NIGHT SNAKE (Hypsiglena torquata)
The night snake is RED-listed. It is considered to be at risk in B.C. because very few occurrences are known and most of these are from a rapidly developing portion of the province, south Okanagan and Similkameen valleys.
The night snake is a secretive nocturnal snake that occurs in a variety of semiarid habitats throughout Mexico and the western United States. In B.C., it occurs in the shrub-steppe habitats of the Okanagan and Similkameen valleys up to 945 m, but most occur around 450 m. Generally, this species is found in close association with talus and rock outcrops. Since the majority of records in B.C. are from rocky areas and several of these records were recorded late in the season, when other species are denning, it is likely that denning occurs in rock fissures or talus slopes. In B.C., night snakes have been found to den communally with other species, such as the western rattlesnake (Crotalus virdis). Denning occurs between October and May. Mating occurs at the time snakes emerge from the hibernacula. Eggs are laid in June or July within the summer range, which probably does not extend far (<1 km) from the hibernacula. Summer foraging habitat is most likely talus slopes, rock outcrops, and nearby ravines and riparian areas. Generally, this species preys on amphibians and other reptiles, which it disables with a weak venom. Its venom is not considered dangerous to humans.
SOI: SOB, OKR, NOB, possibly SOH
BG: BGxh1
PP: PPxh1
AB, AC, BS, CL, CR, PP, RO, SS, TA
1: non-vegetated/sparse
2: herb
3: shrub/herb
Talus and rock outcrops are the most critical habitat features as they provide suitable hibernating sites, cover and support prey.
B.C. Ministry of Environment. 1993. Report on the status of the Night Snake
(Hypsiglena torquata) in British Columbia. B.C. Min. Environ., Lands and Parks, Wildl. Br., Victoria, B.C.
Sarell, M.J. 1993. Snake Hibernacula in the South Okanagan. Unpubl. report prepared for
B.C. Min. Environ., Lands and Parks, Penticton, B.C.
Shewchuk, C.H. and P.T. Gregory. [1994]. Methods for sampling snakes in British
Columbia. B.C. Min. Environ., Lands and Parks, Victoria, B.C. (In press).
