Nerodia rhombifer
Silhouette: Beth Reinke · PhyloPic
In 3 days ~40% in a week ~70%
Nerodia rhombifer, commonly known as the diamondback water snake, is a species of nonvenomous natricine colubrid endemic to the central United States and northern Mexico. There are three recognized subspecies of N. rhombifer, including the nominotypical subspecies.
The species was first described as Tropidonotus rhombifer by Edward Hallowell in 1852. The diamondback water snake is predominantly brown, dark brown, or dark olive green in color, with a black net-like pattern along the back, with each spot being vaguely diamond-shaped. Dark vertical bars and lighter coloring are often present down the sides of the snake. In typical counter-colored fashion, the underside is generally a yellow or lighter brown color, often with black blotching.
The dorsal scales are heavily keeled, giving the snake a rough texture. The dorsal scales are arranged in 25 or 27 rows at midbody. There are usually 3 postoculars. Adult males have multiple papillae (tubercles) on the under surface of the chin, which are not found on any other species of snake in the United States.
Nerodia rhombifer grows to an average total length (including tail) of 76–122 cm (30... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cumbres de Monterrey National Park | 🇲🇽 Mexico |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | San Antonio | 🇺🇸 United States | |
| 2 | Houston | 🇺🇸 United States | |
| 3 | Dallas | 🇺🇸 United States | |
| 4 | Austin | 🇺🇸 United States | |
| 5 | Monterrey | 🇲🇽 México |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | San Antonio Zoo | 🇺🇸 United States | |
| 2 | Leningrad Zoo | 🇷🇺 Russia | |
| 3 | Gran Acuario de Mazatlán "Mar de Cortés" | 🇲🇽 Mexico | |
| 4 | Oklahoma Aquarium | 🇺🇸 United States |
Possible
About 20% of wildlife watchers report a Diamondback Watersnake sighting in San Antonio on a given day, based on 279 verified sightings from GBIF citizen-science data. It is the 7th most-seen of the 33 reptiles we can rate there. Over three days the chance rises to about 40%, and over a week to about 70%, if each day is a fresh chance.
June
In that month about 30% of wildlife watchers report a Diamondback Watersnake in San Antonio on a given day, against under 5% in January, the lowest month.
Between 9 pm and midnight
Across all the parks we cover, that three-hour window holds the most Diamondback Watersnake sightings with a recorded time, and about 6 in 10 of them come between 6 pm and 6 am: it is seen both by day and at night.
Yes
Of the 5 cities where we can rate Diamondback Watersnake sightings, San Antonio has the highest daily chance: about 20%. Next come Houston (United States, about 10%) and Dallas (United States, about 10%).
GBIF citizen-science records
It is estimated from how often the Diamondback Watersnake is recorded against all the reptiles logged in San Antonio (279 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.
