Scientific name:
Thamnophis scalaris
Dutch name:
Mexicaanse gevlekte bergkousebandslang
English name:
Mexican alpine blotched garter snake/Longtail alpine garter snake
German name:
Treppen-Strumpfbandnatter

Subspecies:
None

Pictures of Thamnophis scalaris…

Range:
Along the Transverse Volcanic Axis of central Mexico, from central Jalisco to Veracruz (Federal Districts, Guanajuato, Jalisco, Michoacán, Oaxaca, Querétaro, Tamaulipas and Veracruz).

Habitat:
The coniferous forests that are situated high in the mountains. Was found on a grassy, steep mountainside, near and below stones.

Food:
Worms, amphibians, lizards and rodents. In a few cases also snakes (see specifics for details).

Reproduction:
There are only two known cases.
Both cast took place in the 2nd half of May. One litter contained 8 snakes and the other 15. They were 17-18 cm long.

Terrarium:
Only known to, apparently, react very unfavourable if the terrarium is too moist.
No further details are known.

Specifics:
Length up to 50 cm.
Occurs at altitudes between 2100 and 4300 meters.
Has, for Thamnophis, an unique hemipenis. It is very long and thin. The average length is about 27 subcaudals when it lies in the tail.
There is one known case of this species that it ate a young Crotalus triseriatus (Mexican dusky rattlesnake). (Manjarrez et al 2007. Southwest Nat 52: 258-262)
Another case of Thamnophis scalaris has eaten a snake is described by Mociño–Deloga et al. They caught an adult male and this regurgitated “voluntarily” an adult male of the species Thamnophis scaliger. The T. scalaris had body length of 483 mm and an tail length of 102 mm (missing the tip); the weight was, after the regurgitation, 67 grams. The regurgitated T. scaliger had body length of 363 mm and a tail length of 93 mm; the weight was 32.3 grams, taking into account that 10-15% of the snake had been digested.
The T. scaliger was devoured with the head first.
The T. scalaris was caught at Acambay, Estudo de México, Mexico (19.863 °N, 99.803 °W) at a hight of 2720 metres.
The caught snake is later released at the finding place. (Mociño-Deloya et al., Herpetological Review 40 (4), 2009).

Observations