica, new subspecies, pp. 83–85).
• Rodríguez-Robles, Javier A.; Stewart, Glenn R.; Papenfuss, Theodore J (2001). "Mitochondrial DNA-Based Phylogeography of North American Rubber Boas, Charina bottae (Serpentes: Boidae)". Molecular Phylogenetics and Evolution18 (2): 227–237.