Tantilla planiceps
Silhouette: Jessica Tingle · PhyloPic
In 3 days ~10%
The western black-headed snake (Tantilla planiceps), also known as the California black-headed snake, is a snake species endemic to the Californias (the U.S. State of California and the Baja California Peninsula in Mexico), as north as the San Francisco Bay and as far east as western Utah, and Texas. It lives in mostly moist pockets in mostly arid or semiarid environments and spends much of its life underground. It has a flattened head as most crevice-dwellers and is seven to fifteen inches in size. It is brown, slender, olive-gray, with a black head bordered by a white collar. Its habitat is often in woodland, desert areas, grassland and along arroyos in areas that are wet in a usually dry region.
The western black-headed snake is a member of a larger natural group of small New World terrestrial colubrids, where some of the related species include sand snake (Chilomeniscus), shovel-nosed snake (Chionactis), and the ground snake (Sonora). The western black-headed snake is the sister species of Tantilla yaquia of southern Arizona. They are also related to Tantilla gracilis, Tantilla atriceps, Tantilla hobartsmithi and Tantilla nigriceps, all species endemic to the southwestern United States. It is visually similar to the southwestern black-headed snake (T. hobartsmithi). Although they usually appear singly or in pairs, as many as six individual snakes have been observed together. They prey on arthropods, particularly centipedes and beetle larvae, as well as spiders, insects, slugs, and earthworms. They are highly secretive and rarely seen, spending much time under objects, especially during daytime. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Los Angeles | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Western Black-headed Snake sighting in Los Angeles on a given day, based on 12 verified sightings from GBIF citizen-science data. It is the 28th most-seen of the 37 reptiles we can rate there. Over three days the chance rises to about 10%, if each day is a fresh chance.
Any time of year
In every month with enough records, under 5% of wildlife watchers report a Western Black-headed Snake in Los Angeles on a given day, so our monthly data shows no clear season.
Between 6 and 9 pm
Across all the parks we cover, that three-hour window holds the most Western Black-headed Snake sightings with a recorded time, and about 6 in 10 of them come between 6 am and 6 pm: it is most active around dawn and dusk.
Only Los Angeles, in our data
Los Angeles is the only city on Wallace's Line with enough records to rate Western Black-headed Snake sightings: under 5% of wildlife watchers there report one on a given day.
Same family: Colubridae
The closest relatives of the Western Black-headed Snake that you can see in Los Angeles (family Colubridae, Colubrid Snakes) are Gopher Snake (about 10%), California King Snake (about 10%) and Striped Racer (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the Western Black-headed Snake is recorded against all the reptiles logged in Los Angeles (12 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.
