Bothrops atrox
Silhouette: Steven Traver · PhyloPic
In 3 days ~50% in a week ~80%
Bothrops atrox — also known as the common lancehead, fer-de-lance, barba amarilla, and mapepire balsain — is a highly venomous pit viper species found in the tropical lowlands of northern South America east of the Andes, as well as the Caribbean island of Trinidad. No subspecies are currently recognized.
The common lancehead was one of the many reptile and amphibian species described by Carl Linnaeus in the landmark 1758 10th edition of his Systema Naturae, where it was given the binomial name Coluber atrox. The taxonomy of this species is controversial; it may include B. leucurus and B. moojeni, and some of its populations are sometimes said to be separate species. B. asper was formerly included in this species, but most authorities now consider it distinct.
Common names include lancehead, fer-de-lance, barba amarilla, and mapepire balsain, among others. The Spanish common name barba amarilla (yellow beard), an allusion to the pale-yellow chin color, is also used in English. In Venezuela, it is called mapanare. In Colombia, it is known as mapaná (Llanos of Vichada) and talla equis. In Guyana and Suriname, it is called labaria or labarria. In Peru, it is... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Brownsberg Nature Park | 🇸🇷 Suriname | |
| 2 | Manu National Park | 🇵🇪 Peru | |
| 3 | Henri Pittier National Park | 🇻🇪 Venezuela | |
| 4 | Yasuní National Park | 🇪🇨 Ecuador | |
| 5 | Podocarpus National Park | 🇪🇨 Ecuador | |
| 6 | Tambopata National Reserve | 🇵🇪 Peru |
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Manaus | 🇧🇷 Brazil |
| # | Zoo / Centre | Country | |
|---|---|---|---|
| 1 | ABQ BioPark Zoo | 🇺🇸 United States | |
| 2 | Rio de Janeiro Zoological Garden | 🇧🇷 Brazil | |
| 3 | Amaru | 🇪🇨 Ecuador | |
| 4 | Bioparque Los Ocarros | 🇨🇴 Colombia | |
| 5 | Refugio Silvestre Yanacocha | 🇪🇨 Ecuador | |
| 6 | Yanacocha Animal Rescue Centre | 🇪🇨 Ecuador | |
| 7 | Dantas | 🇨🇴 Colombia |
Possible
About 20% of wildlife watchers report a Barba Amarilla sighting in Yasuní National Park on a given day, based on 19 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 22nd most-seen of the 49 reptiles we can rate there. Over three days the chance rises to about 50%, and over a week to about 80%, if each day is a fresh chance.
June, August and December
In those months about 30% of wildlife watchers report a Barba Amarilla in Yasuní National Park on a given day, against under 5% in March–April and October–November, the lowest months.
Between 8 and 11 pm
Across all the parks we cover, that three-hour window holds the most Barba Amarilla 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.
4th of 6
Of the 6 parks where we can rate Barba Amarilla sightings, Yasuní National Park ranks 4th at about 20%. The best odds are in Brownsberg Nature Park (Suriname, about 70%), Manu National Park (Peru, about 30%) and Henri Pittier National Park (Venezuela, about 20%). All parks ranked.
GBIF citizen-science records
It is estimated from how often the Barba Amarilla is recorded against all the reptiles logged in Yasuní National Park (19 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.
