Chihuahuan night snake (Hypsiglena jani)
The Chihuahuan night snake is a snake in the family Colubridae with a mild venom for its prey, not dangerous to people. GBIF holds 746 licensed U.S. records of it; it reaches our listing threshold in 6 states, most of all Texas (589), Oklahoma (83) and New Mexico (41). Its observation records peak in June.
Hypsiglena jani, commonly known as the Texas night snake or the Chihuahuan night snake, is a small species of mildly venomous snake in the subfamily Dipsadinae of the family Colubridae. The species is native to the southwestern United States and adjacent northeastern Mexico.
From Wikipedia: Hypsiglena jani, text under CC BY-SA 4.0.
Is the Chihuahuan night snake poisonous or venomous?
Mildly venomous but not dangerous: the Chihuahuan night snake has enlarged rear teeth and a mild venom for its prey, and a bite causes at most local swelling, which is why many sources simply call it harmless. It is not a pit viper or coral snake, the only U.S. land snakes with medically dangerous venom. Clean any bite like a small wound.
Which states have the Chihuahuan night snake?
The Chihuahuan night snake's U.S. record is concentrated: Texas alone holds 79% of licensed records. It is listed in 6 states in all; the next are Oklahoma (83), New Mexico (41) and Kansas (27).
The count includes 14 records filed under the older name Hypsiglena ochrorhynchus in Texas and 359 records filed under the older name Hypsiglena torquata in Kansas (18), Oklahoma (14) and Texas (327).
| # | State | Records | Share of state snakes | Rank in state |
|---|---|---|---|---|
| 1 | Texas | 589 | 1.4% | 22nd of 86 |
| 2 | Oklahoma | 83 | 0.6% | 31st of 50 |
| 3 | New Mexico | 41 | 0.6% | 25th of 56 |
| 4 | Kansas | 27 | 0.2% | 38th of 44 |
| 5 | Arizona | 5 | 0.0% | 59th of 60 |
| 6 | Colorado | 1 | 0.0% | 26th of 26 |
When is the Chihuahuan night snake seen?
Across the U.S., observation records of the Chihuahuan night snake run mostly April through September, peaking in June with 40% of them. Almost none are from December to February.
Where the Chihuahuan night snake is recorded in each state
Texas
Texas holds 589 licensed records, the 22nd most recorded of 86 snakes listed there. Its observation records in Texas run mostly April through September, peaking in June; most licensed records come from Brewster County, Val Verde County and El Paso County. Next come Presidio County (37) and Hudspeth County (33).
Oklahoma
Oklahoma holds 83 licensed records, the joint 31st most recorded of 50 snakes listed there. Most of its licensed records in Oklahoma come from Beckham County, Comanche County and Greer County. Next come Ellis County (6) and Harmon County (6).
New Mexico
New Mexico holds 41 licensed records, the 25th most recorded of 56 snakes listed there. Most of its licensed records in New Mexico come from Hidalgo County, Doña Ana County and Otero County. Next come Sierra County (4) and Socorro County (2).
Top counties in the U.S.
| # | County | State | Records | Share of U.S. |
|---|---|---|---|---|
| 1 | Brewster County | Texas | 137 | 18.4% |
| 2 | Val Verde County | Texas | 41 | 5.5% |
| 3 | El Paso County | Texas | 38 | 5.1% |
| 4 | Presidio County | Texas | 37 | 5.0% |
| 5 | Hudspeth County | Texas | 33 | 4.4% |
| 6 | Beckham County | Oklahoma | 21 | 2.8% |
| 7 | Jeff Davis County | Texas | 19 | 2.5% |
| 8 | Comanche County | Oklahoma | 16 | 2.1% |
| 9 | Greer County | Oklahoma | 16 | 2.1% |
| 10 | Hidalgo County | New Mexico | 13 | 1.7% |
| 11 | Culberson County | Texas | 12 | 1.6% |
| 12 | Tom Green County | Texas | 11 | 1.5% |
| 13 | Garza County | Texas | 11 | 1.5% |
| 14 | Denton County | Texas | 10 | 1.3% |
| 15 | Doña Ana County | New Mexico | 9 | 1.2% |
How recent are the Chihuahuan night snake records?
The Chihuahuan night snake record leans on older material: only 7% of dated U.S. records come from 2017–2026, and the median record is from 1980. The oldest dated record is from 1894; the busiest year was 1968, with 33 records.
| Decade | Records | Share |
|---|---|---|
| 1890s | 1 | 0.1% |
| 1900s | 1 | 0.1% |
| 1910s | 2 | 0.3% |
| 1920s | 3 | 0.4% |
| 1930s | 15 | 2.2% |
| 1940s | 17 | 2.5% |
| 1950s | 83 | 12.1% |
| 1960s | 123 | 17.9% |
| 1970s | 95 | 13.8% |
| 1980s | 65 | 9.4% |
| 1990s | 62 | 9.0% |
| 2000s | 73 | 10.6% |
| 2010s | 118 | 17.2% |
| 2020s | 30 | 4.4% |
Species recorded in the same counties
Of the 104 counties where the Chihuahuan night snake is most recorded, 66 are also top counties for the gopher snake, more than for any other snake. Venomous species among its neighbors: the western massasauga and the western diamondback rattlesnake.
| Species | Shared counties |
|---|---|
| Gopher snake | 66 |
| Western massasauga venomous | 34 |
| Long-nosed snake | 32 |
| Plains black-headed snake | 32 |
| Glossy snake | 30 |
| Western ground snake | 27 |
| Western diamondback rattlesnake venomous | 26 |
| Coachwhip | 25 |
Related species in the U.S.
Other members of the family Colubridae with profiles here: Western terrestrial garter snake, Common garter snake, Gopher snake, Ring-necked snake, Northern water snake and Eastern racer.
GBIF records read 2026-09-29. Listed: any license. Counted: CC0/CC BY only. How we count.