Black-necked Garter Snake
Thamnophis cyrtopsis cyrtopsis (Western Blackneck garter snake)
Thamnophis cyrtopsis ocellatus (Eastern Blackneck garter snake)
Thamnophis cyrtopsis collaris (Tropical Black-necked garter snake)
Thamnophis cyrtopsis cyrtopsis – USA (southwestern Texas, New Mexico); Mexico (Coahuila).
Thamnophis cyrtopsis ocellatus – South central Texas (Edwards Plateau west to the Big Bend).
Thamnophis cyrtopsis collaris – Mexico (southern Sonora, southeastern Durango, through west and south Mexico to western central Guatemala).
T. c. cyrtopsis – the rocky areas of the canyon rivers. Sometimes one finds this subspecies also in woodland and in dry areas up to 3 km of from water.
T. c. ocellatus – rocky mountain slopes, forested valleys and also in cedar bushes, sometimes far from any water.
T. c. collaris – apparently mainly grassland.
Fish, amphibians, crustaceans/crabs and sometimes also invertebrates.
This species seems to be able to last quite a long time without food in the wild.
Late June to early August, depending on the height at which the animals live, there are between seven and 25 young born. These are about 20 cm long at birth.
This species requires a medium size terrarium. Water bowl does not have to be huge, but big enough for all the snakes to lie in at the same time. Some climbing branches and hiding places must be present.
I keep my pair since 2011 in a semi-transparent plastic box (so-called Curverbox) (60 x 40 x 40 cm WxLxH). Since they live in this “terrarium” they are eating more fanatic and they seem to be more active. In the lid of the box hangs a 25 Watt light bulb (spot).
Fish, amphibians (no native !, but only specially bred …), mice and earthworms can be given as food. Refuses occasionally food during some weeks. This apparently is typically for this species.
For specimen which come from the middle and northern part of the range a brumation of two to four months is recommended.
For the most southern animals it will be sufficient to give them a winter rest of 1 to 2 months (eg. in their own terrarium with heating and lighting off).
Males are on average 50 cm long, and females on average 75 cm. Maximum length up to about 115 cm.
The active period is relatively short for most animals, from March / April to September. From this you can deduce that they will keep a long hibernation; the longer the better. I have brumated my pair 4 months in the refrigerator without problems.
T. c. cyrtopsis lives at altitudes between 300 and 2800 meters.
T. c. ocellatus lives at altitudes up to about 750 meters.
T. c. collaris lives at altitudes around 2000 meters.