Aquatic garter snake

Santa Cruz garter snake ( Thamnophis atratus atratus )

Thamnophis atratus is a species of snake in the genus of garter snakes ( Thamnophis ).

Features

Thamnophis atratus part with a maximum length of 60 cm to just over a meter to the larger garter snakes. The basic color is highly variable, ranging from light gray to dark brown to almost black. Two alternating rows of black spots on the flanks are subject well or barely visible from the ground color. On the back, a broad pale yellow or orange stripe runs. Another, bright yellow stripe running along each edge on the second or third dorsal scale row. Back and / or side panels can also be absent. The belly is blue, green, yellow or white. The upper lip scales are light yellow, lying at the middle of the fuselage in front of 19 to 21 scale rows.

Occurrence and life

The species colonized oak forests, grasslands and chaparral in the western U.S. in the states of Oregon and California. It occurs preferably in the vicinity of water, and in places with sunbathing facilities and inhabited altitudes up to 1900 meters.

Young animals lurking in hiding, mostly near the shore silent waters for prey, while older animals actively hunt and for the banks prefer fast-flowing waters or deeper water. When prey are mainly the tadpoles of frogs and toads, as well as small fish and salamanders. Juveniles were being watched at the water's edge to attract fish by several times longer hit the water with his tongue and as likely mimic a wriggling in the water insect.

Mating occurs from March to April, rarely later instead, the young are born alive from August to mid-October. Some populations insert a short winter break, while the animals are active year-round in Central California.

Subspecies

Currently three subspecies are recognized:

  • Santa Cruz Garter Snake ( T. atratus atratus ) Kennicott, 1860 - Squat; Basic color blue to light green, never light gray; Back strip bright and clear stripes on the flanks sometimes missing; with light yellow throat; Ventral side with red to orange spots; in the outer coastal areas of the peninsula of San Francisco.
  • Oregon Garter Snake ( T. atratus hydrophilus ) Fitch, 1936 - Slim; vigorously with strong or weak or rarely distinct lack of spine strip, edge strip, dull or absent; many small black spots on the back; Belly pale yellow to white and unspotted; north of the bay of San Francisco.
  • Diabolo garter snake ( T. atratus zaxanthus ) Boundy, 1999 - Squat; Back and side strip light yellow or pale green stripes on the flanks, bright yellow throat; Belly pale; in the south of the range from San Francisco to Santa Barbara.

Swell

  • Martin Hallmen, Jürgen Chlebowy: Garter snakes. Nature and animal -Verlag, Münster 2001, ISBN 3931587495th
  • Douglas Athon Rossman, Neil B. Ford, Richard A. Seigel: The Garter Snakes - Evolution and Ecology. University of Oklahoma Press, 1996, ISBN 978-0-8061-2820-7.
  • Amy J. Lind, Hartwell H. Welsh, Jr: Ontogenetic changes in foraging behavior and habitat use by the Oregon garter snake, Thamnophis atratus hydrophilus. In: Animal Behavior. 48, 1994, pp. 1261 to 1273 (PDF).
  • Jeff Boundy: Systematics of the Garter Snake Thamnophis atratus at the Southern End of Its Range. In: Proceedings of the California Academy of Sciences. 51, No. 6, 1999, pp. 311-336.
San Francisco Bay Santa Barbara, California
235090
de