Hypsiglena chlorophaea
Silhouette: Jose Carlos Arenas-Monroy · PhyloPic
In 3 days ~30% in a week ~60%
Hypsiglena chlorophaea, commonly known as the desert nightsnake, is a species of rear-fanged colubrid snake native to North America. It is found throughout regions of Mexico, the United States, and in a small, isolated population in British Columbia, Canada. Known for its highly secretive, nocturnal nature, it is a mildly venomous species that poses no danger to humans.
The desert nightsnake is a small, slender snake, typically measuring between 30 and 66 cm (12 to 26 inches) in total length. Females are generally longer and heavier than males. Its base coloration ranges from beige or yellowish to grey, overlaid with dark grey-brown blotches that usually form offset pairs down its back. It has three distinct, elongated dark blotches on its neck and behind each eye.
Because of its triangular-shaped head, vertical pupils, and blotched patterning, it is frequently mistaken for a juvenile rattlesnake. However, the desert nightsnake lacks a rattle and possesses smooth dorsal scales. It is an opisthoglyphous (rear-fanged) snake, meaning its enlarged, grooved teeth are located at the back of the upper jaw to help subdue prey.
The desert nightsnake has three... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Saguaro National Park | 🇺🇸 United States | |
| 2 | Death Valley National Park | 🇺🇸 United States | |
| 3 | Zion National Park | 🇺🇸 United States | |
| 4 | Grand Canyon National Park | 🇺🇸 United States | |
| 5 | Joshua Tree National Park | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Desert Nightsnake sighting in Saguaro National Park on a given day, based on 43 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 25th most-seen of the 51 reptiles we can rate there. Over three days the chance rises to about 30%, and over a week to about 60%, if each day is a fresh chance.
July–August and October
In those months about 20% of wildlife watchers report a Desert Nightsnake in Saguaro National Park on a given day, against under 5% in December to March, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Desert Nightsnake sightings with a recorded time, and about 8 in 10 of them come between 6 pm and 6 am: it is mostly seen at night.
Yes
Of the 5 parks where we can rate Desert Nightsnake sightings, Saguaro National Park has the highest daily chance: about 10%. Next come Death Valley National Park (United States, about 10%) and Zion National Park (United States, about 10%).
Same family: Colubridae
The closest relatives of the Desert Nightsnake that you can see in Saguaro National Park (family Colubridae, Colubrid Snakes) are Gopher Snake (about 30%), Coachwhip (about 20%) and Long-nosed Snake (about 20%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Desert Nightsnake is recorded against all the reptiles logged in Saguaro National Park (43 verified sightings from 2019 to 2026), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
