Contia tenuis
Silhouette: Alex Slavenko · PhyloPic
In 3 days ~10% in a week ~30%
The sharp-tailed snake or sharptail snake (Contia tenuis) is a small species of nonvenomous snake in the family Colubridae. The species is endemic to the Western United States and British Columbia. Additional common names for C. tenuis include brown snake, gentle brown snake, Oregon worm snake, Pacific brown snake, Pacific ground snake, and purple-tailed snake.
C. tenuis is distributed through the states of California, Oregon, and Washington, as well as British Columbia, Canada: Southern Vancouver Island, British Columbia around Victoria, British Columbia, in Pemberton, British Columbia and newly discovered in 2026 on Lasqueti Island, British Columbia.
The sharp-tailed snake has an average total length (including tail) of 12–18 in (30–46 cm) as an adult. It is distinguished by its sharp tail spine, which is the protruding tip of the last tail vertebra. The spine is not toxic and cannot injure humans. Rather, the tail is used to stabilize small prey, such as slugs, for consumption. The dorsal surface ranges in color from grayish brown to brown to brick red, with bubble-gum pink and peachy-orange specimens occasionally found... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sequoia and Kings Canyon National Parks | 🇺🇸 United States | |
| 2 | Yosemite National Park | 🇺🇸 United States |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sacramento | 🇺🇸 United States | |
| 2 | San Francisco | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Sharp-tailed Snake sighting in San Francisco on a given day, based on 133 verified sightings from GBIF citizen-science data. It is the 8th most-seen of the 21 reptiles we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
February–April and October–November
In those months about 10% of wildlife watchers report a Sharp-tailed Snake in San Francisco on a given day, against under 5% in May–September and December–January, the lowest months.
Between 4 and 7 pm
Across all the parks we cover, that three-hour window holds the most Sharp-tailed Snake sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is seen both by day and at night.
2nd of 2
Of the 2 cities where we can rate Sharp-tailed Snake sightings, San Francisco ranks 2nd at under 5%. The best odds are in Sacramento (United States, about 10%).
Same family: Colubridae
The closest relatives of the Sharp-tailed Snake that you can see in San Francisco (family Colubridae, Colubrid Snakes) are Gopher Snake (about 10%), Western Terrestrial Garter Snake (about 10%) and Ringneck Snake (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Sharp-tailed Snake is recorded against all the reptiles logged in San Francisco (133 verified sightings), 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.
