Hydrodynastes gigas
Silhouette: Alex Slavenko · PhyloPic
In 3 days ~40% in a week ~70%
Hydrodynastes gigas is a New World species of large dipsadine snake endemic to South America. Aglyphous snake with enlarged posterior maxillary teeth, not grooved, associated with Duvernoy's gland secretions. endemic to South America. Common names include false cobra, false water cobra, South American water cobra, and Brazilian smooth snake. It is also sometimes referred to as boipevaçu, ñacaniná or yacaniná, from the Guarani ñakanina ('alert head'), mboi-peba, surucucu-do-pantanal, and víbora ladradora ('barking snake').
A mildly venomous species, the false water cobra is so named because when it is threatened, it "hoods" as a true cobra (genus Naja) does. Unlike a true cobra, however, it does not rear up, but instead remains horizontal. No valid subspecies are currently recognized.
H. gigas is a large dipsadine snake that may exceed 3 m (10 ft) in length, with most adult specimens reaching about 2 m (7 ft) in length. The average weight is around 1.6 kg (3.5 lb), but some mature specimens can weigh up to 4.5 kg (9.9 lb). This species exhibits sexual dimorphism, with males being much smaller than females. The common name false water cobra is an allusion to its ability... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Iberá National Park | 🇦🇷 Argentina |
More parks will be added in future updates.
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | Moscow Zoo | 🇷🇺 Russia | |
| 2 | National Zoological Park | 🇺🇸 United States | |
| 3 | ZooParc de Beauval | 🇫🇷 France | |
| 4 | Zoo Miami | 🇺🇸 United States | |
| 5 | Milwaukee County Zoo | 🇺🇸 United States | |
| 6 | Toledo Zoo | 🇺🇸 United States | |
| 7 | Woodland Park Zoo | 🇺🇸 United States | |
| 8 | San Antonio Zoo | 🇺🇸 United States | |
| 9 | Minsk Zoo | 🇧🇾 Belarus | |
| 10 | Municipal Zoological Park Quinzinho de Barros | 🇧🇷 Brazil | |
| 11 | Alligator Adventure | 🇺🇸 United States | |
| 12 | Zoológico de Fauna Sudamericana | 🇧🇴 Bolivia | |
| 13 | Chattanooga Zoo at Warner Park | 🇺🇸 United States | |
| 14 | Vancouver Aquarium | 🇨🇦 Canada | |
| 15 | Blue Planet Aquarium | 🇬🇧 United Kingdom | |
| 16 | Дэльфінарый | 🇧🇾 Belarus |
Possible
About 20% of wildlife watchers report a False Water Cobra sighting in Iberá National Park on a given day, based on 9 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 6th most-seen of the 10 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.
August
In that month about 40% of wildlife watchers report a False Water Cobra in Iberá National Park on a given day, against under 5% in December to June, the lowest months.
Between 1 and 4 pm
Across all the parks we cover, that three-hour window holds the most False Water Cobra sightings with a recorded time, and about 8 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
Only Iberá National Park, in our data
Iberá National Park is the only park on Wallace's Line with enough records to rate False Water Cobra sightings: about 20% of wildlife watchers there report one on a given day.
Same family: Colubridae
The closest relatives of the False Water Cobra that you can see in Iberá National Park (family Colubridae, Colubrid Snakes) are Wagler's Snake (about 10%) and Jaeger's Ground Snake (about 10%), with each one's daily chance of a sighting.
GBIF citizen-science records
It is estimated from how often the False Water Cobra is recorded against all the reptiles logged in Iberá National Park (9 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.
