San Francisco Garter snake (Thamnophis sirtalis tetrataenia) is a multicolored colubrid snake and known to be the most beautiful serpent in North America and one of the most endangered snake species throughout the world since the year 1967. Researchers estimates a total population of only 1,000 to 2,000 adult snakes remaining in the wild; of which this snakes prefers wet and marchy areas and is elusive to see or capture. Known to be endemic to California and resides only in San Mateo County, California and some extreme northern part of coastal Santa Cruz County, California. It is a nonvenomous snake. It has toxins in their saliva which can be deadly to their prey and their bite might produce an unpleasant reaction in humans yet are not considered to be dangerous.
Adults measure 18-55 inches in length but average size is less than 36 inches. It is a medium-sized snake with a head barely wider than the neck and keeled dorsal scales. A wide blue-green or greenish yellow dorsal stripe is bordered with black stripes. Below the black stripe is a continuous red stripe, bordered below by another black stripe. Below that is a bluish or greenish yellow lateral stripe. There may also be a thin line of black below the lateral stripe on the edge of the belly. The underside is bluish-green. Occasionally, the red stripes may be broken with black, similar to T. s. infernalis. The head is red, with eyes that are relatively larged compared with other gartersnake species.
This species of snake forage extensively in aquatic habitats and adult snakes feed primarily on California red-legged frogs which are also listed as threatened. They also feed on juvenile bullfrogs and most of the snake’s newborn and juveniles depend so much on the Pacific treefrogs as prey. And if no treefrogs available the younger snakes may not survive.Loss of habitat due to agricultural, commercial and urban development as well as collection by reptile fanciers and breeders are just few of the contributing factors to the decline of the population of the San Francisco Garter snake. Collection of these endangered animals by private citizen remains to be illegal.
