Bothrops jararaca
Silhouette: Steven Traver · PhyloPic
In 3 days ~30% in a week ~50%
Bothrops jararaca—known as the jararaca or yarara—is a highly venomous pit viper species endemic to South America in southern Brazil, Paraguay, and northern Argentina. The specific name, jararaca, is derived from Old Tupi îararaka. Within its geographic range, it is often abundant and is an important cause of snakebite. No subspecies are currently recognized.
The drugs known as angiotensin converting enzyme (ACE) inhibitors, used for the treatment of hypertension and some types of congestive heart failure, were developed from a peptide found in the venom of this species. This is a slender and terrestrial species that grows to a maximum total length of 160 cm (63 in), although the average total length is much less.
The head scalation includes 5–12 intersupraoculars that are weakly keeled, 7–9 supralabials (usually 8) of which the second is fused with the prelacunal to form a lacunolabial, and 9–13 sublabials (usually 10–12). The midbody has 20–27 rows of dorsal scales (usually 23–25). The ventrals number 170–216 (rarely 218) and the 51–71 subcaudals are mostly paired.
The color pattern is extremely variable, consisting of a dorsal ground color that may be tan, brown... Wikipedia →
Recording0:11
Brazil · 2025
© Unidade de Conservação Ambiental Desterro-UFSC · iNaturalist · CC BY-NC 4.0
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Serra dos Órgãos National Park | 🇧🇷 Brazil | |
| 2 | Itatiaia National Park | 🇧🇷 Brazil | |
| 3 | Tijuca National Park | 🇧🇷 Brazil |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Porto Alegre | 🇧🇷 Brazil | |
| 2 | Rio de Janeiro | 🇧🇷 Brazil | |
| 3 | São Paulo | 🇧🇷 Brazil |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | São Paulo Zoo | 🇧🇷 Brazil | |
| 2 | Fort Worth Zoo | 🇺🇸 United States |
With luck
About 10% of wildlife watchers report a Yarará Lancehead sighting in Tijuca National Park on a given day, based on 20 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 7th most-seen of the 21 reptiles we can rate there. Over three days the chance rises to about 30%, and over a week to about 50%, if each day is a fresh chance.
January
In that month about 20% of wildlife watchers report a Yarará Lancehead in Tijuca National Park on a given day, against under 5% in July and September–October, the lowest months. That is one of Tijuca National Park's wettest months, with about 180 mm of rain against 40 mm in July.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Yarará Lancehead sightings with a recorded time, and about 7 in 10 of them come between 6 am and 6 pm: it is a daytime animal.
3rd of 3
Of the 3 parks where we can rate Yarará Lancehead sightings, Tijuca National Park ranks 3rd at about 10%. The best odds are in Serra dos Órgãos National Park (Brazil, about 30%) and Itatiaia National Park (Brazil, about 20%).
GBIF citizen-science records
It is estimated from how often the Yarará Lancehead is recorded against all the reptiles logged in Tijuca National Park (20 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.
