Thamnophis atratus
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Santa Cruz Garter Snake ( Thamnophis atratus atratus ) |
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| Thamnophis atratus | ||||||||||||
| ( Kennicott , 1860) |
Thamnophis atratus is a species of snake from the genus of the garter snake ( Thamnophis ).
features
Thamnophis atratus is one of the larger garter snakes with a maximum length of 60 cm to just over a meter. The basic color is very variable and ranges from light gray to dark brown to black. Two alternating rows of black spots on the flanks are easily or barely visible, depending on the basic color. There is a wide, light yellow or orange stripe on the back. Another, light yellow stripe runs along each flank on the second or third row of back scales. Back and / or side stripes can also be missing. The ventral side is blue, green, yellow or white. The upper lip scales are light yellow, there are 19 to 21 rows of scales in the middle of the trunk.
Occurrence and way of life
The species inhabits oak forests, grasslands and chaparrals in the western United States in the states of Oregon and California . It occurs preferentially near water and in places with the possibility of sunbathing and inhabits heights of up to 1900 meters.
Young animals lurk in hiding , mainly near the banks of still waters for prey, while older animals actively hunt and prefer the banks of fast flowing waters or deeper water. The main prey is the tadpoles of frogs and toads, as well as small fish and salamanders. Young animals have been observed to lure fish at the water's edge by touching the water surface with their tongues several times longer and thus probably imitating an insect wriggling in the water.
The mating takes place from March to April, rarely later, the young are born alive from August to mid-October . Some populations take a brief winter hiatus while animals in central California are active year round.
Subspecies
Three subspecies are currently recognized:
- Santa Cruz garter snake ( Th. Atratus atratus ( Kennicott , 1860 )) - Squat; Basic color blue to light green, never light gray; Dorsal stripes light and distinct, side stripes sometimes absent; with light yellow throat; Ventral side with red to orange spots; in the outer coastal area of the peninsula of San Francisco .
- Oregon Garter Snake ( Th. Atratus hydrophilus Fitch , 1936 ) - Slimmer; with strong or weak or rarely absent back stripes, flank stripes strong, dull or absent; many small, black spots on the back; Ventral side light yellow to white and unspotted; north of San Francisco Bay .
- Diabolo garter snake ( Th. Atratus zaxanthus Boundy , 1999 ) - Squat; Back and side stripes light up yellow or flank stripes pale green, light yellow throat; Belly pale; in the south of the range from San Francisco to Santa Barbara .
swell
- Martin Hallmen, Jürgen Chlebowy: Garter Belt Adders . Natur und tier-Verlag, Münster 2001, ISBN 3-931587-49-5 .
- 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 . tape 48 , 1994, pp. 1261-1273 (English, 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 . tape 51 , no. 6 , 1999, p. 311-336 (English).
Web links
- Photos on californiaherps.com
- Thamnophis atratus in The Reptile Database
- Thamnophis atratus onthe IUCN 2013 Red List of Threatened Species . Listed by: Hammerson, GA, 2007. Retrieved September 16, 2013.
Individual evidence
- ↑ Hartwell H. Welsh, Jr, Amy J. Lind: Evidence of Lingual-luring by an Aquatic Snake . In: Journal of Herpetology . tape 34 , no. 1 , 2000, pp. 67–74 (English, online (pdf) ).