San Francisco garter snake
Conservation status
Endangered
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Reptilia Order: Squamata Suborder: Serpentes Family: Colubridae Genus: Thamnophis Species: T. sirtalis Subspecies: T. s. tetrataenia
Trinomial name
Thamnophis sirtalis tetrataenia Cope, 1875

The San Francisco garter snake (Thamnophis sirtalis tetrataenia) is a slender multi-colored colubrid snake. Designated as an endangered species since the year 1967,^[1] it resides only in San Mateo County, California and the extreme northern part of coastal Santa Cruz County, California. There are only 1,000 to 2,000 of the subspecies T. s. tetrataenia remaining. This garter snake prefers wet and marshy areas and is elusive to see or capture. It is a subspecies of the common garter snake (Thamnophis sirtalis): a species found across the United States and into southern Canada. Image File history File links SFGS_FWS.jpg‎ This image was made for and by an agency of the United States Government: the U.S. Fish and Wildlife Service It is correspondingly in the public domain property of us govt, us fish and wildlife service photo This image was made for... The conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. ... Image File history File links Status_iucn3. ... The critically endangered Amur Tiger, a rare subspecies of tiger. ... For other uses, see Scientific classification (disambiguation). ... Animalia redirects here. ... Typical Classes See below Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates. ... Subclasses Anapsida Diapsida Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane. ... Suborders Lacertilia- Lizards Serpentes - Snakes Amphisbaenia - Worm lizards This article is about the Squamata order of reptiles. ... Families Acrochordidae Aniliidae Anomalepididae Anomochilidae Atractaspididae Boidae Bolyeriidae Colubridae Cylindrophiidae Elapidae Hydrophiidae Leptotyphlopidae Loxocemidae Pythonidae Tropidophiidae Typhlopidae Uropeltidae Viperidae Xenopeltidae Snakes are cold blooded legless reptiles closely related to lizards, which share the order Squamata. ... Genera According to ITIS: Adelophis Adelphicos Alsophis Amastridium Arizona Arrhyton Atractus Bogertophis Boiga Carphophis Cemophora Cerberus Chersodromus Chilomeniscus Chionactis Clelia Clonophis Coluber Coniophanes Conophis Conopsis Contia Cryophis Dendrelaphis Dendrophidion Diadophis Dipsas Dryadophis Drymarchon Drymobius Elaphe Enulius Eridiphas Erythrolamprus Farancia Ficimia Geagras Geophis Gyalopion Heterodon Hypsiglena Imantodes Lampropeltis Leptodeira Leptophis Liochlorophis... Species many — see text A garter snake, or garden snake, or gardner snake, is any species of North American snake within the genus Thamnophis. ... Binomial name Thamnophis sirtalis Linnaeus 1758 The Common Garter Snake (Thamnophis sirtalis) is, as the name suggests, quite common in North America. ... Trinomial nomenclature is a taxonomic naming system that extends the standard system of binomial nomenclature by adding a third taxon. ... Edward Drinker Cope Edward Drinker Cope (July 28, 1840–April 12, 1897) was an American paleontologist and comparative anatomist. ... 1875 (MDCCCLXXV) was a common year starting on Friday (see link for calendar). ... Subfamilies Boodontinae Calamariinae Colubrinae Dipsadinae Homalopsinae Natricinae Pareatinae Psammophiinae Pseudoxenodontinae Pseudoxyrhophiinae Xenodermatinae Xenodontinae See text for genera. ... For other uses, see Snake (disambiguation). ... The critically endangered Amur Tiger, a rare subspecies of tiger. ... Official website: http://www. ... Santa Cruz County is a county located on the Pacific coast of the U.S. state of California, just south of the San Francisco Bay Area, it forms the northern coast of the Monterey Bay. ... In zoology, as in other branches of biology, subspecies is the rank immediately subordinate to a species. ... The Common Garter Snake (Thamnophis sirtalis) is common in North America. ...

Description

The San Francisco garter snake presents a burnt orange head, greenish-yellow dorsal stripe edged in black, bordered by a red stripe, which may be continuous or broken with black blotches, below which is a black side stripe. Pigmentation of the underside ranges from greenish-blue to blue. Large adults can attain a length of one meter. The scales are keeled. Dorsal scales appear in 19 rows at maximum, whereas the other species of garter snake in the region (Thamnophis elegans and Thamnophis atratus) can range up to 21 scale rows ^[2]. There is a single anal plate. There are seven upper lip scales. The side stripe is confined to the second and third tier scales. Distinguishing this species from other garter snakes are red markings between its dorsal and side stripes, yielding the appearance of a wide continuous stripe.^[3] If captured it thrashes about wildly, may bite, and smears its captor with excrement and odorous fluids from the anal scent glands. The colour orange occurs between red and yellow in the visible spectrum at a wavelength of about 585–620 nanometres. ... For other uses, see Green (disambiguation). ... Yellow is any color of light that stimulates both the red and green cone cells of the retina, but not the blue cone cells. ... Unlucky black cat. ... Red may be any of a number of similar colours at the lowest frequencies of light discernible by the human eye. ... The term Blue may refer any of a number of similar colours. ... In most biological nomenclature, a scale (Greek lepid, Latin squama) is a small rigid plate that grows out of an animals skin to provide protection. ... Species Many; see article. ... In anatomy, the dorsum is the upper or back side of an animal, as opposed to the ventrum. ... Anal can mean: Anus, the external opening of the rectum Anal retentive, a person overly uptight or distressed over ordinarily minor problems Anal sex, anal sexual intercourse This is a disambiguation page, a list of pages that otherwise might share the same title. ... This article needs to be cleaned up to conform to a higher standard of quality. ...

Wetland habitat of the San Francisco garter snake in Millbrae, California

Image File history File linksMetadata Download high-resolution version (2816x2112, 1139 KB) i took this photo and release all rights to wikipedia I, the creator of this work, hereby release it into the public domain. ... Image File history File linksMetadata Download high-resolution version (2816x2112, 1139 KB) i took this photo and release all rights to wikipedia I, the creator of this work, hereby release it into the public domain. ... A subtropical wetland in Florida, USA, with an endangered American Crocodile. ... Habitat (from the Latin for it inhabits) is the place where a particular species lives and grows. ... General view of Millbrae Millbrae is a city in San Mateo County, California, United States. ...

Range and habitat

This subspecies of garter snake is found in scattered wetland areas on the San Francisco Peninsula from approximately the northern boundary of San Mateo County south along the eastern and western bases of the Santa Cruz Mountains, at least to the Upper Crystal Springs Reservoir, and along the Pacific coast south to Año Nuevo Point, and thence to Waddell Creek in Santa Cruz County.^[4] It is difficult to obtain reliable distribution information and population statistics for the San Francisco garter snake, because of the elusive nature of this organism and the fact that much of the remaining suitable habitat is located on private property that has not been surveyed for the presence of the snake. This subspecies is extremely shy, difficult to locate and capture, and quick to flee to water or cover when disturbed. The U.S. Fish and Wildlife Service has stated that many locations that previously had healthy populations of garter snakes are now in decline due to land development pressure and the filling of wetlands in San Mateo County over the last sixty years. This snake is also a rare species in addition to its endangered classification. The Santa Cruz Mountains, part of the Pacific Coast Ranges, are a mountain range in central California. ... Pacific redirects here. ... The USFWS logo The United States Fish and Wildlife Service is a unit of the United States Department of the Interior that is dedicated to managing and preserving wildlife. ... A subtropical wetland in Florida, USA, with an endangered American Crocodile. ... Rare species is an organism which is very uncommon or scarce. ...

The snake’s preferred habitat is a densely vegetated pond near an open hillside where it can sun, feed, and find cover in rodent burrows; however, markedly less suitable habitat can be successfully used. Temporary ponds and other seasonal freshwater bodies are also appropriate. This subspecies avoids brackish marsh areas because its preferred prey, the California red-legged frog (Rana aurora) cannot survive in saline water. Emergent and bankside vegetation such as cattails, (Typha spp.), bulrushes (Scirpus spp.) and spike rushes (Juncus spp. and Eleocharis spp.) apparently are preferred and used for cover.^[5] The zone between stream and pond habitats and grasslands or bank sides is characteristically utilized for basking, while nearby dense vegetation or water often provide escape cover. The subspecies occasionally uses floating algal or rush mats, when available. Habitat (from the Latin for it inhabits) is the place where a particular species lives and grows. ... Suborders Sciuromorpha Castorimorpha Myomorpha Anomaluromorpha Hystricomorpha Rodentia is an order of mammals also known as rodents. ... There is a suggestion that the words Bunny and Burrow have a common origin and meaning, French in origin appearing in Britain afetr the Norman conquest. ... A pond is typically a body of water smaller than a lake. ... For the village on the Isle of Wight, see Freshwater, Isle of Wight. ... Brackish water is water that is saltier than fresh water, but not as salty as sea water. ... Freshwater marsh in Florida In geography, a marsh is a type of wetland, featuring grasses, rushes, reeds, typhas, sedges, cat tails, and other herbaceous plants (possibly with low-growing woody plants) in a context of shallow water. ... Prey can refer to: Look up Prey in Wiktionary, the free dictionary A prey animal eaten by a predator in an act called predation. ... Binomial name Rana draytonii The California Red-legged frog (Rana draytonii) is a species of frog within the family Ranidae also known as the true frogs. // Physical description The California Red-legged Frog is a moderate to large (4. ... Saline may refer to: Salinity Saline (medicine) Saline, Michigan Saline, Scotland - a village in the burgh of Fife, Scotland. ... Species See text. ... Species See text. ... The term bulrush (or sometimes as bullrush) typically refers to tall, herbaceous plants that grow in wetlands. ... Species About 120; see text The plant genus Scirpus consists of a large number of aquatic, grass-like species in the family Cyperaceae (the sedges), many with the common names club-rush or bulrush (see also bulrush for other plants so-named). ... Species see text Juncus is a genus of the Juncaceae family. ... A running stream. ... A pond is typically a body of water smaller than a lake. ... Grasslands are very generally open and continuous, fairly flat area of grass. ... The algae (singular is alga) comprise several different groups of living things that produce energy through photosynthesis. ...

San Francisco garter snakes forage extensively in aquatic habitats. Adult snakes feed primarily on California red-legged frogs, which is federally listed as endangered. They may also feed on juvenile bullfrogs (Rana catesbeiana), but they are unable to consume adults; in fact, adult bullfrogs prey on juvenile garter snakes, and may be a contributing factor in the population decline of the San Francisco garter snake. Newborn and juvenile San Francisco garter snakes depend heavily upon Pacific treefrogs (Hyla regilla) as prey. If newly metamorphosed Pacific treefrogs are not available, the young garter snakes may not survive. San Francisco garter snakes are one of the few animals capable of ingesting the toxic California newt (Taricha torosa) without incurring sickness or death. An aquatic ecosystem is an ecosystem that is based in water, whether it is a pond, lake, river, underground water body, estuary or ocean. ... Juvenile (left) and adult (right) leaves of Stone Pine A juvenile is an individual organism that has not yet reached its adult form, sexual maturity or size. ... Binomial name Rana catesbeiana Shaw, 1802 Bullfrog range The American Bull Frog (Rana catesbeiana) is an aquatic frog, a member of the family Ranidae, or true frogs, native to much of North America. ... Binomial name Pseudacris regilla (Baird & Girard, 1852) Synonyms Hyla regilla The Pacific Tree Frog (Pseudacris regilla formerly Hyla regilla) is a small (2. ... Toxic redirects here, but this is also the name of a song by Britney Spears; see Toxic (song) Look up toxic and toxicity in Wiktionary, the free dictionary. ... Binomial name Taricha torosa // Subspecies Species torosa is divided into two subspecies: Sierra newt (Taricha torosa sierrae) Costal Range newt (Taricha torosa torosa). ...

Life cycle

Adult snakes sometimes estivate (enter a dormant state) in rodent burrows during summer months when ponds dry. Along the Pacific Ocean coast, snakes hibernate during the winter, but further inland, if the weather is suitable, this species is known to be active year-round. Recent studies have documented San Francisco garter snake movement over several hundred meters from wetlands to hibernate in upland small mammal burrows. In spite of being primarily diurnal, captive specimens housed in an exterior setting were observed foraging nocturnally or crepuscularly on warm evenings. Estivation or aestivation (from Latin aestas, summer) is a state of dormancy similar to hibernation. ... Suborders Sciuromorpha Castorimorpha Myomorpha Anomaluromorpha Hystricomorpha Rodentia is an order of mammals also known as rodents. ... Hibernation is a state of inactivity and metabolic depression in animals, characterized by lower body temperature, slower breathing, and lower metabolic rate, to conserve energy, especially during winter. ... A diurnal animal (dī-ŭrnəl) is an animal that is active during the daytime and sleeps during the night. ... A bat illustrating nocturnal features. ... This article or section does not cite its references or sources. ...

The San Francisco garter snake mates in the spring or autumn, and the females give birth to live young in June through September, numbering up to two dozen, but averaging about 16 offspring. The young are approximately 12 to 18 centimeters in length and mature in two years time.

Taxonomy and relation to other garter snakes

For a brief period from 1996 to 2000 there was confusion over the differentiation of the San Francisco garter snake from two other subspecies, known as the red-sided garter snake (T. s. infernalis) and the red-spotted garter snake (T. s. concinnus). Barry petitioned ^[6] the International Commission on Zoological Nomenclature (ICZN) to suppress the changes proposed in 1996 to merge two of these species. In 2000, the ICZN agreed and voted to retain the historical taxonomic arrangement of subspecies within this evolutionary lineage. Accordingly, the subspecies tetrataenia was reaffirmed for the San Francisco garter snake and the races concinnus and infernalis retain their historical definition. The International Code of Zoological Nomenclature is a set of rules in zoology that have one fundamental aim: to provide the maximum universality and continuity in classifying all animals according to taxonomic judgment. ... Look up taxonomy in Wiktionary, the free dictionary. ...

Don Roberson has noted the following analysis regarding food competition among several garter snakes. The San Francisco garter snake cohabits ecosystems that host two other species of garter snake: the coast garter snake (Thamnophis elegans terrestris), a subspecies of western terrestrial garter snake (T. elegans), and the Santa Cruz aquatic garter snake (Thamnophis atratus atratus) a subspecies of the aquatic garter snake (T. atratus). These three subspecies are known to prey upon same foods; however, their preferences are slightly different. Herpetologist Sean Barry notes that they divide up the food resource as follows:

• The San Francisco garter snake eats primarily small frogs;
• The coast garter snake eats principally slugs, and
• The Santa Cruz aquatic garter snake eats preferentially minute fish and amphibian larvae.

DNA analysis

While the findings of the ICZN have given the San Francisco garter snake unique taxonomic standing for now, a molecular study challenges the subspecific status of this population. Janzen ^[7] analyzed sequences in mitochondrial DNA to determine relationships within the common garter snake (T. sirtalis). Janzen found that molecular evidence differed, often sharply, with the territorial boundaries of subspecies named on phenotypic variation. He further deduced that local environmental forces were more significant in shaping the color patterns shown by the garter snakes than shared common ancestry, and concluded all morphologically based subspecies in the western U.S. to be subject to revision. This result strongly suggests that the color traits that are diagnostic for (T.s. tetrataenia) are the result of local selection rather than long-term isolation from other races of (T. sirtalis) in central California. ...

Don Roberson points out that In the San Francisco Bay Area, there is a group of three populations of T. s. infernalis in Sonoma County, Contra Costa County, and Santa Clara County formed a divergent diagnosable group that exhibited an "elevated rate of molecular evolution". Roberson notes that these three populations are a mere 25 to 125 kilometers from tetrataenia in San Mateo County and yet genetic distinctness is readily apparent." Roberson also points out that sequencing nuclear DNA may provide a more precise analytical tool to crack some of the ultimate taxonomic quandaries of the San Francisco garter snake and its relatives. Sonoma County is a county located on the Pacific coast of the U.S. state of California, north of Marin County and the San Francisco Bay Area. ... Official website: http://www. ... Location of Santa Clara County within California. ... Nuclear DNA is DNA contained within a nucleus of eukaryotic organisms. ...

Outlook for this subspecies

Many of the factors that led to the listing of the San Francisco garter snake in 1967 continue to impact the organism. These environmental elements include loss of habitat from agricultural, commercial and urban development as well as collection by reptile fanciers and breeders.^[8] One of the largest populations of this species is located immediately west of the San Francisco International Airport and has been studied in relation to airport and airport infrastructure expansion plans.^[9] These studies have led to guidelines for land development and habitat mitigation to maximize the likelihood of species survival. Ironically, morphological data suggest that the airport population is made up of hybrid individuals. ^[10] In September 2001, the accidental death of a single garter snake at the construction site delayed construction efforts 18 days and cost $1.07 million dollars. ^[11] FAA diagram of SFO SFO redirects here. ...

External links

• Further reading on the San Francisco garter snake
• Fact sheet from Woodland Park Zoo
• San Francisco Zoo fact sheet

References